Maintenance instructions

BPW Trailer Axles and Suspensions

§

BPW-W 33111501e
Page 2 BPW-W 33111501e

Contents

1. Important information....................................................................................................................... Page 3

1.1 General  Page 3
1.2. Maintenance, repair and spare parts Page 3
1.3. Definition On-Road / Off-Road Page 3
1.4. Latest version  Page 3
2. Safety instructions �������������������������������������������������������������������������������������������������������������������������� Page 4
3. BPW Trailer axles / BPW Steering axles ���������������������������������������������������������������������������������������� Page 6
3.1 Lubrication Page 6
3.2 Maintenance Work and Visual Inspection
3.2.1 General Page 23
3.2.3 Drum brakes Page 24
3.2.3 Disc brakes, brake types TSB 3709, TSB 4309, TSB 4312 Page 40
3.2.4 Disc brakes, brake types SB 3308, SB 3745, SB 4309, SB 4345 Page 50
4. BPW Air suspension, series EAC (ECO Air COMPACT)��������������������������������������������������������������� Page 64
4.1 Overview, Maintenance Work and Visual Inspection Page 64
4.2 Maintenance Work and Visual Inspection Page 66
5. BPW Air suspension, series O, SL, AL ����������������������������������������������������������������������������������������� Page 72
5.1 Overview, Lubrication and Maintenance Work, Visual Inspection Page 72
5.2 Lubrication Page 76
5.3 Maintenance Work and Visual Inspection Page 76
6. BPW Mechanical suspensions (leaf springs), series ECO Cargo VB / VB HD �������������������������� Page 86
6.1 Overview, Lubrication and Maintenance Work, Visual Inspection Page 86
6.2 Lubrication Page 88
6.3 Maintenance Work and Visual Inspection Page 89
7. BPW Mechanical suspensions (leaf springs), series ECO Cargo W / BW / GW������������������������ Page 92
7.1 Overview, Lubrication and Maintenance Work, Visual Inspection Page 92
7.2 Lubrication Page 94
7.3 Maintenance Work and Visual Inspection Page 95
BPW-W 33111501e Page 3

Important information 1

1.1. General
The following maintenance instructions apply to BPW trailer axles and BPW suspensions for drawbar trailers and
semi-trailers (manufactured from 1982 onwards). They are part of the Terms and Conditions for the ECO Plus
Warranty (see warranty documents at www.bpw.de).
Carry out the latest maintenance instructions in accordance with the prescribed intervals in order to main-
tain the safe operation and roadworthiness of the vehicle. The latest version of the maintenance instructions can
always be found at www.bpw.de. The latest printed version is available by post on request. The relevant operation
and service regulations of the vehicle manufacturer and the manufacturers of other vehicle parts must also be
adhered to.
These maintenance intervals are set out in calendar weeks and are listed to coincide with statutory testing require-
ments (ZU, HU, BSU).

1.2. Maintenance, Repair and Spare Parts

Rectification of any discovered defects or replacement of worn parts should be carried out by a BPW Service
Centre or BPW Direct Service Partner unless the vehicle owner has the appropriate trained personnel, facilities,
equipment and workshop manuals available and possesses an official certificate to perform interim inspections or
special brake inspections.
We strongly recommend that only genuine BPW parts, brake linings in particular, are used when fitting spare parts.
Parts authorised by BPW for trailer axles and axle units are regularly subjected to special inspections. BPW accepts
product responsibility for them.
BPW is unable to determine whether all third party products can be used with BPW trailer axles and axle suspensions
without any safety risk; this also applies even if an authorised testing organisation has accepted the product.
The ECO Plus Warranty (see warranty documents) will cease to apply if spare parts other than genuine BPW spare
parts are used.

1.3. Definition On-Road / Off-Road

The term „On-Road“ refers to roads having a sealed and metalled surface, in other words with an asphalt or concrete
surface. Gravel roads are regarded as being Off-Road. A vehicle is also regarded as being in Off-Road operation even
if it departs from sealed surfaces under operating conditions for only short periods. Off-Road operation is assumed
in all cases in tippers and vehicles with comparable applications.

1.4. Latest Version

The latest maintenance instructions are dated 01.05.2015 and replace maintenance instructions BPW-W 33111401e.
All previous maintenance instructions become invalid. We reserve the right to make any changes.

Current versions and additional information can be found online at www.bpw.de.

Page 4 BPW-W 33111501e

2 Safety instructions

The following instructions should also be adhered to by the driver in addition to the statutory regulations:

In case of a new vehicle:

– After the first run under load conditions and after each wheel change:
• Check wheel nuts for firm seating using a torque wrench. See point 1 on page 26, 42, 52.

– After the first two weeks (after the first runs under load conditions):
• Check that the bolt connections of the spring attachments and axle steering devices are secure, depending
on the application (On-Road or Off-Road). Observe the stipulated tightening torques.

• Air suspensions: see 4 to 9 page 78 - 82

• Leaf-spring suspensions: see 2 and 4 page 89 - 90

see 1 and 3 page 95

Prior to each run:

– Air reservoir of the brake and air suspension set at operating pressure.
– Visual inspection:
• Tyre pressure
• Wheel fixings
• Check operation of lighting and braking systems
• Drum brake: Check the brake pad/lining thickness when the brake pad/lining wear indicator is in the
horizontal position.
• Disc brake: Check the remaining brake pad / lining thickness.
Type TSB: The thickness of the remaining pad can be determined by the position of the caliper in relation
to the brake carrier (see page 43).
Type SB: The thickness of the remaining pad can be detected by the position of the brake caliper in
relation to the stationary guide sleeve (see pages 53 - 54).
• Check that the air suspension has reached ride height and the air bags are not creased. This also applies
after rapid loading or unloading.
• Normal ride level of the air bags, check air bags are not creased. This also applies to rapid loading or
unloading.

In the event of daily frost or in accordance with manufacturer’s instructions:

– Drain off condensation water via the drainage valve at the bottom of the air reservoirs.
– Check the valve system.
BPW-W 33111501e Page 5

Quarterly:
– Clean line filter (in accordance with manufacturer’s instructions).

Proper use of the braking system:

– In the event of premature wear of the brake pads, a tractor/trailer harmonisation (according to ISO 20918 is to
be carried out.
– To maintain the efficiency of the braking system, regular use of the wheel brakes with the appropriate level of
heat generation is recommended.
– Before proceeding with an HU or SP (PTI), the braking system performance where applicable, must be measured
(see ISO 7634).
– The appropriate installation and operating instructions for BPW brake components (see www.bpw.de) should be
observed.

We wish you a safe journey!

Page 6 BPW-W 33111501e

3 BPW Trailer axles / BPW Steering axles

3.1 Lubrication

Overview At every BPW re-

brake lining commendation.
replacement 2) Does not affect

thereafter every 3 years

warranty

every 500,000 km 2)
Every 26 weeks 1) 2)
Every 12 weeks

3 years or min.
Every 6 weeks

Every 2 years

Every 3 years
After 5 years,
Latest every

Latest every
annually 1)

Annually
2 years
Latest
For detailed description see pages 8 - 21

1 Steering pivot bearing, top and bottom 1

2 Brake camshaft bearing, outer and inner

On-Road conditions 2
Off-Road conditions 2
Outside Europe 2
3 Slack adjusters manual 3

Slack adjuster ECO-Master:

On-Road conditions 3
Off-Road conditions 3
Outside Europe 3

4 Brake shoes with closed anchor eye 4

5 ECO Plus 3, ECO Plus 2 and ECOPlus Unit:

On-Road conditions 5
Off-Road conditions 5
Outside Europe: On-Road conditions 5
Outside Europe: Off-Road conditions 5

ECO Unit 5
Outside Europe 5
Conventional hub bearing 5

For positions 1 to 3 the use of a high-pressure central lubrication system which is capable of feeding special
longlife grease of consistency class 2-3 is permissible. The use of liquid lubricants is not permitted!
1) After a long idle period, prior to initial operation actuate the brake lever and lubricate the brake camshaft bearing.
2) With use under extreme conditions (e.g. extreme Off-Road use) more frequent lubrication with high pressure grease is necessary.
BPW-W 33111501e Page 7

5 4 2 2 3

Trailer axles
Series H / K / N

5 4 1

Series ...LL
2 3

Series SH / SKH
Page 8 BPW-W 33111501e

3 BPW Trailer axles / BPW Steering axles

3.1 Lubrication

Note: After cleaning the vehicle with high-pressure

cleaners, all lubrication points must be relubricated.
1

1 Steering pivot bearing, top and bottom

– every 6 weeks –

Lift axle in order to relieve the steering pivot

bearing. Grease lubrication nipple with BPW spe-
cial longlife grease ECO-LiPlus until fresh grease
emerges from the bearing points.
1

2 Brake camshaft bearing, outer and inner

Low maintenance brake camshaft bearing

(from year of manufacture 1993)

– every year and with each brake lining change in

On-Road use –
– every 6 months in Off-Road use and in use
outside Europe –

Prevent the vehicle from rolling away.

Release the service brakes and the handbrake. 2
Lubricate the brake camshaft bearing through the
grease nipple with BPW special longlife grease
ECO-LiPlus until fresh grease emerges from the
bearing points.

+ Important!
Use of other grease is not permitted!

2
BPW-W 33111501e Page 9

3 Slack adjusters (manual)

– quarterly –

Grease lubrication nipple with BPW special longlife

Trailer axles
grease ECO-LiPlus until fresh grease emerges.

+ Automatic slack adjuster ECO-Master

– every year and with each brake lining change in 3
On-Road use –
– every 6 months in Off-Road use and in use
outside Europe –

Remove rubber seal cap. Grease with BPW spe-

cial longlife grease ECO-LiPlus (approx. 80 g) until
sufficient new grease emerges from the adjustment
bolt.

Turn back adjustment screw (keep clutch sleeve

pressed down) by approx. one turn using a ring
spanner. Actuate the brake lever several times by
hand. The adjustment must be carried out smoothly.
If necessary, repeat several times.

Once again only use BPW special longlife grease

ECO-LiPlus.
Install seal cap.

Adjust the brake - see relevant workshop manual.

3

4 Brake shoes with closed anchor eye

– every 2 years and with each brake lining change –

Clean the bush and roller, check for wear and, if

necessary replace. Smear BPW special longlife
grease ECO-LiPlus onto bearing points of brake
shoe.
4
Page 10 BPW-W 33111501e

3 BPW Trailer axles / BPW Steering axles

3.1 Lubrication

5 ECO Plus 3 Unit

– for the first time after 5 years in On-Road use,
or every 3 years in Off-Road use in Europe,
then at least every 3 years depending on
operating conditions –

– every 2 years in On-Road use or every year in

Off-Road use outside Europe –

Thoroughly clean taper roller bearings and seals

(using e.g. diesel oil), dry and check for re-useability.
Replace grease seal.

(Recommendation: Renew the tapered roller bea-

rings after 5 years in On-Road and after 3 years in
Off-Road use.)

Work BPW special longlife grease ECO-LiPlus

thoroughly into the cavities between the taper
rollers and the cage in both taper roller bearings.
(For grease quantity see illustration on page 11.)
Smear any residual grease into the hub‘s outer be-
aring race.

Smear the lip of the new seal all round with BPW
special longlife grease ECO-LiPlus.

Clean the bearing seats of the axle stub (metal must

be bright, dry and free from grease). Spray with
BPW ECO Assembly and Protection Spray. Allow
to dry for about 10 minutes until the film changes to
a marked matt colour.

Install ECO unit whilst continuously rotating axle

nut of ECO unit. It should take several turns until
the clutch on the axle nut slips.

Important!
Do not use an impact driver.
Fit the retaining key in the groove between the
stub axle and the nut (do not reset the axle nut).

Insert the hooked retainer spring behind the formed

edge of the axle nut.

Insert a new O-ring into the annular groove of the

wheel hub. Apply a thin coat of BPW special long-
life grease ECO-LiPlus to the O-ring contact surface
and thread of the hub cap.

Screw on the hub cap and tighten to 350 Nm.

BPW-W 33111501e Page 11

ECO Plus 3 Unit

Trailer axles
1 2

BPW special longlife grease ECO-LiPlus

Grease quantity per taper roller bearing

1 Inner bearing 2 Outer bearing

Manual greasing 170 g 120 g

Greasing with a grease applicator 130 g 90 g

Page 12 BPW-W 33111501e

3 BPW Trailer axles / BPW Steering axles

3.1 Lubrication

+ ECO Plus 2 Unit

– for the first time after 5 years in On-Road use,
or every 3 years in Off-Road use in Europe,
then at least every 3 years depending on
operating conditions –

– every 2 years in On-Road use or every year in

Off-Road use outside Europe –

Prevent the vehicle from rolling away.

Remove the wheel.

Unscrew the cap with a 120 mm cap spanner.

Important! Position 1 Position 2

Do not use an impact driver -
bayonet lock.
Undo the cap by turning it anti-clockwise by
approx. 30° from position 1 to position 2.

When turned further the hub cap lifts clearly away

from the ECO Unit and can be removed by pulling
it away.

Remove the hooked spring ring and retaining key

from the axle bolt.

Unscrew the axle bolt, pulling the complete ECO

Unit off the bearing seats of the axle stub as you
do so.

Dismantle the ECO Unit - see the corresponding

workshop manuals.
BPW-W 33111501e Page 13

Clean the tapered roller bearings thoroughly (e.g.

with diesel oil), dry them and check if they can be
re-used. Fit a new shaft seal.

(Recommendation: Renew the tapered roller bea-

Trailer axles
rings after 5 years in On-Road use and after 3 years
in Off-Road use.)

Clean the grease cartridge and fill it on both sides

up to the edge with BPW special longlife grease
ECO-LiPlus. It is important to ensure that it is filled
without any trapped air or cavities.

Apply a ring-shaped bead of grease to the running

surfaces of the bearing outer races (see arrows in
illustration below).

+ When BPW grease applicators are used, there is

no need to fill the grease cartridge or to apply the
bead of grease.
Mount the ECO Unit.

Clean the bearing seats of the axle stub (metal must

be bright, dry and free from grease). Spray with
BPW ECO Assembly and Protection Spray. Allow
to dry for about 10 minutes until the film changes to
a marked matt colour.

BPW special longlife grease ECO-LiPlus

Grease quantity per taper roller bearing

1 2
Inner bearing Outer bearing

Manual
170 g 120 g
greasing
Greasing
with a grease 130 g 90 g
applicator

ECO Plus 2 Unit

1 2
Page 14 BPW-W 33111501e

3 BPW Trailer axles / BPW Steering axles

3.1 Lubrication

Apply only a thin layer of BPW ECO-LiPlus to the

threaded hole in the axle stub.

+ Important!
Do not apply too much grease!
It is necessary to make sure that the axle bolt can
be completely screwed into the axle stub.

Mount the ECO Unit. Guide the toothed lock washer

into the hole in the axle stub. The position of the pin
can be seen by the punched-in BPW logo in the
recess of the axle bolt.

Fasten axle bolt (SW46) whilst rotating the ECO

hub unit. It should take several turns until the
clutch on the axle bolt slips.
(Do not turn back the axle bolt).

Important!
Do not use an impact driver.
Insert the retaining key into the recess in the axle
bolt and the gearing of the toothed lock washer. (Do
not turn back the axle bolt.)

Insert the hooked spring ring into the groove of the

hexagon profile of the axle bolt.

+ Make sure that the hooked spring ring assembly

is correctly seated in the annular groove of the
axle bolt.
BPW-W 33111501e Page 15

Insert a new O-ring into the groove in the wheel hub. Position 1 Position 2
Apply a thin layer of BPW ECO-LiPlus special longlife
grease to the cap in the area of the O-ring contact
surface and the bayonet fitting.

Trailer axles
Screw on the cap with a 120 mm cap spanner.

Important!
Do not use an impact driver -
bayonet lock.
Push on the cap, see position 1.
Press on the cap and turn it by approx. 30° in a
clockwise direction to lock it in place. A tight seat is
provided when position 2 is reached.
Page 16 BPW-W 33111501e

3 BPW Trailer axles / BPW Steering axles

3.1 Lubrication

+ ECO Plus
Unit
– for the first time after 5 years in On-Road use,
or every 3 years in Off-Road use in Europe,
then at least every 3 years depending on
operating conditions –

– every 2 years in On-Road use or every year in

Off-Road use outside Europe –

Thoroughly clean taper roller bearings and seals

(using e.g. diesel oil), dry and check for re-useability.
Replace grease seal.

(Recommendation: Renew the tapered roller bea-

rings after 5 years in On-Road and after 3 years in
Off-Road use.)

Work BPW special longlife grease ECO-LiPlus

thoroughly into the cavities between the taper
rollers and the cage in both taper roller bearings.
(For grease quantity see illustration on page 17.)
Smear any residual grease into the hub‘s outer be-
aring race.

Smear the lip of the new seal all round with BPW
special longlife grease ECO-LiPlus.

Clean the bearing seats of the axle stub (metal must

be bright, dry and free from grease). Spray with
BPW ECO Assembly and Protection Spray. Allow
to dry for about 10 minutes until the film changes to
a marked matt colour.

Install ECO unit whilst continuously rotating axle

nut of ECO unit. It should take several turns until
the clutch on the axle nut slips.

Important!
Do not use an impact driver.
Fit the retaining key in the groove between the axle
stub and the nut (do not reset the axle nut).

For production date April 2000 onwards, insert the

hooked spring ring behind the edge of the axle nut
or, up to March 2000, into the thread on the axle
stub. Screw on the cap and tighten to 800 Nm.
BPW-W 33111501e Page 17

ECOPlus Unit

Trailer axles
1 2

BPW special longlife grease ECO-LiPlus

Grease quantity per taper roller bearing

1 Inner bearing 2 Outer bearing

Manual greasing 170 g 120 g

Greasing with a grease applicator 130 g 90 g

Page 18 BPW-W 33111501e

3 BPW Trailer axles / BPW Steering axles

3.1 Lubrication

+ ECO Unit
– latest every 3 years or min. every 500,000 km
(Western European road conditions), annually
in use outside Europe –

Thoroughly clean taper roller bearings and seals

(using e.g. diesel oil), dry and check for re-useability.
Replace grease seal.

Work BPW special longlife grease ECO-LiPlus

thoroughly into the cavities between the taper
rollers and the cage in both taper roller bearings.

Comply with the total grease quantity in tables

A and B .

Smear any residual grease into the hub‘s outer

bearing race. Smear the lip of the new grease
seal all round with BPW special longlife grease
ECO-LiPlus.

Clean the bearing seats of the axle stub (metal must

be bright, dry and free from grease). Spray with
BPW ECO Assembly and Protection Spray. Allow
to dry for about 10 minutes until the film changes to
a marked matt colour.

Fit the ECO Unit.

Fasten axle nut using a torque wrench whilst
rotating the ECO hub unit. It should take several
turns until the tightening torque has reached
150 Nm. Turn the nut back until the next securing
position is aligned. (max 15 degrees).

The next locking hole is reached by turning back

the asymmetrical axle nut by a maximum of 15°. Fit
pin with a snap hook.
Tighten the cap to 800 Nm.
BPW-W 33111501e Page 19

ECO Unit

Trailer axles
A B

BPW special longlife grease ECO-LiPlus

Grease quantity per taper roller bearing

Axle load A Inner bearing B Outer bearing

6000 - 9000 kg 120 g 120 g

10000 - 12000 kg 170 g 120 g

13000 - 14000 kg 230 g 150 g

Page 20 BPW-W 33111501e

3 BPW Trailer axles / BPW Steering axles

3.1 Lubrication

+ Change wheel hub bearing grease

(Conventional)
– whenever brake linings are changed: at the latest
annually or after 150,000 km –

For demounting and re-fitting of wheel hubs, see

workshop manuals.

Mark demounted wheel hubs and bearing races

so that their identity is not mistaken during
re-assembly.

Clean wheel hubs thoroughly inside and outside.

Remove old grease completely.

Thoroughly clean taper bearings (using e. g. diesel

oil) dry and check for re-useability. Replace seals.

Work BPW special longlife grease ECO-LiPlus into

the cavities between the taper rollers and cage.

Comply with total grease quantity (table A ), smear

any residual grease into the hub’s outer bearing
race.

Fit wheel hubs and adjust bearing play (see point

7 page 38).

Fill hub caps with BPW special longlife grease

ECO-LiPlus (table B ) and screw on.

For tightening torques see 5 page 31.

BPW-W 33111501e Page 21

Conventional wheel hub bearing

Trailer axles
A B

BPW special longlife grease ECO-LiPlus

Grease quantity per taper roller bearing

Axle load (Series H, K, N, M) A Inner bearing B Outer bearing (cap filling)

4000 - 5500 kg 80 g 130 g

6000 - 9000 kg 170 g 290 g
10000 - 12000 kg 180 g 320 g
13000 - 14000 kg 240 g 500 g
16000 - 18000 kg 400 g 800 g
20000 kg 440 g 900 g

Axke load (Series E and NE)

3000 kg 70 g 100 g
3500 - 3800 kg 80 g 120 g
4500 kg 90 g 180 g
Page 22 BPW-W 33111501e
BPW-W 33111501e Page 23

BPW Trailer axles / BPW Steering axles 3

Maintenance Work and Visual Inspection 3.2
General 3.2.1

In order to distribute the braking effort evenly to all the brakes in the unit, adjustment must always be carried out
according to the vehicle manufacturer‘s specifications, or after 5,000 km. Tractor units with EBS cannot have
their brakes adjusted in the normal manner. As a result, the trailer or semi-trailer merely has to be checked for compli-
ance with the EC tolerance bands. Always check the tractor vehicle if the trailer is in the EC band despite premature
brake pad wear. The EBS parameters in the tractor unit must be modified in order to improve compatibility, see ECE

Trailer axles
R 13 in this connection. Failure to do so will invalidate the warranty (see warranty documents).

Other possible solutions to premature brake pad wear:

- Prescribed maintenance work must be performed at regular intervals.
- Use the retarder or engine brake to adjust the vehicle’s speed.
- Think ahead when driving.
- Drop down to a lower gear in good time.
- BPW Disc Protector (cover plates for brake discs).

Even at high temperatures, disc brakes display stable braking properties and a high level of safety. Excessive tempe-
ratures do not make themselves apparent through brake fading and should be avoided. This effect leads to increased
wear when used under these conditions.
Page 24 BPW-W 33111501e

3 BPW Trailer axles / BPW Steering axles

3.2 Maintenance Work and Visual Inspection
3.2.2 Drum brakes

Overview

At every brake lining

Every 1 to 3 weeks

2)

latest annually 2)
Every 12 weeks

Every 26 weeks

replacement,
For detailed description, see pages 26 - 38
Disc brakes, see pages 40 - 62

Initially
Air suspension, see pages 64 - 84
Suspension, see pages 86 - 95
Maintenance work - Drum brakes
1)
1 Check wheel nuts for tightness. 1

2 With manual slack adjusters, check brake play, adjust if necessary to 2

10 - 12% of the connected brake lever length and activate by hand or with
0.5 - 0.8 bar. (Not applicable in the case of automatic slack adjusters.)

- Check the tyres for uneven wear, adjust the inflation pressure if necessary, -
according to the manufacturer‘s specifications.

3 Check brake lining thickness is at least 5 mm. (Brake SN 300 min. 7 mm 3

and N 3006 min. 2.5 mm residual lining thickness.)

4 Check brake drum for cracks and check the internal diameter. 4

5 Check caps for firm seating (not necessary with ECO Plus 3, ECO Plus 2 5
and ECOPlus axles).
3)
6 Check operation of automatic slack adjusters. 6 6
3)
Visual inspection of all component parts and welding seams for damage
° ° °
and wear.

7 Check wheel hub bearing play, adjust if necessary.

- ECO Plus 3, ECO Plus 2 and ECOPlus Unit 7
- ECO Unit, conventional bearing 7

1) After the first run under load conditions, likewise after each wheel change.
2) Under extreme conditions, increase frequency (e.g. construction sites and poor roads).
3) For use outside Europe.

Note: Components that have damage due to improper mounting are to be exchanged after a review by a
BPW Service Centre.
BPW-W 33111501e Page 25

5 7 1 4 3 2 6

Trailer axles
Series H / K / N

5 7 1 4 3

Series ....LL

2 6

5 7 1 3 4 2 6

Series NE / NM / NR / M
Page 26 BPW-W 33111501e

3 BPW Trailer axles / BPW Steering axles

3.2 Maintenance Work and Visual Inspection
3.2.2 Drum brakes

1 Check wheel nuts for tightness

– the tightening torque of the wheel nuts must be
checked after the first high load journey as well
as after each wheel change and, if appropriate,
retightened to the prescribed value –

Tighten wheel nuts diagonally using a torque

wrench to the tightening torque shown in the table.

In the case of Trilex-wheels tighten the nuts conse-

cutively several times around.

Wheel contact surfaces should not have additional

coats of paint (risk of the wheels becoming deta-
ched!)

Tightening torque for wheel nuts

It is imperative that the prescribed tightening torques are adhered to in order to ensure the
wheels are securely fastened! The wheel studs must be clean and free of damage and the nuts
must be easily tightened and loosened. If needed, lightly oil the contact surface between the
wheel nut and the pressure disc. Do not oil or grease the thread of the wheel studs and wheel nuts.

Stud alignment Tightening torque

M 14 x 1.5 125 Nm (120 - 130 Nm)
M 18 x 1.5 290 Nm (275 - 305 Nm)
M 20 x 1.5 380 Nm (360 - 400 Nm)
M 22 x 1.5 510 Nm (485 - 535 Nm)
M 22 x 2 460 Nm (435 - 485 Nm)

Spigot alignment Tightening torque Wheel nut with collar

M 18 x 1.5 350 Nm (330 - 370 Nm)
M 20 x 1.5 480 Nm (455 - 505 Nm)
M 22 x 1.5 630 Nm (600 - 660 Nm)
M 22 x 1.5 alloy wheels 630 Nm (600 - 660 Nm)
M 24 x 1.5 860 Nm (820 - 900 Nm)

Trilex-wheels Tightening torque

M 18 x 2 285 Nm (270 - 300 Nm)
M 20 x 2 335 Nm (320 - 350 Nm)

Japan connection Tightening torque

M 20 x 1.5 570 Nm (540 - 600 Nm)
M 30 x 1.5 570 Nm (540 - 600 Nm)
BPW-W 33111501e Page 27

The torque values shown below can be achieved

using a normal wheel nut spanner (vehicle tool kit)
and a length of tubing. B
However always check with a torque wrench as

Trailer axles
soon as possible afterwards.

To achieve tightening torques with on-board tools

Tightening torque Tubing length „A“ Tubing length „B“

300 mm 90 - 105 kg
350 mm 78 - 89 kg
270 - 310 Nm
400 mm 68 - 78 kg

350 mm 91 - 99 kg
400 mm 80 - 88 kg
320 - 350 Nm
450 mm 71 - 78 kg
500 mm 64 - 70 kg

400 mm 90 - 99 kg
450 mm 80 - 89 kg
360 - 400 Nm
500 mm 72 - 80 kg
600 mm 60 - 67 kg

500 mm 88 - 96 kg
600 mm 73 - 80 kg
440 - 480 Nm
700 mm 63 - 69 kg

600 mm 80 - 90 kg
700 mm 67 - 77 kg
480 - 540 Nm
800 mm 60 - 67 kg

700 mm 85 - 95 kg
800 mm 75 - 83 kg
600 - 660 Nm
900 mm 67 - 73 kg
1000 mm 60 - 66 kg

820 - 900 Nm 1000 mm 82 - 90 kg

Page 28 BPW-W 33111501e

3 BPW Trailer axles / BPW Steering axles

3.2 Maintenance Work and Visual Inspection
3.2.2 Drum brakes

2 Check and adjust wheel brake play with manual

slack adjusters
– frequent checks are necessary –
– depending upon application every 1 to 3 weeks – a

Actuate slack adjusters by hand, pulling against the

return spring. If there is more than 35 mm of play,
the slack adjuster must be reset. This can be done B
by adjusting the nut on the slack adjuster as shown.

Adjust the play ”a” to 10 -12% of the connected

brake lever length ”B”, e.g. lever length 150 mm =
15 - 18 mm of play.

Automatic slack adjusters make this adjustment

automatically whenever the camshaft is rotated by
more than 17.5°.

- Check the tyres for uneven wear, adjust the

inflation pressure if necessary according to the
manufacturer’s specifications.
– quarterly –
BPW-W 33111501e Page 29

3 Check brake lining thickness

– quarterly –

Open inspection hole by folding back the rubber

Trailer axles
flap (not required with ECO Drum brakes).

The brake lining should be replaced at a residu-

al lining thickness of 5 mm, SN 300 min. 7 mm,
N 3006 min. 2.5 mm (check with slide gauge) or on
reaching the bottom of the indicator machined into
the edge of the lining.
3 3
Re-insert the rubber flap.
ECO Drum ECO Drum / BPW 95

If brake lining wear indicators are fitted to the slack

adjusters, the minimum thickness of the brake
linings is indicated by the horizontal position of the
lever (when the brake is released).

The Brake Monitor displays the “Service” signal

when the wear sensor for drum brakes is installed.
There is no warning function. ON

Gehäuse nur mit feuchten Tuch reinigen

WARNING
90°
In certain cases the slack adjusters may not
SERVICE
be fitted in the normal (i.e. vertical) position.
In such instances, the position of the wear
BPW Bergische Achsen Kommanditgesellschaft . D-51674 Wiehl

indicator will also be different. Linings should

be changed when the wear indicator is
approximately at right angles to the brake lever.

SN 420, SN 360 min. 5 mm

SN 300 min. 7 mm
N 3006 min. 2.5 mm
Page 30 BPW-W 33111501e

3 BPW Trailer axles / BPW Steering axles

3.2 Maintenance Work and Visual Inspection
3.2.2 Drum brakes

4 Check the brake drum for cracks and the Wearing edge
internal diameter of brake lining
– quarterly –

Check the condition of the brake drum and that

there is adequate remaining thickness. If the wear
is approaching the wear edge, measure the bra-
ke drum and renew it if the maximum permitted
amount of wear has been reached. Wearing edge
of brake drum

Max. amounts of wear, measured at the position

with the greatest wear:

Brake Brake shoe Ø Ø

width Max. amount Skimming Wearing ed EC
(mm) of wear (mm) size (mm)
g e of br
ake d
ru m
O
SN 420 120 / 160 424 423
SN 420 180 / 200 / 220 425.5 424
SN 360 160 / 200 364 363
SN 300 100 / 150 / 200 304 303
FL 300 80 303 302

Wearing edge of brake lining

Wearing edge
of brake drum
Brake drum

Brake lining Wearing edge

of brake lining
BPW-W 33111501e Page 31

5 Check caps for firm seating

– every 6 months –
(not necessary with ECO Plus 3, ECO Plus 2 and
ECOPlus axles)

Trailer axles
Check caps for tightness using a torque wrench or
power tool.

Tightening torque:
Cap for
ECO Plus 3 9 t 350 Nm
ECOPlus / ECO Unit 6 - 12 t 800 Nm
Steel cap 6 - 12 t 500 Nm
Steel cap 14 t 800 Nm
Alloy cap 6 - 12 t 350 Nm

Steel cap 5.5 t 500 Nm

Steel cap 6 - 16 t 700 Nm
Alloy cap 5.5 - 12t 350 Nm

In an emergency the caps can be tightened using a

normal cap spanner (vehicle tool kit) by striking the
latter with a hammer, or also with the aid of a piece
of tubing placed over the wheel nut.

Caps with integrated hubodometers must be fitted

and dismantled using only torque controlled (DO
NOT USE AIR IMPACT WRENCHES!) air guns or
manually with a torque wrench.

Tighten to the correct tightening torque as soon

as possible.

+ Caps on ECO Plus 2 axles are provided with a Position 1 Position 2

bayonet fitting. Check for firm seating.
Position 1: Hub cap seated loosely on the Unit.

Position 2: Hub cap seated firmly on the Unit.

Page 32 BPW-W 33111501e

3 BPW Trailer axles / BPW Steering axles

3.2 Maintenance Work and Visual Inspection
3.2.2 Drum brakes

6 Check operation of the automatic slack adjusters a

– every 6 months –
– quarterly in use outside Europe (e.g. within the
scope of the statutory checks) –
B
Prevent the vehicle from rolling away.
Release the service brakes and the handbrake.

Free play check:

Operate the slack adjuster by hand or with 0.8 bar. In
this case, the free play ”a” corresponds to 10 - 15 %
of the connected brake lever length ”B”, e.g. brake
lever length 150 mm = free play 15 - 22 mm.

Check the adjustment if the free play is not within

tolerance:

Remove rubber seal cap. Keep clutch sleeve pressed

down and turn back adjustment bolt (arrow) by ap-
prox. 3/4 of a turn in a counterclockwise direction
using a ring spanner. A play of at least 50 mm with a
lever length of 150 mm must be available.

Actuate the brake lever several times by hand.

When this is done automatic adjustment must take
place smoothly. Engagement of the clutch coupling
is audible and on the return stroke the adjustment
bolt turns slightly in a clockwise direction. Grease
with ECO-LiPlus, see also 3 on page 9.

Fit seal cap.

Adjust the brake, see relevant workshop manual.

° Visual inspection
– every 6 months –
– quarterly in use outside Europe –

Check all components and welding seams for

damage and wear.
BPW-W 33111501e Page 33

7 Check wheel hub bearing play

– ECO Plus 3, ECO Plus 2 and ECOPlus Unit at every
brake lining replacement, latest annually –

– ECO Unit und conventional hub bearing every

Trailer axles
6 months –

Prevent the vehicle from rolling away.

In order to check the wheel hub bearing play, lift

the axle until the wheels are off the ground.
Release the brake. Apply a lever between the tyre
and the ground and check the play.

If bearing play is detected - ECO Plus 3 Unit:

Adjust the bearing play

1. Unscrew the cap.

2. Remove the hooked spring ring with a wedge

from the axle nut.

3. Fasten axle nut using a hexagon socket spanner

whilst rotating the ECO hub unit. It should take
several turns until the clutch on the axle nut
slips.

Attention!
Do not use an impact driver.
4. Fit the retaining key in the groove between the
stub axle and the nut (do not reset the axle nut).

5. Insert the hooked retainer spring behind the

formed edge of the axle nut.

6. Insert a new O-ring into the annular groove of

the wheel hub. Apply a thin coat of BPW special
long-life grease ECO-LiPlus to the O-ring contact
surface and thread of the hub cap.

7. Screw on the hub cap and tighten to 350 Nm.

.
Page 34 BPW-W 33111501e

3 BPW Trailer axles / BPW Steering axles

3.2 Maintenance Work and Visual Inspection
3.2.2 Drum brakes

If bearing play is detected - ECO Plus 2 Unit:

Adjust the bearing play

1. Unscrew the cap with a 120 mm hub cap span-

ner. Undo the cap by turning it anti-clockwise by
approx. 30° from position 1 to position 2.

When turned further the hub cap lifts clearly

away from the ECO Unit and can be removed
by pulling it away.

Attention!
Do not use an impact driver -
bayonet lock.
2. Remove the hooked spring ring and retaining
key from the axle bolt.

Position 1 Position 2

3. Use hex spanner (SW 46 mm) to fasten axle bolt

whilst rotating the ECO unit. It should take
several turns until the clutch on the axle bolt
slips.

Attention!
Do not use an impact driver.
BPW-W 33111501e Page 35

4. Insert the retaining key into the recess in the

axle bolt and the gearing of the toothed lock
washer (arrow). (Do not turn back the axle bolt.)

5. Insert the hooked spring ring into the groove of

Trailer axles
the hexagon profile of the axle bolt. Make sure
that the hooked spring ring assembly is correctly
seated in the annular groove of the axle bolt.

6. Insert a new O-ring into the groove in the wheel

hub.

7. Apply a thin layer of BPW ECO-LiPlus special Position 1 Position 2

longlife grease to the hubcap in the area of the
O-ring contact surface and the bayonet fitting.

8. Screw on the cap with a 120 mm cap spanner.

Attention!
Do not use an impact driver -
bayonet lock.
Push on the hubcap, see position 1.
Press on the hubcap and turn it by approx. 30°
in a clockwise direction to lock it in place.
A tight seat is provided when position 2 is
reached.
Page 36 BPW-W 33111501e

3 BPW Trailer axles / BPW Steering axles

3.2 Maintenance Work and Visual Inspection
3.2.2 Drum brakes

If bearing play is detected - ECOPlus Unit:

Adjust the bearing play

1. Unscrew the cap.

2. Remove the hooked spring ring with a wedge

from the axle nut.

3. Fasten axle nut using a hexagon socket spanner

whilst rotating the ECO hub unit. It should take
several turns until the clutch on the axle nut
slips.

Attention!
Do not use an impact driver.
4. Fit the retaining key in the groove between the
axle stub and the nut (do not reset the axle nut).

5. For production date April 2000 onwards, insert

the hooked spring ring behind the edge of the
axle nut or, up to March 2000, into the thread
on the axle stub.

6. Tighten the cap to 800 Nm.

BPW-W 33111501e Page 37

If bearing play is detected - ECO Unit:

Adjust the bearing play

1. Unscrew the cap.

Trailer axles
2. Loosen axle nut.

3. Fasten axle nut using a torque wrench whilst

rotating the ECO hub unit. It should take several
turns until the tightening torque has reached
150 Nm.

- If a normal axle nut spanner is used (vehicle

tool kit), tighten the axle nut until the ECO Unit
drags slightly (auxiliary solution).

4. Turn back axle nut to the next locking position

(max. 15°). The asymmetrical cap of the axle
nut enables the next locking position to be
reached after turning back max. 15°.

5. Insert bolt and locking ring.

6. Screw on caps.

Tightening torque:
Steel / cast cap 800 Nm
Aluminium cap 350 Nm
Page 38 BPW-W 33111501e

3 BPW Trailer axles / BPW Steering axles

3.2 Maintenance Work and Visual Inspection
3.2.2 Drum brakes

If bearing play is detected

- conventional hub bearing:

Adjust the bearing play

1. Unscrew the cap.

2. Remove the split pin from the axle nut.

3. Fasten the axle nut using a torque wrench and

with the continuous turning of the wheel hub.
It should take several turns until the tightening
torque has reached the desired value.

Tightening torques:
Up to an axle load of 5.5 tons = 70 Nm,
from 6 to 14 tons axle load = 150 Nm,
from 16 to 30 tons axle load = 350 Nm.

- If a normal axle nut spanner is used (vehicle

tool kit), tighten the axle nut until the wheel
bearing race drags slightly.

4. Turn back the axle nut to the next available split

pin hole. Should they already be in line turn
back to the next hole (30° at the maximum).
(Does not apply to the ECO Plus 2, ECOPlus and
ECO Unit.)

5. Insert the split pin and bend upwards slightly.

6. Refill the cap as required with BPW special

longlife grease ECO-LiPlus and replace.

For tightening torques see point 5 on page 31.

BPW-W 33111501e Page 39

Trailer axles
Page 40 BPW-W 33111501e

3 BPW Trailer axles / BPW Steering axles

3.2 Maintenance Work and Visual Inspection
3.2.3 Disc brakes, brake types: TSB 3709, TSB 4309, TSB 4312

Overview

At every brake lining

1)

1)
Every 12 weeks

Every 26 weeks

latest annually
replacement,
For detailed description, see pages 42 - 48
Disc brakes type SB, see pages 50 - 62

Initially
Air suspension, see pages 64 - 84
Suspension, see pages 86 - 95
Maintenance work - Disc brakes
Brake type: TSB 3709, TSB 4309, TSB 4312
2)
1 Check wheel nuts for tightness. 1

2 Check brake pad thickness. 2

- Visual check, check all components and welding seams for damage, wear -
and corrosion.
3)
3 Check brake disc thickness and visually check for cracks. 3 3

3)
4 Check caliper guide system. 4 4

3)
5 Check coarse dirt seals and the pressure plates. 5 5

6 Check the bearing play of the ECO Unit, adjust if necessary. 6

1) Under extreme conditions, increase frequency (e.g. Off-Road, heavy-duty braking work).
2) After the first run under load conditions and likewise after each wheel change.
3) For use outside Europe.

Note: Components that have damages due to improper mounting are to be exchanged after a review by a
BPW Service Centre.
BPW-W 33111501e Page 41

Trailer axles
6 1 2 5 4
Series SH with disc brakes type TSB

Series LL with disc brakes type TSB

Page 42 BPW-W 33111501e

3 BPW Trailer axles / BPW Steering axles

3.2 Maintenance Work and Visual Inspection
3.2.3 Disc brakes, brake types: TSB 3709, TSB 4309, TSB 4312

1 Check wheel nuts for tightness

– the tightening torque of the wheel nuts must be
checked after the first laden load journey as well
as after each wheel change and, if appropriate,
retightened to the prescribed value –

Tighten wheel nuts diagonally using a torque

wrench to the correct tightening torque.

It is imperative that the prescribed

tightening torques are adhered to in
order to ensure the wheels are securely
fastened!
The wheel studs must be clean and free
of damage and the nuts must be easily
tightened and loosened. If needed, lightly
oil the contact surface between the wheel
nut and the pressure disc. Do not oil or
grease the thread of the wheel studs and
wheel nuts.
Wheel nuts for
Tightening torques for wheel nuts M 22 x 1.5: Stud alignment Spigot alignment
Stud alignment : 510 Nm (485 - 535 Nm)
Spigot alignment: 630 Nm (600 - 660 Nm)

Attention: Do not exceed specified settings!

Wheel contact surface should not have additio-

nal coats of paint (risk of the wheels becoming
detached)!
BPW-W 33111501e Page 43

2 Check brake pad thickness

– quarterly –

The brake pad thickness must be checked regularly,

Trailer axles
e.g. during the tyre inflation pressure check. The
intervals must not be more than 3 months.

The brake pad thickness can be checked where

the brake caliper interfaces with the welded anchor
plate with the wheels mounted (approximate wear
indicator).

Dimension x (distance between brake caliper and

brake anchor plate):
9 mm => when new

TSB 3709 / 4309

30 mm => max. permissible brake
pad wear, 21 mm

34 mm => max. permissible wear for New condition Check required

brake pad and brake disc

TSB 4312
28 mm => max. permissible brake
pad wear, 19 mm

32 mm => max. permissible wear for

brake pad and brake disc

The brake pads must be removed to inspect them

more closely - see relevant workshop manual.

Heat affected, glazed over, or oily brake pads must

be replaced immediately. X X
The remaining brake pad thickness must not be
less than 2 mm (use a caliper gauge for this).

Hairline cracks at the edges are permissible;

replacement is required if more sizable surface
cracks are present. 30 mm

Lining anchor plate

- Visual inspection
– every six months – Brake lining

Check all components and welding seams for da-

mage, wear and corrosion.
2 mm
Brake lining Total brake
thickness lining thickness
Page 44 BPW-W 33111501e

3 BPW Trailer axles / BPW Steering axles

3.2 Maintenance Work and Visual Inspection
3.2.3 Disc brakes, brake types: TSB 3709, TSB 4309, TSB 4312

3 Brake disc
(Check the condition of the brake disc)
– every 6 months when used within Europe,
quarterly when used outside Europe – A B

a
max. 0.75 x a
Sections A - D (see fig.) show the possible condi- max. 1.5 mm
tions of the disc surface:

A: Network-type tears = permissible

B: Radial cracks up to max.

1.5 mm width and depth = permissible
D C

C: Uneven disc surface less

than 1.5 mm = permissible

D: Continuous cracks = not permissible

Technical details:
• Disc thickness, new = 45 mm
• Minimum permissible
disc thickness = 37 mm
(Use a caliper gauge where the pads make
contact)

In the case of surface conditions A - C, the brake

disc can be used until the minimum permissible
disc thickness has been reached.

+ Attention! 45 mm
To prevent damage to the brake discs, the brake 37 mm Wear edge
pads should be replaced when the minimum thick- 30 mm 4 mm
ness (excluding backing plate) is 2 mm or less.

Brake discs should always be replaced in pairs.

The brake pads should also be replaced when 2 mm
new brake discs are fitted.

If this instruction is not adhered to, there is a danger

that with the worn brake pads the brake disc will
be damaged and the braking performance could be
seriously reduced.
BPW-W 33111501e Page 45

4 Checking the brake caliper guide system

(check play and adjustment)
– every 6 months when used within Europe,
quarterly when used outside Europe –

Trailer axles
(e.g. within the scope of the statutory checks)

Prevent the vehicle from rolling away.

Release the service and parking brakes.

The brake cylinder and fasteners for the brake pads

can remain fitted.

Forcefully push the sliding caliper in the axle direc-

tion. The caliper must move approximately 0.7 to
1.3 mm (play).

If play is not within this tolerance, the brake caliper

guide must be checked and readjusted.

For close inspection of play with wheels mounted:

Use a dial gauge to determine the play. To this end,

attach a dial gauge holder to the axle housing and
position the button on the outside of the screw plug
(1) or on the brake cylinder.
20

30

40
10

50
0
90

60
70
80

For close inspection of play with wheels removed:

Check the play using two feeler gauges.

Forcefully push the sliding caliper towards the

centre of the axle and insert the gauges between
the pressure plates (2) and pad backing plate (3).

If play is not within the tolerance required, adjust-

ment must be carried out and the brake caliper
guide checked.
Page 46 BPW-W 33111501e

3 BPW Trailer axles / BPW Steering axles

3.2 Maintenance Work and Visual Inspection
3.2.3 Disc brakes, brake types: TSB 3709, TSB 4309, TSB 4312

Set play and check adjustment

1. Remove the plug.

2. Using a torx wrench (T25), depress the return

spring and turn clockwise until it „clicks“ 2
times.

3. Actuate the brake 5 to 10 times with a force of

approximately 2 bar.

4. Forcefully push the sliding caliper in the axle

direction. The play exhibited at this time must
be between 0.7 and 1.3 mm.
Adjustment is correct if play is within this
tolerance.

5. Reinsert the plug.

Check brake caliper guide: 4

The brake caliper guide must be checked if the play
was not adjusted properly.
1
The guide bushings are sealed by the bellows (4)
and the screw plug (1).

Inspect the bellows and sealing plugs for cracks, da-

mage and proper seating and replace if necessary. 1
Sealing plugs that have been removed must be
replaced, not re-used.

See workshop manual ECO Disc for information on

how to repair the brake caliper guide. 4

Check the brake caliper bearing play:

The bearing play of the brake caliper can be esta-

blished using a dial gauge. Attach the dial gauge
holder to the axle beam and position the gauge,
facing the long locating bearing, on the lower edge
of the cylinder flange.
Press the brake caliper on the brake cylinder
vertically downwards to its installation position
and set the dial gauge to „zero“. Press the brake
caliper upwards and read the bearing play on
the dial gauge. If a brake caliper bearing play ex-
ceeds 1.5 mm, the brake caliper bearing must be
replaced.
BPW-W 33111501e Page 47

5 Check coarse dirt seals and the tappets

– at every brake lining replacement, latest
annually in Europe –
– every six months in use outside Europe –

Trailer axles
Prevent the vehicle from rolling away.
Release the service and parking brakes.

See workshop manual ECO Disc for information on

how to remove the brake pads.

The service brake and spring actuator must be re-

leased.

With a vernier gauge, measure the diameter of the

concentric pin on the two thrust pieces.

When it reaches a minimum of 8 mm, change the

thrust piece.

To change the thrust piece, see workshop manual

ECO Disc. > 30 mm

Unscrew the tappets beyond the adjuster (min.

30 mm) until the coarse dirt seals are plainly visible.

Ensure proper seating.

(Visual inspection, see detail extract)

Check the dust cover of the brake caliper in the

area between the coarse dirt seals (arrows) for
deformation. If deformation is detected, the brake
caliper requires changing!

Note:
Penetrating dirt and damp cause corrosion and
affect the operation of the clamping mechanism
and adjustment.
Page 48 BPW-W 33111501e

3 BPW Trailer axles / BPW Steering axles

3.2 Maintenance Work and Visual Inspection
3.2.3 Disc brakes, brake types: TSB 3709, TSB 4309, TSB 4312

The bellows must be replaced if thermal overloa-

ding was detected.

Only new parts may be used.

The adjustment device must be checked for

corrosion and ease of movement before the new
parts are installed.

See workshop manual ECO Disc for information

on how to replace the bellows.

6 Check the bearing play of the ECO Unit

– at every brake lining replacement, latest annually –

Prevent the vehicle from rolling away.

In order to check the bearing play of the ECO Unit,

lift the axle until the wheels are off the ground. Re-
lease the brake. Apply a lever between the tyre and
the ground and check the play.

The bearing play must be reset if the bearing play

can be felt.

See instructions on setting bearings for ECO Plus 3,

ECO Plus 2 and ECOPlus, pages 33 to 36.
BPW-W 33111501e Page 49

Trailer axles
Page 50 BPW-W 33111501e

3 BPW Trailer axles / BPW Steering axles

3.2 Maintenance Work and Visual Inspection
3.2.4 Disc brakes, brake types: SB 3308, SB 3745, SB 4309, SB 4345

Overview

At every brake lining

2)

latest annually 2)
Every 12 weeks

Every 26 weeks

replacement,
For detailed description, see pages 52 - 62
Disc brakes type TSB, see pages 40 - 48

Initially
Air suspension, see pages 64 - 84
Suspension, see pages 86 - 95
Maintenance work - Disc brake
Brake type: SB 3308, SB 3745, SB 4309, SB 4345
1)
1 Check wheel nuts for firm seating. 1

2 Check brake pad thickness. 2

- Check the tyres for uneven wear, adjust the inflation pressure if necessary -
according to the manufacturer‘s specifications.

Visual check of all components and welding seams for damage, wear and
° °
corrosion.
3)
3 Check brake disc thickness and visually check for cracks. 3 3

3)
4 Check brake adjustment. 4 4

3)
5 Check caliper guide system. 5 5

6 Check bellows on the guide pins.

3)
- ECO Plus 2 and ECOPlus axles 6 6

- ECO axles and axles with conventional hub bearing 6

7 Check caliper unit.

3)
- ECO Plus 2 and ECOPlus axles 7 7

- ECO axles and axles with conventional hub bearing 7

8 Check wheel hub bearing play, adjust if necessary.

- ECO Plus 2 and ECOPlus Unit 8

- ECO Unit and conventional hub bearing 8

9 Check caps for tightness. (not necessary with ECO Plus 2 and ECOPlus axles) 9

1) After the first run under load conditions, likewise after each wheel change.
2) Under extreme conditions, increase frequency (eg. construction sites and poor roads).
3) For use outside Europe.

Note: Components that have damage due to improper mounting are to be exchanged after a review by a BPW
Service Centre.
BPW-W 33111501e Page 51

9 8 1 2 3 6 5 4 7

Trailer axles
5
Series SH / SKH with disc brakes type SB

Series SH..LL / SKH..LL with disc brakes type SB

Series SNR with disc brakes type SB

Page 52 BPW-W 33111501e

3 BPW Trailer axles / BPW Steering axles

3.2 Maintenance Work and Visual Inspection
3.2.4 Disc brakes, brake types: SB 3308, SB 3745, SB 4309, SB 4345

1 Check wheel nuts for tightness

– the tightening torque of the wheel nuts must be
checked after the first laden load journey as well
as after each wheel change and, if appropriate,
retightened to the prescribed value –

Tighten wheel nuts diagonally using a torque

wrench to the correct tightening torque.

It is imperative that the prescribed tighte-

ning torques are adhered to in order to
ensure the wheels are securely fastened!
The wheel studs must be clean and free
of damage and the nuts must be easily
tightened and loosened. If needed, lightly
oil the contact surface between the wheel
nut and the pressure disc. Do not oil or
grease the thread of the wheel studs and
wheel nuts.
Tightening torques for wheel nuts: Wheel nuts for

M 18 x 1.5 Stud alignment Spigot alignment

Stud alignment: 290 Nm (275 - 305 Nm)
Spigot alignment: 350 Nm (330 - 370 Nm)

M 22 x 1.5:
Stud alignment: 510 Nm (485 - 535 Nm)
Spigot alignment: 630 Nm (600 - 660 Nm)

Attention: Do not exceed specified settings!

Wheel contact surface should not have additional
coats of paint (risk of the wheels becoming
detached)!
BPW-W 33111501e Page 53

2 Check brake pad thickness

30 mm
SB 3745 / SB 4309 / SB 4345
– quarterly – Lining anchor plate

Trailer axles
The brake pad thickness must be checked regularly,
e.g. during the tyre inflation pressure check. The
intervals must not be more than 3 months. Brake lining

The thickness of the remaining pad must not be

less than 2 mm (check with slide gauge).
2 mm
Brake lining Total brake
thickness lining thickness

+ Open bearing: New condition Check brake pad

tickness
The thickness of the brake pad can be checked by
the position of the brake caliper (1) in relation to the
guide rod (2) (approximate indication of wear) with
the wheels attached.

If the end of the guide sleeve (3) is level with the 3

fixed guide rod, the pad thickness must be checked
again after the wheels have been removed.

2 1

+ Sealed bearing: New condition Check brake pad

thickness
The sealed bearing has a ridged rubber seal which
is fitted over the guide pin. Pad wear should be
checked when the wear mark (transition point
between the ridged and smooth areas - see
diagram) has moved to the end of the guide pin.
Page 54 BPW-W 33111501e

3 BPW Trailer axles / BPW Steering axles

3.2 Maintenance Work and Visual Inspection
3.2.4 Disc brakes, brake types: SB 3308, SB 3745, SB 4309, SB 4345

Check brake pad thickness

SB 3308
– quarterly – Brake anchor plate

The brake pad thickness must be checked regularly,

e.g. during the tyre inflation pressure check. The
Brake lining
intervals must not be more than 3 months.

The thickness of the remaining pad must not be

less than 2 mm (check with slide gauge).

2 mm
Brake lining Total brake
thickness lining thickness

The brake pad thickness can be checked with the

wheels attached by means of the position of the
brake caliper marking (P) in relation to the fixed brake
carrier flange (R).
P
On reaching the status as shown in the illustration
below right, the brake pad thickness and the brake
disc must be checked with the wheel removed.

Replace the brake pads and/or brake disc as

necessary.
R

New condition

A brake pad and brake disc check is

necessary
BPW-W 33111501e Page 55

- Check the tyres for uneven wear and adjust the

inflation pressure if necessary according to the
manufacturer’s specifications A B

a
max. 0.75 x a
– quarterly –

Trailer axles
max. 1.5 mm

° Visual inspection
– every six months – D C
Check all components and welding seams for da-
mage, wear and corrosion.

3 Brake disc
(Check the condition of the brake disc)
– every 6 months –
– quarterly in use outside Europe –

Section A - D (see fig.) show the possible condi-

tions of the disc surface:

A: Network-type tears = permissible

B: Radial cracks
up to max. 1.5 mm
width and depth = permissible

C: Uneven disc surface less

than 1.5 mm = permissible

D: Continuous cracks = not permissible

In the case of surface conditions A - C the brake

disc can be used until the minimum permissible
disc thickness has been reached.

+ Attention!
To prevent damage to the brake discs, the brake
pads should be replaced when their thickness
(excluding backing plate) is 2 mm or less.

If this instruction is not adhered to, there is a danger

that with the worn brake pads the brake disc will
be damaged and the braking performance could be
seriously reduced.
Page 56 BPW-W 33111501e

3 BPW Trailer axles / BPW Steering axles

3.2 Maintenance Work and Visual Inspection
3.2.4 Disc brakes, brake types: SB 3308, SB 3745, SB 4309, SB 4345

SB 3745 / SB 4309 / SB 4345

45 mm
Technical details: 37 mm Wear edge
• Disc thickness, new = 45 mm 30 mm 4 mm
• Minimum permissible disc
thickness = 37 mm
(check with slide gauge)
2 mm

SB 3308
A Wear edge
Technical details:
C1 C2
A Disc thickness, new = 34 mm

minimum permissible disc = 28 mm

thickness (check with slide
gauge) D1 D2

C1 Overall thickness of new E E

brake pad = 27 mm

C2 Overall thickness of F1 F2
new brake pad = 34 mm

D1 Pad backing plate = 8 mm

D2 Pad backing plate = 15 mm

E Brake pad minimum thickness = 2 mm

F1 Brake pad minimum thickness

incl. pad backing plate = 10 mm

F2 Brake pad minimum thickness

incl. pad backing plate = 17 mm
BPW-W 33111501e Page 57

4 Check adjustment
– every 6 months –
– quarterly in use outside Europe –

Trailer axles
Prevent the vehicle from rolling away.
Release the service brakes and the handbrake.

SB 3308
Remove wheel. Remove pad retainer clip. Pull the
brake caliper on its guide pins in the direction of the
outside of the vehicle.

Using a suitable tool, press the outer brake pad in

the direction of the tappet. Measure the gap bet-
ween the backing plate and the inside of the caliper.
This must be between 0.6 and 1.1 mm.

+ Attention!
If the air gap is too large, the braking effect may fail.
If the air gap is too small, brake may overheat and
cause further damage.

If the air gap is to big or too small, the adjustment

must be checked as follows:

SB 3308 / SB 3745 / SB 4309 / SB 4345

Remove cap.
Place a ring spanner size 8 on the hex. profile of
the adjuster, or a spanner size 10 on the adjuster
adapter. Turn anti-clockwise until the ratchet clicks
3 or 4 times.

+ Attention!
If the version has an adjustment adapter, never turn
without the adapter. Exceeding the specified break-
off torque of the adapter will cause the adapter to
break.
Repeat with a new adapter. Fit a new brake caliper
if the adapter shears off again - this is an indication
of internal damage.

Do not use an open-ended spanner.

Max. torque: approx. 25 Nm

Page 58 BPW-W 33111501e

3 BPW Trailer axles / BPW Steering axles

3.2 Maintenance Work and Visual Inspection
3.2.4 Disc brakes, brake types: SB 3308, SB 3745, SB 4309, SB 4345

Apply brake 5 to 10 times (approximately 2 bar). If

the adjustment is correct, the ring spanner will turn
back in a clockwise direction (make sure the ring
spanner can rotate freely).

Note: As the cycle rate increases, the movement of

the ring spanner, becomes smaller.

If the ring spanner moves as described, the adjust-

ment is then OK.

Remove ring spanner.

Apply Renolit HLT2 to the cap and re-fit. For the

version with the adapter, fit the lug on the cap poin-
ting towards the axle beam.

The adjuster or the ring spanner:

a) does not turn,
b) turns only upon initial application,
c) turns forward and back again upon each
application,

the adjustment is not correct and the brake caliper

must be replaced.
BPW-W 33111501e Page 59

5 Check the brake caliper guide system 2 1 1a 4 3

– every 6 months –
(e.g. within the scope of the statutory checks)
– quarterly in use outside Europe –

Trailer axles
Prevent the vehicle from rolling away.
Release the service brakes and the handbrake.

Apply considerable pressure to the sliding caliper

in the direction of the guide bearing. It should be
possible to move it by about 0.5 to 1 mm (play).
Check the brake caliper guide if this is not the case.

SB 3745 / SB 4309 / SB 4345

The guide bush (1a) is sealed by the bellows (2) and
the sheet metal cap (3) with the sealing ring (4).

Parts (2) and (3) must not be split or damaged in any

way. If necessary, replace. Check for correct fitting.

If the version has a guide sleeve (5), check it for

damage and to make sure it is correctly seated.

1 1a 5
SB 3308
Ability of the caliper to slide to the full extent of the 7 13 9 8
caliper guides:

Remove the brake pads. Fully retract the tappet (7)

by turning the adjuster in an anti-clockwise direc-
12
tion, using an adapter.

It must be possible to slide the brake caliper (6) by

hand over the entire distance of more than 20 mm
on the guide pieces (8) and (9) as well as (10) and
(11), without using any tools.

Check caliper guide seals:

The guide bushes (8) and (10) are sealed by means

of the bellows pieces (12) and (13). These parts
must not show any cracks or damage. Check that
everything is properly seated.
12

6 13 11 10
Page 60 BPW-W 33111501e

3 BPW Trailer axles / BPW Steering axles

3.2 Maintenance Work and Visual Inspection
3.2.4 Disc brakes, brake types: SB 3308, SB 3745, SB 4309, SB 4345

6 Bellows at the thrust pieces

– ECO Plus 2 and ECOPlus axles, when used within
Europe, at every brake pad change or every year
at the latest; every six months outside Europe –
– ECO axles and axles with conventional mounting,
every six months –

Prevent the vehicle from rolling away.

Release the service brakes and the handbrake.

Remove the brake pads, if necessary.

The service brake and the spring-loaded parking

brake must be in the released state.

Use the adjuster to extend the tappet,

SB 3745 / SB 4309 / SB 4345 max. 30 mm,
SB 3308 max. 40 mm,
until the bellows seal is clearly visible.

The bellows on the tappets (arrow) must have no

splits or damage.

Check for correct fitting.

Note: Penetrating dirt and moisture cause cor-

rosion and affect the operation of the clamping
mechanism and adjustment.

If water has penetrated or rusting has been detec-

ted, replace the brake caliper.
max
. 40

SB 3308
BPW-W 33111501e Page 61

7 Check the caliper

– ECO Plus 2 and ECOPlus axles, when used within
Europe, at every brake pad change or every year
at the latest; every six months outside Europe –
1

Trailer axles
– ECO axles and axles with conventional mounting, 3
every six months –
If damage to the parts becomes visible on the thrust 2
tappet when the bellows are checked, both bellows
must be dismantled. The parts which have been
removed must be replaced by new ones.

Before the new parts are fitted, check that the adjus-
ting unit is free of corrosion and operates smoothly.

To check the parts, turn the threaded tubes (1)

(SB 3308 a threaded pipe) on the hexagon nut (size
8 or size 10 with an adapter) of the adjuster clock-
wise onto the brake disc (2).

The threads of the threaded tubes (1) can be checked

during the turning process for corrosion damage.

If the threads are rusted, the brake caliper must be

replaced.

+ Note:
To prevent the threaded tubes (1) from being turned
completely out of the caliper, insert a new brake
pad (3) into the caliper in the outboard brake pad
position.

+ To prevent the threaded tubes from being wound

completely out of the caliper when working on a
work bench, insert a separator (4) (approx. 75 mm,
in the case of SB 3308, approx. 60 mm) between
the tubes and the caliper housing.
If the threaded tubes are wound completely out
of the caliper, the brake caliper must be replaced.

1 4
Page 62 BPW-W 33111501e

3 BPW Trailer axles / BPW Steering axles

3.2 Maintenance Work and Visual Inspection
3.2.4 Disc brakes, brake types: SB 3308, SB 3745, SB 4309, SB 4345

8 Check wheel hub bearing play

– ECO Plus 2 and ECOPlus Unit at every brake pad
change, however at least once a year –

– ECO Unit and conventional hub bearing every

six months –

To check the wheel hub bearing play, raise the axle

until the tyres are free. Release brake. Position lever
between tyre and ground, and check play.

If you can feel play in the bearing, adjust the

bearing play as described on pages 34 - 38.

9 Check caps for tightness

(not necessary with ECO Plus 2 and ECOPlus axles)
– every 6 months and/ or as part of any other
service inspection –

Check caps for tightness using a torque wrench or

power tool.

Tightening torques:
Steel cap 5.5 t M = 500 Nm
6 - 12 t M = 800 Nm
Alloy cap M = 350 Nm

In an emergency the caps can be tightened using

a normal cap spanner (vehicle tool kit) by striking
the latter with a hammer, or also with the aid of
a piece of tubing, inserted into the spanner.
Caps with integrated hubodometers must be fitted
and dismantled using only torque controlled (do not
use air impact wrenches) airguns or manually with a
torque wrench. Position 1 Position 2

Tighten to the correct tightening torque as soon

as possible.

+ Note:
Caps on ECO Plus 2 axles are provided with a
bayonet fitting. Check for firm seating.

Position 1: Hub cap seated loosely on the Unit.

Position 2: Hub cap seated firmly on the Unit.

BPW-W 33111501e Page 63

Trailer axles
Page 64 BPW-W 33111501e

4 BPW Air suspension, series EAC

4.1 Overview, Lubrication and Maintenance Work, Visual Inspection

Overview

suspension after 12, 36, 60

warranty period for chassis
Visual checks during the

fitted with ECO Plus air

subsequently yearly
and 72 months,
For detailed description, see pages 66 - 71
Air suspension series O, SL, AL see pages 72 - 84
Suspension, see pages 86 - 95

1 Check air suspension levelling valve for condition, seal-tightness and general tightness. 1

2 Check condition of air bags. 2

- Visual inspection, check all component parts and welding seams for damage and wear. -

3 Check shock absorber fastening for tightness. 3

Tightening torque with a torque wrench:
M 24 (SW 36) M = 420 Nm (390 - 460 Nm)

4 Check spring pivot bolts for tightness. 4

Tightening torque with a torque wrench:
M 24 (SW 36) M = 650 Nm (605 - 715 Nm)

5 Check axle clamping for tightness. 5

Tightening torque with a torque wrench:
M 20 (SW 30) M = 420 Nm

6 Check the spring bolt to gusset plate connecting bolt for tightness. 6
Tightening torques with a torque wrench:
M 18 x 1.5 (SW 27) M = 420 Nm (390 - 460 Nm)

7 Check air bag fastening for tightness. 7

Tightening torques with a torque wrench:
M 12 (SW 17) M = 66 Nm
M 16 (SW 22) M = 230 - 300 Nm
Centre screw M 16 (SW 22) M = 300 Nm

8 Check axle lift for tightness. 8

Tightening torques with a torque wrench:
Supporting arm M 20 (SW 30) M = 350 Nm (325 - 385 Nm)
Diaphragm cylinder M 16 (SW 24) M = 190 Nm (180 - 210 Nm)
Hexagon screw M 12 (SW 17) M = 75 Nm
Cylinder cap screw M 10 (SW 8) M = 50 Nm

Note:
Components that have damage due to improper mounting are to be exchanged after a review by a
BPW Service Centre.
BPW-W 33111501e Page 65

4 3 1 2 7 2

5 7 7
Serie ACBO Serie ACBO with Kombi-Air Bag II

Air suspension
4 3 1 7 2

8 5 7 6
Series ACAM / ACBM Serie ACBM with bolt-on gusset plate
with two-sided axle lift

4 3 1 7 2 2

5 7 7 8
Series ACAU Serie ACAM with side mounted axle lift
Page 66 BPW-W 33111501e

4 BPW Air suspension, series EAC

4.2 Maintenance Work and Visual Inspection

1 Air installation circuit

– Service intervals as shown on page 64 –

Check air installation valves and line connections

for firm seating, damage and seal tightness. 1
Check valve linkage and fastenings (arrows) for
damage and tightness.

The length of the valve lever and permissible

angular positions for the valve linkage are shown in
the illustration below.

Air suspension valve

Frame attachment min. 200

EF
>0
°

Valve lever
<
90

Ride height
°

Guide rod
AF <

Axle travel down Axle travel up

180
°

EF

Guide linkage
AF

DIRECTION OF TRAVEL
BPW-W 33111501e Page 67

2 Air bags
– Service intervals as shown on page 64 –
2

Check air bags for external damage (surface cra-

cking, abrasion, crease formation, trapped foreign
bodies etc.). Replace air bags in the event of da-
mage.

Safety notice
No welding should be carried out on steel parts
of air bags and pressure vessel!

The air suspension should only be filled with com-

pressed air when mounted.

Air suspension
Danger of injury!

- Visual inspection
– Service intervals as shown on page 64 –

Check all component parts and welding seams for

wear and damage.

3 Shock absorber fastening

– Service intervals as shown on page 64 –

Check lower and upper shock absorber fastening

for tightness.

Tightening torques with a torque wrench:

M 24 (SW 36) M = 420 Nm (390 - 460 Nm)

3
Page 68 BPW-W 33111501e

4 BPW Air suspension, series EAC

4.2 Maintenance Work and Visual Inspection

4 Spring pivot bolts

– Service intervals as shown on page 64 –

Check bushes; move vehicle back and forth slightly

with brakes applied or move spring eyes with as-
sembly lever with brakes released. No play should
be present in the rolled spring end when doing so. 4
If the fastening is loose the spring pivot bolt may be
damaged.

- Check the lateral wear washers in the hanger

bracket.

- Check the M 24 lock nut on the spring pivot

bolt for tightness.

Tightening torque with a torque wrench:

M 24 (SW 36) M = 650 Nm (605 - 715 Nm)

The life expectancy of the bearing depends on the Adjustment Adjustment

tightness of the spring bolt or the inner bush. plates plates

Head of spring pivot bolt

in adjustment plates
Spring pivot bolt

Washer

Lateral
wear washers

5 Axle clamping
– Service intervals as shown on page 64 –

Check lock nuts of spring U-bolts for tightness. If

loose, tighten nuts alternately a little at a time.

Tightening torques with a torque wrench:

M 20 (SW 30) M = 420 Nm

When mounting new spring mounting kit compo-

nents, tighten the M 20 locknuts to a tightening 5
torque of: M = 420 Nm + 90° angle tightening.

+ Note: Do not weld on the trailing arms and the

bellows support!
BPW-W 33111501e Page 69

6 Bolted connection, gusset plate spring bolts

– Service intervals as shown on page 64 –

Check the mounting bolts of the gusset plates on

the spring bolts are firmly tightened, and retighten
with a torque wrench if necessary.

Tightening torque:
M 18 (SW 27) M = 420 Nm (390 - 460 Nm)
6

Installing or renewing the spring bolt:

1. Unscrew or install the spring bolt.

2. Loosely pre-mount the gusset plate with at least

Air suspension
three M 16 bolts at the top on the crossmember
and one M 18 bolt at the bottom on the spring
bolt and tighten further until contact is made.

3. Set the track.

4. Tighten the spring bolt to the prescribed tighte-

ning torque.

5. Tighten the connecting bolt on the gusset

plates spring bolt and then tighten the upper
connecting bolt to the prescribed tightening
torques.

7 Air bag fastenings

– Service intervals as shown on page 64 –

Check air bag fixing bolts or nuts for tightness. 7

If necessary, retighten.

Tightening torques with a torque wrench:

M 12 (SW 17) M = 66 Nm
M 16 (SW 22) M = 200 - 230 Nm

Lower attachment - centre screw:

M 16 (SW 22) M = 300 Nm

7
Page 70 BPW-W 33111501e

4 BPW Air suspension, series EAC

4.2 Maintenance Work and Visual Inspection

8 Axle lift
– Service intervals as shown on page 64 –

Sidewise mounted axle lift:

Check for tight fitting of the M 20 lock nut of the

roller mounting on the lifting arm, if necessary
tighten with a torque wrench.

Tightening torque:
M 20 (SW 30) M = 350 Nm (325 - 385 Nm)

7 4 8

Two-sided lift:
8d
a) Check the M 16 lock nuts on the diaphragm 8b
cylinder to make sure they are tight. Tighten
with a torque wrench if necessary.
Tightening torque:
M 16 (SW 24) M = 190 Nm (180 - 210 Nm)

b) Check for tight seating of the bump stop fixing

screws on the trailing arms. 8c
Tightening torque:
M 10 (SW 8) M = 50 Nm 8a

c) Check for tight seating of the bracket fixing

screws on the shaped plate.
Tightening torque:
M 12 (SW 17) M = 75 Nm

d) Check for the correct seating of the bolt circlip

on the rear attachment support of the air
suspension hanger brackets.
BPW-W 33111501e Page 71

Spring pivot bolt bearing with axle lift

Side mounted axle lift Two-sided lift

Spring bolt Adjusting plate with

anti-rotation device

Shaped
Adjusting plate part

Bush

Air suspension
Locking disc
Bush

Bolt
Bush

Shaped plate

Tube

Support

Lever

Cylinder
Page 72 BPW-W 33111501e

5 BPW Air suspension, series O, SL, AL

5.1 Overview, Lubrication and Maintenance Work, Visual Inspection

Overview

after 12, 36, 60 and 72 months.

Within 2 weeks of first journey

Visual checks during the war-

with ECO Plus air suspension

ranty period for chassis fitted
latest after 2000 km 1)
For detailed description, see pages 76 - 84

under load,

Annually 2)
Air suspension series EAC see pages 64 - 71
Suspension, see pages 86 - 95

3)
1 Grease stabilizer bearing bushes with BPW special longlife grease ECO-LiPlus 1 1
and check for wear.
3)
- Visual inspection, check all component parts and welding seams for damage - -
and wear.

1 Check strap: Check condition and fastening. 1 1

2 Check air suspension levelling valve for condition, seal-tightness and general 2 2
tightness.

3 Check condition of air bags. 3 3

4 Check shock absorber fastening for tightness. 4 4 4

Tightening torque with a torque wrench:
M 20 (SW 30) M = 320 Nm (300 - 350 Nm)
M 24 (SW 36) M = 420 Nm (390 - 460 Nm)
For aluminium hanger brackets:
M 24 (SW 36) M = 320 Nm (300 - 350 Nm)

5 Check spring pivot bolts for tightness. 5 5 5

Tightening torque with a torque wrench:
Hanger brackets and channel crossmember Airlight II from 09/2007:
M 24 (SW 36) M = 650 Nm (605 - 715 Nm)
Hanger brackets from 8/2001:
M 30 (SW 46) M = 900 Nm (840 - 990 Nm)
Hanger brackets up to 7/2001:
M 30 (SW 46) M = 750 Nm (700 - 825 Nm)
Channel crossmember:
M 30 (SW 46) M = 900 Nm (840 - 990 Nm)

6 Check spring mounting kit for tightness. 6 6 6

Tightening torque with a torque wrench:
M 20 (SW 30) M = 340 Nm (315 - 375 Nm)
M 22 (SW 32) M = 550 Nm (510 - 605 Nm)
M 24 (SW 36) M = 650 Nm (605 - 715 Nm)
When mounting new spring mounting kits for Airlight II:
M 22 (SW 32) M = 550 Nm + 90° angle tightening

1) ECO Plus Units with Airlight II and Airlight Direct air suspension are maintenance-free in On-Road applications and do not need to be
retightened (see warranty documents ECO Plus).
2) Under extreme conditions, with more frequency.
3) Check twice annually.
BPW-W 33111501e Page 73

5 4 6 2 3 5 1

Series ALO/SLO Series ALO/SLO

Air suspension
with two-sided axle lift

5 3

5
Series ALM/SLM with Kombi-Air Bag II Series ALM/SLM with bolted-on
air suspension hanger bracket

3 3

5
Series ALU/SLU with Series DLU - Airlight Direct
sidewise mounted axle lift
Page 74 BPW-W 33111501e

5 BPW Air suspension, series O, SL, AL

5.1 Overview, Lubrication and Maintenance Work, Visual Inspection

Overview

after 12, 36, 60 and 72 months.

Within 2 weeks of first journey

Visual checks during the war-

with ECO Plus air suspension

ranty period for chassis fitted
latest after 2000 km 1)
under load,

Annually 2)
For detailed description, see pages 76 - 84
Air suspension series EAC see pages 64 - 71
Suspension, see pages 86 - 95

7 Check the bolt connection between the air suspension hanger bracket and the 7 7 7
longitudinal member for tightness.
Tightening torques with a torque wrench:
M 16 M = 260 Nm (240 - 285 Nm)
8 Tighten the spring bolt to gusset plate connecting bolt. 8 8 8
Tightening torques with a torque wrench:
M 18 x 1.5 (SW 27) M = 420 Nm (390 - 460 Nm)

9 Check axle lift for tightness. 9 9 9

Tightening torques with a torque wrench:
Cylinder
M 20 (SW 30) M = 350 - 380 Nm
M 16 (SW 24) M = 180 - 210 Nm
Supporting arm
M 16 (SW 22) M = 230 Nm
Hexagon screw
M 12 (SW 17) M = 75 Nm

10 Check air bag fastening for tightness. 10 10 10

Tightening torques with a torque wrench:
M 12 (SW 17) M = 66 Nm
M 16 (SW 22) M = 230 - 300 Nm
Lower attachment - centre screw
M 16 (SW 22) M = 300 Nm

11 Check stabilizer fastenings. 11 11 11

Tightening torques with a torque wrench:
M 10 (SW 17) M = 53 Nm
M 30 (SW 46) M = 750 Nm (700 - 825 Nm)

1) ECO Plus Units with Airlight II and Airlight Direct air suspension are maintenance-free in On-Road applications and do not need to be
retightened (see warranty documents ECO Plus).
2) Under extreme conditions, with more frequency.

Note:
Components that have damage due to improper mounting are to be exchanged after a review by a BPW Service Centre.
BPW-W 33111501e Page 75

10 9
Series ALO/SLO Series ALO/SLO

Air suspension
with two-sided axle lift

10 8 9
Series ALM/SLM Series ALM/SLM with bolted-on air
with Kombi-Air Bag II suspension hanger bracket and bolt-on
double-sided lift

10 10

10 9
Series ALU/SLU Series DLU - Airlight Direct
with sidewise mounted axle lift
Page 76 BPW-W 33111501e

5 BPW Air suspension, series O, SL, AL

5.2 Lubrication
5.3 Maintenance Work and Visual Inspection
1 Stabilizer bearing bushes
– Service intervals as shown on page 72 –

Grease stabilizer bearing bushes with BPW special

longlife grease ECO-LiPlus and check for wear.
1

- Visual inspection
– Service intervals as shown on page 72 –

Check all component parts and welding seams for

wear and damage.

1 Check straps
– Service intervals as shown on page 72 –

Examine check straps and attachment. Replace if

necessary. 1
BPW-W 33111501e Page 77

2 Air installation circuit

– Service intervals as shown on page 72 –

Check air installation valves and line connections

for firm seating, damage and seal tightness. 2
Check valve linkage and fastenings (arrows) for
damage and tightness.

The length of the valve lever and permissible

angular positions for the valve linkage are shown in
the illustration below.

Air suspension
Air suspension valve

Frame attachment min. 200

EF
>0
°

Valve lever
<
90

Ride height
°

Guide rod
AF <

Axle travel down Axle travel up

180
°

EF

Guide linkage
AF

DIRECTION OF TRAVEL
Page 78 BPW-W 33111501e

5 BPW Air suspension, series O, SL, AL

5.3 Maintenance Work and Visual Inspection

3 Air bags
– Service intervals as shown on page 72 –

Check air bags for external damage (surface cra-

cking, abrasion, crease formation, trapped for-
eign bodies etc.). Replace air bags in the event of
damage.

Safety notice
No welding should be carried out on steel parts 3
of air bags and pressure vessel!

The air suspension should only be filled with com-

pressed air when mounted.
Danger of injury!

4 Shock absorber fastening

– Service intervals as shown on page 72 – 4
Check lower and upper shock absorber fastening for
tightness. Tightening torques with a torque wrench.

Tightening torque:
M 20 (SW 30) M = 320 Nm (300 - 350 Nm)
M 24 (SW 36) M = 420 Nm (390 - 460 Nm)
In the case of alloy hanger brackets:
M 24 (SW 36) M = 320 Nm (300 - 350 Nm)
BPW-W 33111501e Page 79

5 Spring pivot bolts

– Service intervals as shown on page 72 –

Check bushes, move vehicle back and forth

slightly with the brake applied, or move rolled
spring ends with the aid of a lever. No play should
be present in the rolled spring end when doing so.
If the fastening is loose the spring pivot bolt may be
damaged.

- Check the lateral wear washers in the hanger

bracket.
5
- Check the M 24 or M 30 lock nut on the spring
pivot bolt for tightness.

Air suspension
Tightening torque with a torque wrench:

Air suspension hanger brackets and channel Non-adjustable hanger bracket

crossmember from 09/2007:
M 24 (SW 36) M = 650 Nm (605 - 715 Nm)

Head of spring pivot bolt

held in square locator
Hanger brackets from 08/2001:
M 30 (SW 46) M = 900 Nm (840 - 990 Nm)

Hanger brackets up to 07/2001: Spring pivot bolt

M 30 (SW 46) M = 750 Nm (700 - 825 Nm)

Channel crossmember:
M 30 (SW 46) M = 900 Nm (840 - 990 Nm)
Lateral
wear washers
The serviceable life of the rubber / steel bush is de-
pendent on the tightness of the inner steel bushing.

Adjustable hanger bracket

Adjustment Adjustment
plates plates
Head of spring pivot bolt
in adjustment plates

Spring pivot bolt

Washer
Lateral
wear washers
Page 80 BPW-W 33111501e

5 BPW Air suspension, series O, SL, AL

5.3 Maintenance Work and Visual Inspection

6 Spring mounting kit

– Service intervals as shown on page 72 –
6

Check lock nuts of spring U-bolts for tightness. If

loose, tighten nuts alternately a little at a time.

Tightening torques with a torque wrench:

M 20 (SW 30) M = 340 Nm (315 - 375 Nm)
M 22 (SW 32) M = 550 Nm (510 - 605 Nm)
M 24 (SW 36) M = 650 Nm (605 - 715 Nm)

When mounting new spring mounting kit compo-

nents for Airlight II, tighten the M 22 locknuts to a
tightening torque of:
M = 550 Nm + 90° angle tightening.

+ Note: No welding should be performed on the

trailing arm spring!

7 Bolted connection, air suspension hanger bracket to

longitudinal chassis beam 7
– Service intervals as shown on page 74 –

Check that the mounting bolts of the air suspen-

sion hanger bracket on the longitudinal member
are firmly tightened.
Tighten with a torque wrench if necessary.

Tightening torque:
M 16 M = 260 Nm (240 - 285 Nm)
BPW-W 33111501e Page 81

8 Bolted connection, gusset plate spring bolts

– Service intervals as shown on page 74 –

Check the mounting bolts of the gusset plates on

the spring bolts are firmly tightened, and retighten
with a torque wrench if necessary.

Tightening torque:
M 18 x 1.5 (SW 27) M = 420 Nm (390 - 460 Nm)
8

Installing or renewing the spring bolt:

1. Unscrew or install the spring bolt.

2. Loosely pre-mount the gusset plate with at

Air suspension
least three M 16 bolts at the top on the cross-
member and one M 18 bolt at the bottom on
the spring bolt and tighten further until contact
is made.

3. Set the track.

4. Tighten the spring bolt to the prescribed tighte-

ning torque.

5. Tighten the connecting bolt on the gusset

plates spring bolt and then tighten the upper
connecting bolt to the prescribed tightening
torques.
Page 82 BPW-W 33111501e

5 BPW Air suspension, series O, SL, AL

5.3 Maintenance Work and Visual Inspection

9 Axle lift
– Service intervals as shown on page 74 –

Single-sided lift

Check the M16 lock nuts on the lever arm fixing 5

to make sure they are tight. Tighten with a torque
wrench if necessary.
Tightening torque:
M 16 (SW 22) M = 230 Nm

Check for wear on the bump stop on the lever arm. 10

Make sure it is secure. 9 9
Tightening torque: Single-sided lift
M 10 (SW 17) M = 25 Nm
M 12 (SW 17) M = 66 Nm

Two-sided lift:
5
a) Check the M 16 lock nuts on the diaphragm
cylinder to make sure they are tight. Tighten
with a torque wrench if necessary.
9c
Tightening torque:
M 20 (SW 30) M = 350 - 380 Nm
M 16 (SW 24) M = 180 - 210 Nm
9b

b) Check the bump stop on the lever arm for wear,

9a
and that the M 6 attachment bolts are firmly
tightened.

Two-sided lift
c) Check that the attachment bolts of the front
bracing strut of the mount on the air suspension
hanger bracket are tight, and in the case of the
bolt-on two-sided lift, the bolted connection on
the air suspension hanger bracket. 5
Tightening torque:
M 12 (SW 17) M = 75 Nm

9c 9b

9a

Bolt-on double-sided lift

BPW-W 33111501e Page 83

Spring pivot bolt bearing with axle lift

Single-sided lift Two-sided lift

Turnproof device
Spring pivot bolt
Spring pivot bolt

Air suspension
Washer

Bolt-on two - sided lift

Spring pivot bolt

Screws
M 12

Support

Lever
Page 84 BPW-W 33111501e

5 BPW Air suspension, series O, SL, AL

5.3 Maintenance Work and Visual Inspection

10 Air bag fastenings

– Service intervals as shown on page 74 –

Check air bag fixing bolts or nuts for tightness. 10

If necessary retighten using torque wrench.

Tightening torques with a torque wrench:

M 12 (SW 17) M = 66 Nm
10
M 16 (SW 22) M = 230 - 300 Nm

Lower attachment - centre screw

M 16 (SW 22) M = 300 Nm

11 Stabilizer
– Service intervals as shown on page 74 –

Check stabilizer bearings for wear and tightness. 11

Tightening torques with a torque wrench: 11

M 10 (SW 17) M = 53 Nm
M 30 (SW 46) M = 750 Nm (700 - 825 Nm) 11
BPW-W 33111501e Page 85

Air suspension
Page 86 BPW-W 33111501e

6 BPW Suspension, series ECO Cargo VB

6.1 Overview, Lubrication and Maintenance Work, Visual Inspection

Overview

1)
Every 26 weeks
(twice annually)
Every 6 weeks
after 2 weeks
Initially
For detailed descriptions, see pages 88 - 91
For BPW trailer axles / steering axles, see pages 6 - 62
1) 1)
1 Grease bearings (suspension type E) with BPW special longlife grease ECO-LiPlus.
(Not applicable in the case of rubber/steel bushes.)

2 Slightly grease the slide elements/slide ends of springs.

1 Check threaded bolts on equaliser arm bearings for tightness.

up to an axle load of 12 tonnes (from 08/2013)
M 42 x 3 (SW 65) M = 1300 Nm
up to an axle load of 12 tonnes (up to 07/ 2013)
M 42 x 3 (SW 65) M = 1100 Nm
Series HD / HDE M 48 x 3 (SW 65) M = 1200 - 1300 Nm

2 Check axle connecting rod bolts for tightness using a torque wrench.
M 24 x 2 (SW 36) M = 650 Nm
M 30 (SW 46) M = 725 Nm
M 36 (SW 55) M = 1425 Nm

3 Check connecting rod clamping bolts for tightness.

M 12 (SW 19) M = 66 Nm
M 14 (SW 22) M = 140 Nm

4 Check spring U-bolts for tightness using a torque wrench.

M 24 (SW 36) M = 600 - 650 Nm

- Visual inspection, check all component parts and welding seams for wear and damage.

5 Check slide elements for tightness.

M 14 (SW 22) M = 140 Nm
M 20 (SW 30) M = 320 Nm
1) Under extreme conditions, with more frequency.

Note:
Components that have damage due to improper mounting are to be exchanged after a review by a
BPW Service Centre.
BPW-W 33111501e Page 87

5 5 1 1 2 4 2

2 2
Series ECO Cargo VB ...M ...ME

5 5 1 1 2 4 2

ECO Cargo VB / VB HD
2 3 2
Series ECO Cargo VB HD / HDE
Page 88 BPW-W 33111501e

6 BPW Suspension, series ECO Cargo VB

6.2 Lubrication

1 Equalizer arm bearings with bronze bushes

(Series ECO Cargo VB ME and ECO Cargo VB HDE) 1
– initially after 2 weeks then every 6 weeks –
– under extreme conditions, lubricate with more
frequency –

Lift trailer to take pressure off equalizer arm

bearings.

Grease bronze bush bearing via the grease nipple

in the heads of the threaded bolts with BPW special
longlife grease ECO-LiPlus until fresh grease emer-
ges. (Not applicable to rubber/steel bushes.)

At extremely low temperatures (-30° C to -50° C)

a grease with correspondingly lower consistency
class should be used - such as BPW ECO-Li Polar.

2 Slide elements
– initially after 2 weeks then every 6 weeks – 2
– under extreme conditions, lubricate with more
2
frequency –

Clean and lightly grease the slides / slide ends of

the springs.
In the case of ECO Cargo VB suspensions (up to
07/2013) with anti-vibration leaf underneath the
parabolic springs, grease the lower slide elements
via the grease nipples (arrow).
BPW-W 33111501e Page 89

Maintenance Work and Visual Inspection 6.3

1 Equalizer arm bearings

– twice annually –
1

Check nuts on the equalizer arm bearings for tight-

ness. The serviceable life of the rubber/steel bush
bearings is dependent on the tightness of the inner
steel bush.

Tightening torques:
up to an axle load of 12 tonnes (from 08/2013)
M 42 x 3 (SW 65) M = 1300 Nm

up to an axle load of 12 tonnes (up to 07/2013)

M 42 x 3 (SW 65) M = 1100 Nm

Series HD / HDE
M 48 x 3 (SW 65) M = 1200 - 1300 Nm

2 Axle guide linkages

– twice annually, initially after 2 weeks –

Check lock nuts of the axle guide linkages/connec-

ting rods for tightness using a torque wrench.

Tightening torques:

ECO Cargo VB / VB HD
M 24 x 2 (SW 36) M = 650 Nm
M 30 (SW 46) M = 725 Nm
M 36 (SW 65) M = 1425 Nm

2 2

3 Connecting rods (only at series VB up to manu-

facturing year 08.2013 and ECO Cargo VB HD)
– twice annually –

Check connecting rod clamping screws for tight-

ness.

Tightening torques:
M 12 (SW 19) M = 66 Nm
M 14 (SW 22) M = 140 Nm

3
3
Page 90 BPW-W 33111501e

6 BPW Suspension, series ECO Cargo VB

6.3 Maintenance Work and Visual Inspection

4 Spring U-bolts
– initially after 2 weeks then twice annually – 4

Check spring U-bolts for tightness. If necessary

loosen lock nuts, tighten nuts alternately to the
prescribed torque, and a bit at a time, if necessary
then re-lock.

Tightening torques:
M 24 (SW 36) M = 600 - 650 Nm

- Visual inspection
– twice annually –

Check all component parts and welding seams for

wear and damage.

In order to check the bearing on the equalizer and

axle guide linkage, move the vehicle back and forth
slightly with the brake applied; or move the bearing
points with the aid of a lever. No play should be
present in the bearing when doing so.
BPW-W 33111501e Page 91

5 Slide elements
– twice annually –

Check slide elements and lateral wear plates in the

shackle and equalizer arm for wear and the faste-
ning screws for tightness.

Tightening torques:

M 14 (SW 22) M = 140 Nm

M 20 (SW 30) M = 320 Nm

If necessary, check rubber rollers under the spring

ends for wear. 5 5

5 5

ECO Cargo VB / VB HD
5 5
Page 92 BPW-W 33111501e

7 BPW Suspension, series ECO Cargo W / BW / GW

7.1 Overview, Lubrication and Maintenance Work, Visual Inspection

Overview

(twice annually) 1)
Every 26 weeks
Every 6 weeks
after 2 weeks
Initially
For detailed description, see pages 94 - 95
BPW trailer axles / steering axles, see pages 6 - 62
1) 1)
1 Grease axle support bearing series W, BW using BPW special longlife grease
ECO-LiPlus.

2 Grease spring housing series W using BPW special longlife grease ECO-LiPlus.

- Visual inspection, check all component parts and welding seams for wear and damage.

1 Check spring U-bolt of support axle for tightness.

M 30 x 2 (SW 46) M = 980 Nm
M 36 (SW 55) M = 1555 Nm

2 Check fastening screws on the bearing covers for tightness.

M 20 (SW 30) M = 320 Nm
M 24 (SW 36) M = 570 Nm

3 Check spring U-bolts on the spring housing for tightness.

M 20 (SW 30) M = 450 Nm
M 24 (SW 36) M = 700 Nm
1) Under extreme conditions, with more frequency.

Note:
Components that have damage due to improper mounting are to be exchanged after a review by a
BPW Service Centre.
BPW-W 33111501e Page 93

2 2

3 1 1 3

Series ECO Cargo W

3 1 2 1 2 1 3

Series ECO Cargo BW / GW ECO Cargo W / BW / GW

Page 94 BPW-W 33111501e

7 BPW Suspension, series ECO Cargo W / BW / GW

7.2 Lubrication

1 Support axle (series W, BW)

– initially after 2 weeks then every 6 weeks –
– under extreme conditions, lubricate with more
1
frequency –

Lift trailer to take pressure off the trunnion bearings.

Grease lubrication nipple front and rear on the
bearing brackets of the support axle using BPW
special longlife grease ECO-LiPlus until fresh grease
emerges (not applicable to axle assembly series
GW = rubber bush).

At extremely low temperatures (-30° C up to 50° C)

a grease with correspondingly lower consistency
class should be used - such as BPW ECO-Li Polar.
Series ECO Cargo W

Series ECO Cargo BW

2 Spring housing (series W)

– initially after 2 weeks then every 6 weeks – 2

Grease lubrication nipples on the spring housing

using BPW special longlife grease ECO-LiPlus.

Series ECO Cargo W

BPW-W 33111501e Page 95

Maintenance Work and Visual Inspection 7.3

- Visual inspection
1
– twice annually –

Check all components and welding seams for wear

and damage.

1 Spring U-bolts on the trunnion axle

– twice annually, initially after 2 weeks –

Check spring U-bolts for tightness.

If necessary loosen lock nuts, tighten nuts alter-
nately to the prescribed torque, a bit at a time, then
relock.

Tightening torques:
M 30 x 2 (SW 46) M = 980 Nm
M 36 (SW 55) M = 1555 Nm

2 Fastening screws on the cover plates

– twice annually –

Check the fastening screws on the cover plates of

the support axle for tightness.

Tightening torques: 2
M 20 (SW 30) M = 320 Nm 2
M 24 (SW 36) M = 570 Nm
1

3 Spring U-bolts on the spring housings ECO Cargo W / BW / GW

– twice annually, initially after 2 weeks –

Check spring U-bolts on the spring housings for

tightness. If necessary loosen lock nuts, tighten
nuts alternately to the prescribed torque, a bit at a
time, if necessary then relock.
Tightening torques:
M 20 (SW 30) M = 450 Nm
M 24 (SW 36) M = 700 Nm

3
 BPW-W 33111501e

Your partner on the path

to economic viability

BPW Bergische Achsen Kommanditgesellschaft

Postbox 12 80 · 51656 Wiehl, Germany · Phone +49 (0) 2262 78-0
info@bpw.de · www.bpw.de