32 GEARS August 2005

W elcome back to Q&A:Weve gathered a fewmore questions that havecome through the ATRA TechnicalDepartment and wanted to share theanswers with you. Once again, thenames and towns have been changed toprotect the innocent.

4R44E/5R55E:Converter Clutch Slip

Hi, my name is Chris and Im arebuilder from Mooresville, NorthCarolina. Weve been fighting a TCCslip code in a 1995 Ford Ranger with a4R44E. Weve installed two differentused valve bodies, a new solenoid, andthree rebuilt torque converters. We alsoinstalled a new pump from the localFord dealer and the input shaft looksgreat. I read your Q&A article in theJuly 2004 issue of GEARS Magazineand was impressed by the information

that was written about the F4E-III lock-up system. Is there anything else that Ican do to improve lockup in the4R55E/5R55E and get rid of this code?

Well, it wouldnt be right if I didntask how line pressure looked. For now,Im going to assume its good. Withthat said, there are only a few thingsyou didnt mention.

First, make sure you have the cor-rect TCC solenoid installed (figure 1).95-96 models must use part # F5TZ-

7F037-AA; 97-up models must use part# ZL2Z-7G136-AA. Electrically, thesesolenoids appear to be the same. Buthydraulically they respond differentlyto the duty cycle signal the computersends during lockup. For example, ifyou install a late TCC solenoid in a 95Ranger, the pressure the TCC solenoidproduces wont ramp up quicklyenough to engage the converter clutchproperly. This is because the 95 Rangercomputer signals are calibrated for the

by Larry Frash

Figure 1

97-Up ModelsPart# ZL2Z-7G136-AA

Always use assembly grease in the springpocket to prevent the spring from popping outduring assembly.

Converter clutch modulator valve.

95-96 ModelsPart# F5TZ-7F037-AA

Figure 2

frash-Q-A.qxd 7/22/05 2:17 PM Page 32

early designedTCC solenoids andnot the late style.

During lock-up, converterclutch release oilmust be exhausted.The problem withthis transmission isthe converterclutch release pres-sure exhauststhrough the spring-loaded cooler limitvalve. This pre-vents release pressure from droppingcompletely to zero like most othertransmissions.

Heres a very simple modificationthat will improve lockup: Remove the converter clutch mod-

ulator valve (figure 2). Drill a 0.062 exhaust hole in the

converter release passage of thevalve body casting (figure 3).

Plug the small bypass hole in theplate (figure 4).This will completely exhaust the

converter release circuit when the con-verter clutch modulator valve is in thelockup position. Dont forget to plugthe small bypass hole in the plate.Failing to do so will create a converterdrainback condition.

When you reinstall the converterclutch modulator valve, make sure youput some assembly grease in the springpocket of the valve. If the spring popsout during assembly, it willl cock in thebore and prevent the valve from mov-ing.

This modification is a quick, easy

way to improve lockup and can be usedas a rebuild procedure on all4R44E/5R55E transmissions.

R4AEL: Falls Out ofOverdrive

My name is Eddie, and Im fromthe Atlanta area. Im working on a1990 Mazda MPV with anR4AEL transmission thatdownshifts to third gear whenI let off of the accelerator.Line pressure was good and4th apply pressure dropped tozero during the downshift, soI thought it was a controlproblem. I monitored the shiftsolenoid signals and foundthat, when I was cruising in4th gear at about 60 MPH,solenoid A was on and sole-noid B was off. When I let offthe accelerator, nothingchanged. But then I noticedthe overrun solenoid wascycling on and off with theaccelerator pedal. When the

GEARS August 2005 33

Drill a 0.062" exhaust hole in this circuit. The hole should protrude through the outside of the casting.

When doing this modification, always plug this hole.

TCM

Figure 3

Figure 4

Figure 51990 MPV Inhibitor Switch Circuit

Please visit us atbooth #727

frash-Q-A.qxd 7/22/05 2:17 PM Page 33

overrun solenoid was on, I had 4th

gear. Can this cause this transmissionto fall out of 4th gear, and is this nor-mal? I also noticed that the hold modeindicator light doesnt work.

Eddie, so far youve done a fantas-tic job diagnosing this problem and itled you in exactly the right direction.The overrun solenoid must be on tohave 4th gear. At light throttle, the over-run solenoid controls the overrun clutchcontrol valve, which can inhibit 4th

gear and apply the overrun clutch. Theoverrun solenoid should stay on whenyou lift your foot off the accelerator.

Three weeks ago I had a similarcall. What was causing these two symp-toms was no voltage to the inhibitorswitch. The computer strategy wontallow Hold Mode to work in park, neu-tral or reverse, so believe it or not, theHold Mode indicator not working was abigger clue than you may have thought.

The inhibitor switch supplies 12volts to individual pins on the comput-er, one for each gear, depending onwhat gear you select (figure 5). Forexample, in reverse, the computerreverse indicator pin would receive 12volts from the inhibitor switch and allother pins from the switch wouldreceive zero volts.

Apparently, when none of thesepins have power, theres a computerstrategy that allows the transmission towork normally unless you let off thethrottle in 4th gear or request the HoldMode function. Check for power to theinhibitor switch. If you have power to it,backprobe the computer using the com-puter pin chart (figure 6) to see if theinhibitor switch is working properly.

CD4E RepeatConverter Failure

Hi, my name is Roger; Im working

on a 1998 Ford Contour witha CD4E transmission. Thiscar keeps coming back withconverter slip codes. Sofar Ive had the converterrebuilt four times. Iveinstalled a brand new valvebody, new solenoid pack,new pump, new stator sup-port, and checked the inputshaft. Ive also verified thecomputer is correct and thetransmission has the correctratios. I cant see anythingwrong with this transmission.Please help.

Roger, sometimes theanswer is in places that atransmission rebuilder sim-ply cant see. Whether yourehaving lockup problems ornot, always check converterturbine pressure (figure 7).With the transmission hot,the pressure should be atleast 70 PSI while the trans-mission is in lockup. Lowconverter turbine pressurewill cause converter slip.

While most converterrebuild companies are verygood, sometimes they mayoverlook things like acracked piston. Its commonfor these converters to havecracks in the apply pistons(figure 8).

The transmission thatthis converter came out of had good tur-bine pressure until the transmission gothot. When the transmission temperaturereached about 150 F, the turbine pres-sure dropped to 25 PSI in lockup.Replacing the converter cured both thepressure problem and lockup problem.Have the converter rebuilder cut your

converter open and check the apply pis-ton yourself for small cracks.

If you or anyone in your shop havetechnical questions or have a fix of yourown, send them in wed love to hearfrom you!

34 GEARS August 2005

Q&A: 3 Hot Tech Problems and Answers

Figure 6

Figure 7

ConverterTurbinePressure

CD4E converter clutch apply pistonsusually crack in this location.

Figure 8

Automatic Drive P.O. Box 440Bellows Falls, VT 05101-0440 USA800-843-2600 802-463-9722 F: 802-463-4059www.sonnax.com info@sonnax.com VISIT OUR WEBSITE FOR SONNAX REAMERS & OTHER TOOLS

See your nearest Transmission Specialties distributor & ask for Sonnax quality engineered products.

2005 SonnaxD E S I G N E D T O S A V ETM

COMPLAINT

Severe wear of the valve body boreat the bypass clutch control valveallows regulated converter chargeoil leakage.

These valves are slightly oversizedto restore hydraulic integrity atthe spool/bore interfaces.

Oversized BypassConverter ClutchControl Valve Kit

96201-19KOversized Bypass Converter Clutch Control Valve Kit

1 O.S. Bypass Clutch Control Valve1 Spring

96201-TL1 Reamer1 Reamer Jig1 Bore Sizing Tool

Also Available96206-01KBypass Clutch Control Plunger Valve & Sleeve

COrrection

Cause

Converter clutch apply andrelease problems are commonin AXODE and AX4S transmis-sions with severely worn valvebody bores at the bypass clutchcontrol valve. A worn bore canallow converter feed and lubeoil to exhaust, causing a loss ofMCCC (modulated converterclutch control) solenoid control.The Sonnax kit includes awear-resistant, oversized valve

to restore hydraulic integrity atthe spool/bore interface, alongwith a sturdier spring for thecontrol sleeve to offer strongerresistance to the oversizedvalve. Annular grooves havebeen added to the TCC sole-noid spool lands to help centerthe valve in the bore. A boresizing tool is included to ensureproper fit and bore integrityafter reaming.

TCC apply & release control problemsSECONDARY COMPLAINTs Hydraulic-related converter codes Reduced cooler and lube pressure

OApply yourself

The new Sonnax Oversized Bypass Clutch Control Valve Kit for the AXODE and AX4S can save you up to

$200 in valve body replacement costs.

REQUIRE

D

TOOL

REQUIRE

D

TOOL

Bypass Converter Clutch Control Valve

Bypass Control Plunger Sleeve(also available 96206-01K)

Spring

Reamer

Jig

Bore Sizing Tool

Bypass Control Plunger(also available 96206-01K)

Retaining Clip

AXODE, AX4S

sonnax plcd 8-05.qxd 7/21/05 4:41 PM Page 35

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Job Name: Job Number: Proof Due: Thu, May 19, 2005Final Due: Thu, May 19, 2005Company: ATRA - GEARSContact: Jeanette TroubAddress: 2400 Latigo Ave are you really reading this?City: heheheheState: insanity Zip: Country: Office Phone: 805-604-2016Email: JTroub@atra.comNotes: Do all these files look the same?