FORD 4R44E, 4R55E, 5R44E, 5R55E

ZIP KIT ®
PART NUMBER 4R44E-5R55E-ZIP QUICK GUIDE
Parts are labeled here in order of installation. See other side of sheet for details on kit contents.

installation Diagram
Separator Plate Valve Body
NOTE: Kit now
includes OE ratio CAUTION:
6C boost assembly to re-
1 3 See note
store OE pressure curve. on page 2.
6A Line-to-Converter Release
Drill to .062" diameter.
Balance Pressure Regulator NOTE: Increased
Drill to .055" diameter. strength spring is 1 2
optional, to provide
moderately increased
pressure.
5
5

5
8 Plastic
Checkball
Shown in
4A 4 places.

4E 4B
CAUTION:
4C

See note
on page 2.

8
8

4D 8

6B
OD Servo Apply
6D TCC Modification
Drill to .110" diameter.
Drill to .072" diameter. 7
6C TCC Modification TCC Modification
Drill to .062" diameter. Insert Remove smallest inboard
aluminum plug & peen in place. spring through casting
NOTE: See pages 1–2 in separate Installation port on reverse side of
and Testing Booklet for installation tips and valve body.
additional optional modifications

In addition to general rebuilding tips and technical information, the technical booklet included in this kit contains vacuum
testing and additional repair options for higher mileage units or for repairing specific complaints which are beyond the
scope of this kit.

©2019 Sonnax Transmission Company, Inc. • A Marmon / Berkshire Hathaway Company 4R44E-5R55E-ZIP-Guide_C 12-09-19

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 FORD 4R44E, 4R55E, 5R44E, 5R55E ZIP KIT® Quick Guide

Kit Contents & Installation Steps

Step 1 Replace OE Boost Assembly Step 5 Replace OE Checkballs, EPC
NOTE: Kit now includes OE ratio boost assembly to restore OE Limit Valve & Lube Orifice Plug
pressure curve. Sonnax increased strength spring is optional,
to provide moderately increased pressure when used to replace OE Packaging Pocket 9
large diameter spring.
• Plastic Checkballs (4) • EPC Limit Valve, Reuse OE Spring
NOTE: For firmer shifts and significantly increased line pressure, use • Lube Orifice Plug • "L" Pins (2), Extra, for lost/missing OE pins
Sonnax increased ratio boost valve kit 37947-03K, sold separately.

Packaging Pocket 1

• Valve • Sleeve • Spring Step 6 Drill Separator Plate in

Locations & Diameters Given
Step 2 Replace OE FWD Modulator Valve Packaging Pocket 10
NOTE: Insert PTFE seal in valve groove and size in bore first. 6A. Balance Line Orifice Modification Drill Bit
Packaging Pocket 2 Drill Bit, .055" dia.
• Forward Modulator Valve • PTFE Seal 6B. OD Servo Apply Orifice Modification Drill Bit
Drill Bit, .072" dia.

Step 3 Replace OE Solid Plug 6C. L

 ine-to-Converter & TCC Modification
Drill Bit & Plug
CAUTION: If OE end plug has relief orifices and tabs, DO NOT
INSTALL this Sonnax O-ringed end plug and spring. Reuse OE NOTE: Drill two orifices and install and peen plug into plate as

end plug. Reference page 1, step 3 of Installation Booklet for details. shown on page 1.
CAUTION: Included spring is OPTIONAL and provides firmer • Drill Bit, .062" dia. • Aluminum Plug .062" dia.
forward engagement. Remove if drive test proves forward
engagement is too harsh.
6D. TCC Modification Drill Bit
Packaging Pocket 3 Drill Bit, .110" dia.
• Forward Modulator End Plug • O-Ring, Large • Spring

Step 7 TCC Modification

Step 4 Replace OE End Plugs
NOTE: Remove smallest inboard cooler bypass spring
4A. Reverse Modulator O-Ringed End Plug through idicated casting port.
Packaging Pocket 4
• End Plug • O-Rings, Medium (3) 1 Extra
Step 8 Replace OE Solenoid O-Rings
4B. 2-3/3-4 Shift Valve O-Ringed End Plug
Packaging Pocket 11
Packaging Pocket 5
• End Plug • O-Rings, Small (2) • O-Rings, Small (4) • O-Rings, Large (4)

4C. 1-2/2-3 Shift Valve O-Ringed End Plug

NOTE: Reuse OE plunger valve inside plug. Extra O-Rings for End Plugs in Step 4
Packaging Pocket 6
Packaging Pocket 12
• End Plug • O-Rings, Medium (3) 1 Extra
• O-Rings, Small (2)
4D. Converter Reg. Valve O-Ringed End Plug & Spring • O-Rings, Large (2)
Packaging Pocket 7
• End Plug • O-Ring, Large • Spring, Install only if OE is damaged

4E. O-Ringed End Plugs

Packaging Pocket 8
• End Plug, Large • O-Rings, Large (2)
• End Plugs, Small (2) • O-Rings, Small (4)

©2019 Sonnax Transmission Company, Inc. • A Marmon / Berkshire Hathaway Company 4R44E-5R55E-ZIP-Guide_C 12-09-19

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 FORD 4R44E, 4R55E, 5R44E, 5R55E
ZIP KIT ®
PART NUMBER 4R44E-5R55E-ZIP INSTALLATION & TESTING BOOKLET

Torque Specifications Valve Body Rebuild Tips & Techniques

Band Adjuster Lock Nut Transmission Oil Pan Bolt Bore-by-bore tips for removal, installation, options and checks of valve body
35 to 45 ft-lb 115 to 133 in-lb components. The detailed steps below correlate to the quick guide steps.
Converter Housing-to-Case Converter-to-Flywheel
27 to 39 ft-lb 22 to 30 ft-lb 1. Replace OE Boost Assembly
Extension Housing-to-Case Oil Pump-to-Cnvtr Housing Kit now includes an OE ratio boost assembly to restore OE pressure curve. Sonnax
27 to 39 ft-lb 16 to 21 ft-lb increased strength spring is optional, and will provide moderately increased pressure
Manual Lever Inner Nut Manual Lever Outer Nut (approximately 5 psi in Drive and 6 psi in Reverse) when used to replace the OE large
30 to 40 ft-lb 30 to 40 ft-lb diameter spring. For firmer shifts and significantly increased line pressure, use Sonnax
Oil Cooler Line-to- Oil Cooler Line-to- increased ratio boost valve kit 37947-03K, sold separately. This increased ratio kit
Connector Nut Connector 5/16" Tube Nut is NOT recommended for smaller 4-cylinder applications, or if testing determines
18 to 23 ft-lb 26 to 32 ft-lb that the Sonnax EPC and engagement control kit 37947-11K (sold separately) is
Transmission-to-Engine Low-Reverse Servo necessary and installed.
28 to 38 ft-lb (Except 3.0L) Cover Bolt
33 to 44 ft-lb (3.0L) 106 to 124 in-lb 2. Replace OE Forward Modulator Valve
Center Support-to-Case Bolt Separator Plate Bolt By positioning the manual valve furthest into the bore, air pressure can be used to blow
80 to 115 in-lb 53 to 71 in-lb the modulator valve out. If there is any visible wear or ridge in the bore, buff this area
TR Sensor Valve Body-to-Case Bolt with Scotch-Brite™ placed on a twisted wire and inserted into drill. Install the PTFE
71 to 98 in-lb 71 to 98 in-lb seal onto the Sonnax valve. Invert the valve and push into the bore just far enough to
size the PTFE seal. After sizing the seal, install the OE forward modulator spring into
Recommended Fluid & Capacities the end of the Sonnax valve and install into the bore (illustrated in Quick Guide).
Mercon V (XT-5-QM) ATF
4R44E 2WD, 2.3L 4R44E 2WD, 3.0L
3. Replace OE Solid Plug
9.9 Qts (9.4L) 10.0 Qts (9.5L)
If OE end plug has relief orifices and tabs (Figure 1), DO NOT INSTALL the
4R44E 4WD
included Sonnax O-ringed end plug and spring. Reuse the OE end plug. If the
10.4 Qts (9.8L)
OE end plug is solid, discard and replace with the Sonnax O-ringed end plug and
5R55E 2WD 5R55E 4WD optional spring if desired.
10.0 Qts (9.5L) 10.3 Qts (9.8L)
Optional Step: Seal the “L” pin circuits at the forward and reverse modulator valve
bores (inboard at bores in steps 3 and 4). These locate and hold plugs which separate
and seal oil circuits. As the valves toggle, the plugs become loose and allow fluid to
pass around them. It is suggested to vacuum test the area for severe wear first (reference
Figure 1 page 7) to determine if refurbishing the bore is a better option. The following sealant
process requires cure time, so time must be allowed. Using Permatex® Surface Prep
Activator #24163 or a similar product, clean the middle plug and “L” pin area from
both sides and through the open bore. Air dry, then drip a small amount of Loctite®
609 or 3M #04732 sealant into the “L” pin opening. This must have a cure time to
Solid OE hold properly. Epoxy is not suggested, as it is permanent. Loctite can be heated to
End Plug
allow removal. To remove plugs once sealed, heat the area until the sealant melts, then
air dry. Flat stone the valve body surface and clean well to remove surface imprints.
OE End Plug
with 4. Replace OE End Plugs
Relief Orifices
and Tabs a. Most plugs require two O-rings and have a tapped hole to allow for easy
removal in the future. To install, lube the plug, slip on the O-rings and roll
the plug on a clean surface to seat the O-rings. Verify that the valves and
springs are in their original positions and install the end plugs with the tapped
hole facing out. Extra O-rings are supplied in case an O-ring is torn during
Forward Modulator Valve OE End Plugs installation.

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 FORD 4R44E, 4R55E, 5R44E, 5R55E ZIP KIT® Installation & Testing Booklet

4. Replace OE End Plugs (continued) Figure 2

b. The OE “U”-shaped retainer is used to hold the plug into the casting, and
should be inserted into the plug groove between the two O-rings. The outer
plug groove will protrude from the bore and is used to help retain the OE
solenoid bracket.
c. Remove the plug between the EPC solenoid and the 1-2/2-3 shift valve. The
plug may not come out easily after removing the “U”-shaped retainer. A rod
(.125" dia.) can be inserted into the opposite bore (113, page 7) to drive out
the plug. After the plug is removed, push the shift valve to the bottom of
the bore and retain it with a screwdriver. Install the small OE plunger valve
into the Sonnax O-ringed plug before installing into the bore. The large OE
“U”-shaped retainer should be installed with the longer leg closest to the
manual valve. For bore 109 valve removal, drill .110" dia. hole, entering
at bolt and exiting into spring pocket of bore 109.
d. Pull out the “L” pin near the solenoid. The OE plug can be difficult to remove. This allows rod to drive out the valve.
With a strong needle-nose pliers, turn the plug and hit it with the tip of your
pliers. Continue this until the spring drives out the plug. If the OE plug
will not come out, you must also remove the inner “L” pin retainer. You will
then have to drill an access hole to drive out the valves (Figure 2). A new
spring is supplied for the inner coast clutch valve in case the OE is damaged
during this process. Use the needle nose pliers to install the Sonnax end plug
(O-ring only) by holding the small nub. Twist while inserting the plug until
the O-ring is inboard of the “L” pin retainer port.
e. These three plugs seal shift solenoid oil. The two smaller end plugs use four
small O-rings. The larger end plug is .630" in diameter, and uses two large
O-rings.

5. R
 eplace OE Checkballs, EPC Limit Valve 7. TCC Modification
& Lube Orifice Plug Remove the smallest spring from the cooler bypass
Replace the four OE checkballs with the new Torlon® balls included, ensuring prop- valve bore. This spring can be pulled out from the
er location. Replace the OE lube orifice. Replace the OE EPC relief valve with the lower side of the casting, through the slot next to the
Sonnax domed relief, reusing the OE spring. The TCC relief and the EPC relief filter inlet (Figure 3).
springs are interchangeable. Two replacement “L” pins are included in case originals
are lost or damaged. 8. Replace OE Solenoid O-Rings
Replace small and large O-rings from the four
6. Drill Separator Plates indicated solenoids (see Quick Guide). Lube the
a. Drill the pressure regulator balance orifice to .055" dia. with included drill. To O-ringed solenoid snout prior to bore installation.
prevent flashing, start the drill on one side and then finish from the opposite. It’s
always best to taper the orifice holes when done with a larger drill.
b. Drill the overdrive servo apply orifice to .072" dia. with included drill. This Figure 3
will supply firmer 4th in 4R units and firmer 5th and 2nd in 5R units. Later
5R55E units are already this size.
c. Drill line pressure circuit to converter feed orifice in the plate to .062" dia.
with included drill. Late-model 5R55E units are already this size. Drill the
indicated converter clutch orifice to .062" dia., then insert the included .062"
aluminum plug and peen in place to close off the hole.
d. Drill the TCC exhaust hole to .110" dia. with included drill.

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 FORD 4R44E, 4R55E, 5R44E, 5R55E ZIP KIT® Installation & Testing Booklet

Separator Plate & Relief Valve Information

4R44E Plate

5R55E Plate: has

bathtub checkball,
ahead of bolt hole.
If there is a hole
here, use includ-
ed EPC relief tee and
OE spring. If there is
no hole here, you
must use blow-off end This plate and part number
plug at forward does not have an EPC relief
modulator valve hole (Figure 3) and must be
(Figure 5). End plug used with OE part # 3L5Z-
installs here. Figure 4 7M203-JA end plug relief. Figure 5 Figure 6

Rebuilding Cautions
• Do not combine aftermarket parts or procedures • Do not use a stronger pressure regulator valve
with this kit. spring or shim than the ones supplied.
• Do not drill line-to-lube through the casting at the • Do not remove springs or block reverse engagement
pressure regulator valve. control valve.

Troubleshooting Tips No 2nd, 1-2 Slide or Soft 2nd

These tips are not about common problems such as blown gaskets or dirty valve
Gear Starts
bodies. These only include valve body problems not visible during a rebuild. • Air test the rectangular circuit five openings in from
EPC solenoid. No cross leakage should be visible!
No/Slow Reverse • Look for bore wear at the forward modulation
valve (repaired by 37947-11K, not included in this
• The SSA solenoid must be turned on, allowing flow through the solenoid, or
Zip Kit), This valve controls the servo apply rate.
direct clutch will not apply until EPC rises to 20 psi. The direct clutch psi
• If the plug that lives in the middle of OE assembly
will then slowly rise following EPC until clutch holds.
(repaired by 37947-11K, not included in this Zip Kit),
• Always install new servo pistons. Both servos are charged on the release side
is loose and bore leaks, a poor 1-2 and/or 2-3 results.
in reverse.
• Inspect the center support sleeve, sealing rings and direct drum sleeve for cracks. No 2nd or 4th, Erratic Direct
• Ensure the vehicle has line rise, as reverse will not engage until line is 120 psi. Clutch, No Upshift
Delayed Reverse & Forward The solenoid regulator valve is likely out of position.
The separator plate must be aligned with pins. If not, the bolt threads will separate With SSB solenoid removed, the end of the casting to
the case from the plate, causing a line pressure leak. edge of the long aluminum plug will measure 1.720"
when “L” pin is installed properly.
Servo Covers Blown Out of Case
Inspect for causes of high line psi such as pressure regulator bore or boost sleeve
No Coast Clutch Pressure
wear, or line booster valve stuck inboard. • Inspect the bore plug for wear at the TCC regulator
valve. Sonnax TCC regulator sleeve kit 37947–09K
Servo Rubber Separated/Blown Off (not included in this Zip Kit) eliminates the leak
and bore plug here.
This often occurs from pre-assembly damages, so inspect carefully before install-
• The bore for the coast clutch shift valve wears out.
ing. The rubber lip separation occurs from heat and high pressure. Both servos are
Insert the valve: no side-to-side movement should
pushed toward the cover in reverse, so check for cause of high line pressure.
be visible.

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 FORD 4R44E, 4R55E, 5R44E, 5R55E ZIP KIT® Installation & Testing Booklet

Troubleshooting Tips (continued) Shift Solenoids

It is very rare to have a shift solenoid problem on these
No Overdrive Servo Apply psi units. It’s more common to have a loss of solenoid oil
• The coast clutch shift valve may be out of position, the bore worn severely or psi due to loose end plugs.
the dumbbell-shaped valve (opposite bore from the TCC modulator) is not
being retained correctly. EPC Circuit Testing
• This “L” pin falls out of position easily. The most effective method to isolate the EPC circuit is
• Timing valve may be stuck toward the end plug or the spring is not on to perform an wet air test with fluid while the body is
center, which causes it to coil bind. still bolted to the case. This can be done in the vehicle
• Kickdown valve may be stuck or spring missing. or at the bench. A quick test adapter can be made from
an old 4R/5R EPC solenoid. The coil housing and
No OD Servo Release valve will be removed and a plug or epoxy used to seal
(No Overdriven 2nd in 5R & No 4th in 4R) the inboard circuit (Figure 7).
Mismatched separator plate at 5R/4R identification (Figure 6). Supply 40-60 psi of air into the adapter. No leaks
should be visible at the locations shown in Figure 8.
OD Band Failure, No Overdrive Release psi Any leakage is reduction of EPC pressure and line rise
The 3-4 shift valve may not be positioned due to a loose SSC solenoid. Bracket must while in operation. Remember, though, as operating
hold it in flush. temperature increases, valve clearance and the flow rate
(viscosity) of ATF increase. You can duplicate hot fluid
Broken Bands, No EPC Blow-Off, EPC psi Too High at the bench by filling the case and valve body with
solvent, then bolt up and test with the adapter.
Relief Tee near the pressure regulator is not opening or mismatched plate without a
hole here and no relief used at forward modulator end plug. The EPC spring bore
is often tapered, which alters spring operation. The Sonnax EPC and engagement
control kit 37947-11K (not included in this Zip Kit) addresses this problem.

Low EPC, Soft Shifts, Slip in 3rd

Multiple EPC leakage points. Use the Sonnax EPC and engagement control kit
37947-11K (not included in this Zip Kit), which address this entire circuit. Good
maximum EPC is 125-130 psi in OD and maximum of 144 in reverse. EPC should
not drop more that 15 psi during TCC apply.
Old 4R/5R
Low EPC Pressure & No Lockup Control EPC Solenoid
If TCC modulator valve sticks, EPC will only obtain about 65 psi.
Figure 7
Flare on 2-3 Shift, 4R (3-4 on 5 Speed)
The servo pin bore is worn on the intermediate servo, or the spring on the piston is
40-60 psi supplied to modified EPC solenoid/tool.
too strong.

No 3rd or 4th
The 2-3 shift valve spring is missing or installed wrong. Also, the 1-2 shift valve
should stroke during wet air test (WAT) at the rectangular circuit five openings in
from EPC solenoid.

TCC Applied Prematurely, Harsh Shifts

If the solenoid is restricted or grounded, the TCC valve can stroke and apply the
converter clutch.

Poor Converter Charge, Delayed Engagements

The balance spool or innermost bore for the pressure regulator is worn out. “Tired” valve bodies leak at any
or all of these locations. Figure 8

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 FORD 4R44E, 4R55E, 5R44E, 5R55E ZIP KIT® Installation & Testing Booklet

Apply Component Chart

Front Reverse

Forward Clutch
Intermediated

Reverse Band
GEAR One-Way One-Way

Direct Clutch
Coast Clutch

Coast Clutch
Front Band
Clutch Clutch

‘95-‘96

‘97-‘00

Coast

Coast
Band

Drive

Drive
4R44E/ Shifter
4R55E 5R55E Position
Reverse Reverse Reverse A A* A H OR†
1st 1st Overdrive A* A H OR† H OR
2nd Overdrive A A OR OR H OR
2nd 3rd Overdrive A A* A* A H OR †
OR OR
3rd 4th Overdrive A* A* A A H OR† OR OR
4th 5th Overdrive A A A OR OR OR OR
Manual 2 Manual 2
2 A A A A H OR OR OR
Position Position
Manual 1 Manual 1
1 A A A A H OR H OR
Position Position
Planetary Component FRS FS RP FRS FRS FS FR FRS RP

Apply Component Chart Key: Figure 9

A = Applied * = Applied, TCS on FS = Forward Sun Gear
H = Holding †
= Ineffective, TCS on RP = Reverse Planet Assembly
OR = Overrunning FRS = Front Sun Gear FR = Forward Ring Gear

Solenoid Apply Chart

Transmission Powertrain Control Module Shift Solenoids
Range Selector (PCM) Gear Commanded
Lever Position SSA SSB SSC SSD/CCS
4R44E/4R55E 5R55E
Park/Neutral Park/Neutral Park/Neutral On Off Off Off
Reverse Reverse Reverse On Off Off Off
1 1 On Off Off Off
2 On Off On Off
Overdrive
2 3 On On Off Off
(TCS Off)
3 4 Off Off Off Off
4 5 Off Off On Off
1 1 On Off Off Off
Overdrive 2 On Off On On*
(TCS On) 2 3 On On Off On*
3 4 Off Off Off On
2 3 On On Off On
Manual 2nd
3 A
4 A
Off Off Off On
1 1 On Off Off On
Manual 1st 2 A
On Off On On
2 A* On On Off On

Apply Component Chart Key: Figure 10

A = When a manual pull-in occurs above calibrated speed, the transmission will not downshift
until the vehicle speed drops below this calibrated speed.
* = Model and calibration dependent.

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 FORD 4R44E, 4R55E, 5R44E, 5R55E ZIP KIT® Installation & Testing Booklet

Solenoid & Bolt Locations Bolt

Color Code
Bolt Lengths
No. Bolts
Required
Install bolts in sequence indicated by numbers. Colors indicate bolt lengths, see chart for details. Red 20mm 4
Green 30mm 1
Yellow 35mm 2
Blue 40mm 16
Coast Clutch Solenoid Shift Solenoid B (SSB) 22–48 ohms
(CCS/SSD) 22–48 ohms Orange 45mm 4

EPC Solenoid 3.1–5.7 ohms Purple 55mm 1

TCC Solenoid 8.9–16 ohms

13
23
16 8
4
5 17 19

12
20
28 9 21
15
1
24
26
10
18 3 11
2

27 25
22 14 6 7

Shift Solenoid C (SSC) 22–48 ohms Shift Solenoid A (SSA) 22–48 ohms

OE Spring Identification Chart

Wire Free Wire Free
Bore Valve Springs O.D. Coils Color Bore Valve Springs O.D. Coils Color
Dia. Length Dia. Length
.665"- 109 TCC Regulator, Outer .285" .040" .787" 9.5 Orange
101 Forward Control .338" .032" 6.5 White
-.775" 109 Coast Clutch. Bottom Bore .222" .023" .840" 9.5 Red
102 Pressure Regulator, Outer .745" .055" 1.065" 4 Plain/Lt. Purp. 110 TCC Modulator .238" .023" 1.230" 11.5 White/Yellow
102 Pressure Regulator, Inner .412" .032" 1.135" 9.5 Lt. Green 111 Thermal Outer, Big .575" .042" 1.045" 4.5 White
103 Forward Modulator .236" .026" .738" 14 White 111 Thermal, Middle .264" .026" 1.232" 13.5 Lt. Green
103 EPC Boost .293" .040" 1.210" 12 Orange 111 Inner Limit (smallest) .200" .018" .840" 12 Blue
105 Reverse Modulator, Outer .210" .018" 1.080" 10.5 Plain 112 3-4/4-5 Shift .280" .032" 1.162" 12 Plain
105 Reverse Modulator, Inner .210" .018" 1.080" 10.5 Plain 113 Throttle Downshift .263" .028" .700" 6.5 Orange
106 2-3/3-4 Shift .275" .030" 1.052" 13 Plain 114 Manual Low .320" .032" .985" 7.5 Yellow
107 1-2/2-3 Shift .284" .033" .730" 7 Lt. Purple 115 Kickdown .262" .028" .670" 7 Orange
108 Solenoid Regulator .218" .030" .830" 8.5 Yellow N/A Steel EPC Relief Tee .292" .040" .982" 13.5 Plain
109 TCC Regulator, Inner .187" .028" .720" 12 White N/A Plastic TCC Relief Tee .292" .040" .982" 13.5 Plain

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 FORD 4R44E, 4R55E, 5R44E, 5R55E ZIP KIT® Installation & Testing Booklet

Critical Wear Areas & Vacuum Test Locations 20

25
30
15

0
10
5

NOTE: OE valves are shown in rest position and should be tested in rest position unless otherwise indicated. Test locations are pointed VACUUM
TEST

to with an arrow. Springs are not shown for visual clarity. Low vacuum reading indicates wear and Sonnax parts are noted for replacement.
For specific vacuum test information, refer to individual part instructions included in kits and available at www.sonnax.com.

Boost Valve Assembly EPC Boost Valve,

• Delayed Reverse • Soft shifts Forward Modulator Valve
• Low line pressure • Poor modulator control & Reverse Modulator Valve
Replace with Sonnax Part No. • 2nd Gear starts • No Reverse • Poor shift quality
37947-01K OE Ratio • Flare on 1-2 or 2-3 shift on 4R, or 2-3, 3-4 on a 5R
37947-03K* Increased Ratio • Delayed Forward • TCC slip • Code P0741
Replace with Sonnax Part No.
37947-11K Requires 37947-TL11
Pressure Regulator Valve
• Delayed engagement • Poor shift quality
• Low/High line pressure • Overheating Reverse Modulator
• Low cooler flow at idle Valve, Outer
Replace with Sonnax Part No. • Delayed Reverse
37947-05K Requires 37947-TL5 • Burnt Reverse band
37947-54 (OE size) • Direct Clutch burned
• No Reverse
Replace with Sonnax Part No.
Reverse 37947-52
Modulator
Valve, Inner
• Delayed Reverse
• Burnt Reverse band TCC Regulator Valve
• Direct Clutch burned • TCC Regulator Sleeve • Code 628, 1741
• No Reverse • TCC surge • TCC apply concerns
Replace with • TCC cycling • High TCC slip RPM
Sonnax Part No. • Overheated fluid • Overheated converter
37947-53 Replace with Sonnax Part No.
37947-09K Requires 37947-TL9

Coast Clutch Valve

• No engine braking in D3 to low
• No 4th, 2nd or 5th (4R44E/55E)
• No coast clutch apply
Replace with Sonnax Part No.
37947-33K Requires 37947-TL33

To vacuum test this port:

invert valve and prop outboard
with a Torlon checkball.

TCC Modulator Valve

• Code 1741 • No lockup • Low cooler flow
• Engine stall on FWD engagement
• Poor converter fill & delayed engagements
Replace with Sonnax Part No.
37947-07K Requires 37947-TL5

*Part numbers with an asterisk (*) are included in this Zip Kit. Other part numbers are available separately.

©2019 Sonnax Transmission Company, Inc. • A Marmon / Berkshire Hathaway Company 4R44E-5R55E-ZIP-Booklet_C 12-09-19

800-843-2600 • 802-463-9722 • F: 802-463-4059 • www.sonnax.com Page 7
 FORD 4R44E, 4R55E, 5R44E, 5R55E ZIP KIT® Installation & Testing Booklet

OE & Sonnax Reinstallation Valve Body Exploded View

Valve Body Descriptions Sonnax Parts

I.D No. Description 102 NOTE: Sonnax replacement

parts are boxed and in blue
Forward Engagement 103 in this diagram.
101
Control Valve
There are six “L” pins in this
Boost Valve Assembly OE valve body. Sonnax gives
102
& Pressure Regulator Valve you two new “L” pins in this
Zip Kit to replace any that
EPC Boost Valve may be damaged.
103
& Forward Modulator Valve
104 Manual Valve
105 Reverse Modulation Valves 104
106 2-3 or 3-4 Shift Valve
107 1-2 or 2-3 Shift Valve 101
108 Solenoid Regulator Valve
Coast Clutch Valve
109
& Converter Regulator Valve
Converter Clutch
110
Modulator Valve
Cooler Limit Valve, Bypass Valve
111
& Thermostat Bypass Valve
112 3-4 or 1-2 & 4-5 Shift Valve
113 Throttle Downshift Control Valve
114 Manual Low Valve
115 Kick Downshift Control Valve

115 105

114 106

113 107

108
112

109
110
111

12-09-19 4R44E-5R55E-ZIP-Booklet_C ©2019 Sonnax Transmission Company, Inc. • A Marmon / Berkshire Hathaway Company

Page 8 800-843-2600 • 802-463-9722 • F: 802-463-4059 • www.sonnax.com