Volvo Trucks.

Driving Progress

FACT SHEET
Fifth wheel with installation

The fifth wheel coupling provides the link between a semi-trailer and
the towing truck.
The fifth wheel coupling is normally fixed to the tractor chassis
by means of a mounting plate. Various mounting plates, fifth wheel
mounting heights and fifth wheel leg heights are available to make
an accurate match between the height of the fifth wheel and existing
trailer systems possible.

The following areas are described below:

– Type
– Mounting
– Leg–Height
– King Pin Diameter
– Maintenance Level
– Lubrication
– Trailer Connection Indicator
– Coupling Height

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FACT SHEET
Fifth wheel with installation

TYPE (sales variants in bold)

5WT-JO8
Jost JSK 37C cast iron fifth wheel. Rubber bearing and suitable
for poor quality roads. Available with a number of different heights
above the frame depending on both fifth wheel mounting and
fifth wheel leg height.

5WT-JO9
Jost JSK 42 weight optimized cast iron fifth wheel. Plastic bear-
ing protects the chassis due to its longitudinal elasticity (lateral
movement). Available with a number of different heights above
the frame depending on both fifth wheel mounting and fifth
wheel leg height.

5WT-JO10
Jost JSK 36 pressed steel fifth wheel. Pivot bearing protects
the chassis due to its longitudinal elasticity (lateral movement).
Available with a number of different heights above the frame
depending on both fifth wheel mounting and fifth wheel leg
height.

5WT-JO11
Jost JSK 38G cast iron heavy duty fifth wheel. Cardan bearing to
allow roll between tractor and semi-trailer under off-road condi-
tions. The lateral suspension can be disabled for on-road use.
For 90 mm (3.5") king pin diameter.

5WT-JO16
Jost JSK 34H weight optimized cast iron fifth wheel. Suitable
for long haul operations with 5WM-LPRO mounting providing
a low weight solution. New hybrid bearing, a combination of
robust shock absorbing rubber bearing (as in JSK 37C) and a
plastic bearing.

5WT-JOHD
Jost JSK 38C cast iron heavy duty fifth wheel. Rubber bearing
and suitable for poor quality roads. Available in two versions, for
50 mm (2") king pin or for 90 mm (3.5") heavy duty king pin.

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FACT SHEET
Fifth wheel with installation

5WT-FO14
Fontaine 150SP2 pressed steel fifth wheel. Mounted on outward
facing L-profiles. Weight optimized. Available with a number of
different heights above the frame depending on both fifth wheel
mounting and fifth wheel leg height.

5WT-FO15
Fontaine 3000 series cast iron air actuated fifth wheel. Standard
duty, 100% on highway. Extra large king pin plate contact area
(almost 360° contact area around king pin when closed) reduces
wear, improves handling and provides added roll-over resistance.

5WT-SH
SAF-Holland/+GF+ SK-S 36.20 cast iron fifth wheel. Permanent
maintenance free bearing with rubber damper. Suitable for the
5WM-LPRO mounting providing a low weight solution. Available
with a number of different heights above the frame depending
on both fifth wheel mounting and fifth wheel leg height.

5WT-SH2
SAF-Holland/+GF+ SK-HD 38.36 cast iron heavy duty fifth
wheel. Permanent maintenance free bearing with rubber
damper. Available in two versions, for 50 mm (2") king pin or for
90 mm (3.5") heavy duty king pin.

5WT-SH5
SAF-Holland/FWAL-E forged aluminum fifth wheel. Top plate
with pads for low maintenance and NoLube locking mecha-
nism for minimized maintanance. Available with three different
installations. This is the low weight option when 5WM-LPRO
can't be used.

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Fifth wheel with installation

Type Specification

Sales variant 5WT-JO8 5WT-JO95WT-JO105WT-JO115WT-JO165WT-JOHD5WT-FO145WT-FO155WT-SH5WT-SH25WT-SH5

SAF- SAF- SAF-

Manufacturer Jost Jost Jost Jost Jost Jost Fontaine Fontaine
Holland Holland Holland
SK-S SK-HD
Type designation JSK 37C JSK 42 JSK 36 JSK 38G JSK 34H JSK 38C 150SP2 3000 FWAL-E
36.20 38.36

D-Value kN 152 152 1521/1352 260 120 260/170 152 150 152 260/162 150

U-Value ton 20 20 201/182 36 16 36/28 20 20 20 36/23 20

Weight kg (approx.) 150 125 125 275 110 200 120 120 150 185 94

King pin diameter mm 50 50 50 90 50 90/50 50 50 50 90/50 50

Trailer connection
Option Option – – – – – – Option – –
indicator

Low Option Option – – Standard – – – Option – –

Maintanence
Basic Option Option Standard Standard – Standard Standard Standard Option Standard –
level

Free – – – – – – – – – – Standard

Locking
Option Option – – Standard – – – Option – –
mechanism
Lubrication Locking
mechanism Option Option – – – – – – – – –
and top plate

1
For fifth wheel mountings 5WM-ISOL, 5WM-ISOM, 5WM-ASL and 5WM-ASM.
2
For fifth wheel mounting 5WM-LPRO.

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FACT SHEET
Fifth wheel with installation

MOUNTING (sales variants in bold)

5WM-ISOL
Mounting plate bolted to two low L-profiles with outward facing
flanges. Suitable for all kinds of fifth wheels. Sliding members
are not included in the variant.

5WM-ISOM
Saddle with two crossmembers and two tie plates are bolted
to two medium high L-profiles with outward facing flanges.
Suitable for all kinds of operations. Sliding members are not
included in the variant.

5WM-ISOH
Saddle with two crossmembers and two tie plates are bolted to
two on top of frame mounted high Z-profiles with outward facing
upper flanges. Optimized for T-ride rear axle installations. Sliding
members are not included in the variant.

5WM-ISHD
High grade steel plate saddle with two crossmembers are bolted
to two on top of frame mounted high Z-profiles with outward
facing upper flanges. Available for both leaf and air suspended
rear axle installations. Possibility to get a complete heavy haul-
age truck from factory.

5WM-LPRO
Mounted directly to the chassis frame with two inverted L-profiles
(facing inward). 5WM-LPRO has no saddle and no mounting
plate which allow for low coupling heights. Light wheel alternative
making it perfect for weight sensitive operations.

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Fifth wheel with installation

5WM-DH
Mounting plate bolted to two low L-profiles with outward facing
flanges. 5WM-DH has compressed air operated dual heights
which improves flexibility. Height change must be done without
trailer. When changing from low to high height, the fifth wheel
moves 30 to 40 mm towards the cab. Handles both standard
and mega trailers. Integrated pneumatic control box. Automatic
lubrication of hinges.

5WM-MASL
Mounting plate bolted to two low L-profiles with outward facing
flanges and adjustable manual slide. Two crossmembers and
L-profiles bolted to frame. 5WM-MASL has no saddle.

5WM-MASM
Mounting plate bolted to two medium high L-profiles with outward
facing flanges and adjustable manual slide. Two crossmembers
and L-profiles bolted to frame. 5WM-MASM has no saddle.
Usable for heavy duty ramps with 220 mm fifth wheel leg height.

5WM-ASL
Mounting plate bolted to two low L-profiles with outward facing
flanges and adjustable manual slide. Two crossmembers and
L-profiles bolted to frame. 5WM-ASL has no saddle. The fifth
wheel mounting has self locking mechanism and pneumatically
operated release mechanism (switch in dashboard). Optimized
for Volvo.

5WM-ASM
Mounting plate bolted to two medium high L-profiles with outward
facing flanges and adjustable manual slide. Two crossmembers
and L-profiles bolted to frame. 5WM-ASM has no saddle. The
fifth wheel mounting has self locking mechanism and pneu-
matically operated release mechanism (switch in dashboard).
Optimized for Volvo.

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FACT SHEET
Fifth wheel with installation

Mounting Specification

Sales 5WM- 5WM- 5WM- 5WM- 5WM- 5WM- 5WM- 5WM- 5WM- 5WM-
variant ISOL ISOM ISOH ISHD LPRO DH MASL MASM ASL ASM

Fifth Jost Jost Jost Jost

Jost
wheel Fontaine Fontaine Fontaine Fontaine Jost Jost Jost Jost
Fontaine Jost
manu- SAF- SAF-Hol- SAF-Hol- SAF-Hol- Fontaine Fontaine Fontaine Fontaine
facturer SAF-Holland
Holland land land land

Adjustable Adjustable Adjustable Adjustable

Type Fixed Fixed Fixed Fixed Fixed Fixed manual manual manual manual
slide slide slide slide

N/A
Max See fifth
imposed
20 20 20 36 wheel 15 20 20 20 20
load (U)
(tonnes) specifica-
tion table
N/A
Max See fifth
D-value 152 152 152 269 wheel 110 150 150 152 152
(kN) specifica-
tion table
Height
above
chassis
4 + 12 50 + 10 80 + 10 80 + 16 0* 4 4 50 4 50
frame
+ saddle
(mm)

Travelling Jost Jost Jost Jost

length/ N/A N/A N/A N/A N/A N/A 610/50.8 610/50.8 610/50.8 610/50.8
incre- (Not ap- (Not ap- (Not ap- (Not ap- (Not ap- (Not ap-
ment plicable) plicable) plicable) plicable) plicable) plicable) Fontaine Fontaine Fontaine Fontaine
(mm) 487/37.5 487/37.5 487/37.5 487/37.5

* For 5WM-LPRO the 8 mm L-profile is included in the total fifth wheel height.

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Fifth wheel with installation

LEG-HEIGHT (sales variants in bold)

Fifth wheel height in mm from foot, upper edge of mounting, to
the top of the wheel in horizontal position (B). An exception is
the fifth wheel mounting 5WM-LPRO, that is measured from the
upper edge of the frame to the top of the wheel in horizontal
position (A).

5WH 140 Fifth wheel leg-height 140 mm

5WH 150 Fifth wheel leg-height 150 mm
5WH 160 Fifth wheel leg-height 160 mm
5WH 175 Fifth wheel leg-height 175 mm Simplified sketch of the measuring.
A – measurement for 5WM-LPRO.
5WH 185 Fifth wheel leg-height 185 mm
B – measurement for the other fifth wheel mountings.
5WH 190 Fifth wheel leg-height 190 mm
5WH 195 Fifth wheel leg-height 195 mm
5WH 200 Fifth wheel leg-height 200 mm
5WH 205 Fifth wheel leg-height 205 mm
5WH 210 Fifth wheel leg-height 210 mm
5WH 220 Fifth wheel leg-height 220 mm
5WH 230 Fifth wheel leg-height 230 mm
5WH 260 Fifth wheel leg-height 260 mm
5WH 290 Fifth wheel leg-height 290 mm
5WH17D37 Fifth wheel dual leg-heights, 167 and 367 mm

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FACT SHEET
Fifth wheel with installation

Leg-Height Overview (sales variants)

5WT-JO8 5WT-JO9 5WT-JO10 5WT-JO115WT-JO16 5WT-JOHD 5WT-FO14 5WT-FO15 5WT-SH 5WT-SH2 5WT-SH5

5WH150 5WH150 5WH150

5WM-ISOL 5WH185 5WH185 5WH150
5WH185 5WH185 5WH185

5WH150 5WH150 5WH150

5WM-ISOM 5WH185 5WH210 5WH150
5WH185 5WH185 5WH185

5WH150 5WH150 5WH150

5WM-ISOH 5WH290 5WH190 5WH150
5WH185 5WH185 5WH190

5WH150
5WM-ISHD 5WH290 5WH190
5WH190

5WH160 5WH160 5WH140

5WH160 5WH160
5WM-LPRO 5WH200 5WH200
5WH200 5WH200
5WH230 5WH230 5WH230

5WM-DH 5WH17D37

5WH175 5WH175
5WM-MASL 5WH205 5WH195
5WH260 5WH220

5WH175 5WH175
5WM-MASM 5WH205 5WH195
5WH260 5WH220

5WH175 5WH175
5WM-ASL 5WH205 5WH195
5WH260 5WH220

5WH175 5WH175
5WM-ASM 5WH205 5WH195
5WH260 5WH220

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Fifth wheel with installation

KING PIN DIAMETER

(sales variants in bold)
TRAILER CONNECTION INDICATOR
KPSIZE50 King pin diameter 50 mm (2 inches). (sales variant in bold)
KPSIZE90 King pin diameter 90 mm (3.5 inches).
TCIND Fifth wheel equipped with sensors for height,
king pin and coupling lock. Trailer connection
MAINTENANCE LEVEL indication is shown in the driver information
(sales variants in bold) display.
5WLM-B Basic fifth wheel maintenance level (for locking
mechanism and top plate). LUBRICATION
5WLM-L Low fifth wheel maintenance level (for locking (sales variants in bold)
mechanism). Plastic slide plates and wearing
5WL-S1 Locking mechanism and top plate lubrication.
ring.
5WL-S2 Locking mechanism lubrication.
5WLM-F Maintenance free fifth wheel level for locking
mechanism and low maintenance level for top
plate.

5WT-JO8, 5WLM-L

5WT-JO, 5WL-S1

5WT-SH, 5WL-S2

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Fifth wheel with installation

COUPLING HEIGHT (examples for air suspended vehicles)

Rear axle Frame Fifth wheel leg- Min. coupling height Nominal drive height
Axle arrangement Chassis height Tyre
installation height height + flange, mm (approx), mm (A) (approx), mm (A)
RAD-GR 266 140+0 295-55 867 912
X-Low
266 140+0 295-60 887 932
Low RAD-GR 266 140+0 315-60 955 1015
4x2 RAD-GR 266 140+0 315-70 1014 1075
Med
300 140+0 315-70 1031 1092
RAD-GR 266 140+0 315-80 1056 1147
High
300 140+0 315-80 1090 1164
Low RADT-GR 266 160+0 315-60 975 1035
RADT-GR 266 160+0 315-70 1034 1095
Med
300 160+0 315-70 1051 1112
High RADT-GR 300 150+60 315-80 1160 1234
6x2
RAPD-GR 266 160+0 315-70 1034 1095
Med
300 160+0 315-70 1051 1112
RAPD-GR 266 160+0 315-80 1076 1167
High
300 160+0 315-80 1110 1184
6x4 High RADD-GR 300 150+60 315-80 1173 1234

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