by ed lee and maura stafford - the torque converter ... ed lee and maura stafford ... e4od pump —...

Are TransmissionProblems Causing Your

Converter to Fail?By Ed Lee and Maura Stafford

There are many transmission-related problems that candirectly affect the functioning and longevity of the torqueconverter. If these problems are misdiagnosed, the con-verter can be blamed. Even worse, if the transmissionproblem is not corrected, repeat converter failure canoccur. Some transmission-related problems that can bemanifested as converter problems include:

• Restricted coolers

• Worn or wrong pumps

• Worn or stuck valves

• Worn bushings

• Incorrect fluid

• Bad solenoids or sensors

• Pressure problems

800-843-2600 • 802-463-9722 • fax: 802-463-4059 • www.sonnax.com • [email protected] 1

© 2004 Sonnax

Ed LeeThe Wheelman

• Sonnax Technical Adviser

• Owner/operator of Deltrans Inc. transmission shop since 1982

• Charter member of the TASC Force™

• Seven years ago started TASC Force Tips column in TransmissionDigest and continues to contribute articles

2 800-843-2600 • 802-463-9722 • fax: 802-463-4059 • www.sonnax.com • [email protected]

Are Transmission Problems Causing Your Converter to Fail?

Maura StaffordThe Desk Jockey

• Project Engineer with Sonnax for more than 10 years

• Currently works out of a home office in Georgia

• Primary design work is developing Transmission Specialties®products

• Actively involved with the TASC Force™ since its inception

• Technical articles have been published in Transmission Digest andGears magazines

1-800-274-7890

• Converter shops are entitled to a free subscription to Transmission Digest.

∑• This monthly publication has many technical and

managerial articles, industry news, new product announcements and company profiles.



Sonnaflow™

Diagnostic Tool

• Sonnaflow™ is a machine that measures and records cooler flow

• Important diagnostic tool

• Instrumental in the development of many of the TASC Force™ solutions

The Sonnaflow™ offers these unique features:• Can measure flow during a vehicle road test

• Provides an easy-to-read electronic display in gallons per minute

• Easy to install and remove from any vehicle

• Reduces warranty comebacks. Can pay for itself by identifying just one cooler problem

• Helps detection of blocked coolers

• Helps prevention of burned planetary or bushing failures

• Easier and more accurate than traditional (1-quart-in-20-seconds) measurement method

• Superior to bulb-style glass tube-flow meters: no bulky hoses, quicker to install, more accurateover a wider range of temperatures and viscosity changes

• Can be used with a dynamometer to measure flow and pump output

• Can easily be connected to a lab scope

• Detects subtle variations in flow that cannot be detected with other test methods

• Also a great teaching aid!





Basic Test SequenceNote: Any testing while the vehicle is moving should beperformed with two people for safety reasons. One personmust remain focused on safe operation of the vehicle. Thesecond person can monitor and record the Sonnaflow™measurements.

Observe the Flow Rate during the following 3Basic Operating Conditions:

Idle

This is the same test as the traditional 1-quart-in-20-sec-onds measurement. Observe the flow with the vehicle atidle in drive range with the brake applied.

The flow at idle should be the lowest flow rate of the 3conditions with a minimum flow of 0.7 to 0.8 GPM. Somevehicles may have lower idle rates. Cold ATF may alsocontribute to lower idle flow rates. Recheck the flow whenthe ATF is warm.

In-Town Driving

Observe the flow while driving the vehicle at low to mod-erate speeds with your foot on the gas (not coasting). Thisis a TCC off or no-lockup condition.

The flow during in-town driving conditions should beconsiderably more than at idle (approximately double).

Highway Driving (Lockup)

Observe the flow while driving the vehicle in highwaycruising or other lockup conditions.

During lockup conditions the flow should show a notice-able variation from the in-town flow. The flow will normal-ly increase during lockup but may decrease on some vehi-cles. In either case the change should be noticeable.

Note: Some vehicles are not equipped with a TCC andnever achieve lockup conditions — therefore, this 3rdoperating condition cannot be measured.

Diagnosis AProblem: No flow or low flow (less than 0.5 GPM) atidle –OR– No increase in flow during in-town driving.

Cause:

• Either problem is usually due to a flow restriction eitherinternal to the transmission or external to the transmis-sion

(e.g. blocked cooler). To help determine the cause andlocation of a flow restriction, follow the procedure below:

• Determine if the restriction is internal or external to thetransmission. Bypass the cooler and re-run the flowtest. If the flow does not increase, then the restriction isinternal to the transmission. If the flow does increase,then the restriction is external in the cooler or coolerlines.

• If the cooler is blocked, it should be disassembled andrepaired or replaced as needed. Note: In extreme coldweather a cooler blockage may be the result of gelledATF. Re-test when warm.

• If the flow restriction is internal to the transmission, thefollowing possible causes should be checked:

• Low oil level

• Clogged sump filter

• Mismatched pump parts

• A pressure regulator valve that is stuck in its bore

• High boost pressure

• Lockup valves that are stuck

• Plugged drainback fitting

Diagnosis BProblem: No flow change at lockup

Cause:

• Lockup is not occurring. Two potential problems shouldbe investigated:

• The electrical signal is not being sent to the solenoid(s)responsible for inducing lockup

• One of the valves related to lockup is leaking or stuck inplace

NOTE:

• Some vehicles do not go into lockup

• Some pulse width modulated (PWM) transmissionsexhibit only a small change in flow during lockup. Thisis common in Ford AODE and AXODE transmissions.The flow must be observed closely to detect the lockupcondition. Use of the optional output signal adapterwith a graphing lab scope can assist in detecting theflow change during lockup in PWM transmissions.

E4OD/4R100Transmissions

Complaint: Converter clutch crowding on reverse engagement

Cause: Generally low pump volume at low RPM

Excessive tolerance = low pump volume

Standards:1. Converter hub to inner gear: .004” maxradial2. Face to pocket: .001” min, .002” max3. Tip to tip: .0025” per side, .005” totalradial4. Outer gear to pocket" total radial .006”5. Pump housing flatness: .001”

The OEM pressure regulator valve shutsdown the cooler circuit in idle, or if there islow pump volume. Results can be converteroverheat and Code 62 problems. A commonindustry trick for “fixing” these problems isto drill a hole into the casting wall of thepump. This allows line pressure to feedlube and converter feed full time.

The downfall to this “fix” is that it alsoallows converter drainback, which can cre-ate delayed engagements.



E4OD Pump — Correct method for measuring outer gear to cavity clearance.

E4OD Pump — Casting wall drilled.

The Sonnax pressure regulator valve has anencapsulated check valve that allows full-timeflow to the cooler circuit, yet prevents convert-er drainback. An orifice has also been addedto use regulated line pressure to assist thebalance circuit in overcoming EPC pressure.



E4OD ConverterConditions

Complaint: TCC comes on and stays on after 1-2 shift

Correction: • Inspect vehicle wiring harness: brake or stop light may have been rewired

• TCC solenoid defective

Complaint: TCC cycling on-off-on, often misdiagnosed as slip in 4th gear

Correction: • Defective RPM sensor, FIPL or TPS• Inspect battery voltage and voltage drops across ground

Complaint: Engine stall forward or reverse

Correction: • Defective MLPS or wiring• Pump has excessive warpage and cross leakage• Plugged turbine shaft or mixed stator and pump cover• Defective converter piston seals or piston run-out/clearance

Complaint: Code 62, repetitive, or under heavy use

Correction: • Cracked TCC piston• Excessive converter cover run-out or piston run-out• Insufficient converter apply psi, poor converter regulator spring• Upgrade to the F5 or later casting # high capacity pump• Ensure filter is flowing well• Install high capacity cooler lines and radiator• Be careful with pump, lube and pressure regulator modifications• Suggest clearance of .025” - .035” between turbine and cover after weld

AX4N/AX4S/AXOD/AXODETransmissions

Complaint: Converter seal leak

Cause: • Insufficient drainback

• Seal composition

• Torque converter integrity

Correction: •Drill additional drainback holes. Suggested 2 holes (one at 3 o’clock and one at 9 o’clock)

•Do not use silicone seals. Use Viton® seals only.

• Install Sonnax FD-90-29G flanged hub into torque converter.

Complaint: • Possible lockup shudder

• Code P0741, P1728, P1744, or P0743

Cause: • Incorrect lockup solenoid

Correction: • Install correct solenoid



AX Series Converter ConditionsComplaint: AXOD — No TCC apply

Correction: • Seal up the valve body end plugs, repair the drainback check valve pockets, replace the bypass controlsleeve with Sonnax part 96201-06K

• Test TCC solenoid for sealing with 12 volts

• Defective oil pump shaft, loose inner tube or plugged with stator cap material

Complaint: AXODE/AX4N — Code 628/1744, No TCC

Correction: • High resistance ground. Repair grounds or add additional from ECU

• Comparable situation with improper sprocket ratios

• Turbine sensor coil to reluctor clearance excessive

Complaint: AXODE — Poor converter fill, low pressure

Correction: • Poor cover alignment, would gall the oil pump shaft sealing rings

• Restricted oil pump shaft

Complaint: AXODE — TCC applies at 2nd gear shift or does not engage; coastdown chuggle

Correction: • Installing the wrong TCC solenoid or separator plate combination without matching ECU/controller. Thegray case connector identifies unit with PWM/TCC solenoid and its matching separator plate. The whiteconnector identifies unit with on-off TCC solenoid and plate.

Complaint: AX4N — Code 628; No TCC feel of apply; TCC chuggle on deceleration

Correction: • Oil pump shaft restricted or loose internal tube

• Defective MCCC solenoid

• Worn valve body at bypass control valve or sleeve

• Turbine sensor (channel plate near axle) clearance excessive

• Poor ground circuits for the ECU create erratic/no TCC and high psi



4R44E/55E & 5R44E/55ETransmissions



Complaint: Converter seal leak

Cause: • Poor seal composition

• Bad pilot sleeve

• Misalignment

Correction: • Replace silicone seal with Viton® seal

• Replace pilot sleeve

• Check center line (transmission tomotor), if...

AODE/4R70WTransmission

Complaint: • Delayed or no lockup• Shudder condition• Converter code 628• Uncontrollable TCC

Cause: • When too much oil is routed to the plunger valve, the bypass valve has slow reaction from theMCC/TCC solenoid oil, delaying lockup. Excessive wear at the control sleeve allows regulated convertercharge oil to exhaust, resulting in no TCC apply conditions.

Correction: • Install Sonnax replacement control sleeve and plunger kit 76948-04K. The sleeve has a smaller feedorifice, allowing the bypass clutch control valve to properly stroke to the TCC apply position. Thematched sleeve and valve restore correct clearances for hydraulic integrity.



Complaint: • Delayed forward engagement

• Engine surge or stall at idle

• Converter shudder

Cause: • Low baseline pressure

Correction: • In 1996, Ford made a change to both the pressure regulator valve and the valve body casting. The valvespool locations were changed slightly, and the spool diameter controlling line to converter feed was stepped. This spoolstep, in conjunction with regulating notches added to the valve body casting, allows converter feed to be regulated. Dueto these OEM modifications, installation of a stronger spring to raise baseline pressure (ideally 68 psi) without a spe-cially modified regulator valve will result in restriction of converter charge and converter release circuits. This maycause the engine to stall or surge at an idle or create converter shudder.

The Sonnax kit 76948-12K contains a properly metered PR valve and stronger spring for ‘96-up valve bodies. Sonnaxspring 76948-06 can be used by itself in the ‘91-’95 valve bodies.

AODE/4R70W Converter ConditionsComplaint: 4R70W — Code 628 after rebuild

Correction: • Wrong planetary gear ratio, an AODE set was used instead

Complaint: AODE — TCC Shudder; No TCC apply; Code 628

Correction: • Change fluid to Chrysler 7176 or Mercon 5

• Install a new converter bypass control sleeve, Sonnax part 76948-04K

• Inspect the bore at the TCC bypass valve largest spool diameter

• Install the updated TCC modulated solenoid

• Verify friction is not glazed and TCC piston taper does not exceed .0017”

• Inspect stator support for wear at the TCC sealing rings or bushing

Complaint: AODE — TCC stalls motor after transmission work

Correction: • Pinched wire from transmission service or valve body work

• Aftermarket TCC control defective, shorted and applying TCC

Complaint: AODE — Front seal leak; ballooned converter; engine crank thrust failure

Correction: • Excessive converter regulator pressure

• Re-spring converter regulator valve



Chrysler RWDTransmission

Complaint: • Delayed engagement• Lube failure• No converter charge in park• Converter drainback• Converter bushing failure• Pressure regulator buzz

Cause: • Poor converter feed pressure due to OEM pressure regulator valve design

• OEM manual valve does not allow converter charge in park

Correction: • Install Sonnax Lube Regulated Pressure Regulator Valve, part number 22771A-02K

• Install Sonnax Manual Valve, part number 22771-09



Complaint: • Lockup shudder

• Overheated converter

• Reduced cooler flow

• Soft TCC apply

• Build up of release pressure during lockup

Cause: • The OEM 4-spooled switch valve stroke is insufficient to control circuit timing of applied vs. releasepressures.

Correction: • Install Sonnax modified 4-spooled switch valve, 22771A-01, which improves timing & flow to the applyand release circuits.





TASC Force Tech Tips Article, February 2004 Transmission Digest



Chrysler RWD Converter Conditions

Complaint: 42RE — No TCC after rebuild; slow converter fill or repeated lube failure

Correction: • Mismatched pump halves with large and small suction ports

• Mismatched large suction port case with small port valve body

• Switch valve stuck open towards spring

Complaint: 42RE — Delayed engagement together with ballooned converter

Correction: • Worn pressure regulator reducing valve, aggressively drilled line-to-lube

Complaint: 47RE — Rapid or repeated converter friction failure; soft TCC; no TCC apply or clutch not releasing

Correction: • Bond lining where OE was floating

• Alter converter stall on diesel units

• Adjust line to 80 psi (idle drive) install Sonnax switch valve

• Verify cooler flow minimum is .7 gpm idle in drive, 1.6 gpm TCC off cruise and 1.8-2.1 gpm TCC applied

• Install a quality Teflon® seal on the turbine shaft

• Verify the turbine-to-cover bushing/bearing is centering the turbine

• Resurface the pump stator, and recess the bolt holes in pump body

• Set up pump pocket to gear side clearance at max of .0015”

• OE had some turbine shafts with feed hole too small, inspect for update



Complaint: 47RE — Sensitive TCC in-out

Correction: • Defective TPS, suggest automatic replacement after 50K

• Open the exhaust slot in the separator plate

Complaint: 47RE — TCC stalls engine in reverse

Correction: • Verify cooler flow is not restricted

• Problem generally related to release oil flow. Open the exhaust circuit outer circuit of switch valve

• Reseal the turbine shaft rings at the stator, air check of input shaft

• Ensure oil flow of release circuit in the converter is not restricted

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