Sonnax Ford Info from Bob

Sonnax Ford Info from Bob Sonnax :The following information is compiled from post-rebuild drive-ability complaints, which may or may not be related to the converter ..

Converter Related "Tech"
by Bob Warnke

These Domestic unit complaints are categorized by vehicle application:

Daimler/ Chrysler, GM & Ford

Example: 670-1 identifies the transmission.

At as first correction:

• A,B,C, place the complaint in an order.

• "t" notes a concern as transmission related, c = converter related , v =vehicle related.

Compiled for Sonnax and Rebuilders by Bob Warnke, from Tech. calls and recorded sources. Rev. 05-15-02

Ford Converter Conditions



• TCC comes on and stays on, after 1-2 shift


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

• Bt: TCC solenoid defective



• TCC cycling on-off-on, often mis-diagnosed as slip in 4th gear.


• Av: Defective RPM sensor, FIPL or TPS

• Bv: Inspect battery voltage and voltage drops across ground

• Cv: Inspect brake switch and brake light circuit for intermittent swith function or ground problems.



• Engine stall forward or reverse


• Av: Defective MLPS or wiring

• Bt: Pump has excessive warpage and cross leakage. Excessive clearance causes low output and engine stall at idle.

• Ct: Plugged turbine shaft support bushing oil flow. Bushing installed too deep or mixed stator and pump cover will reduce release oil flow.

• Dc: Defective converter piston seals or piston run-out/clearance



• Code 62, repetative, or under heavy use

Correction :

• Ac: Cracked TCC piston

• Bc: Excessive converter cover run-out or piston run-out. Suggest Sonnax heavy cover for diesel applications.

• Ct: Insufficient converter apply psi; poor/ low converter regulator spring

• Dt : Upgrade to the F5 or latter casting # high capacity pump

• Et: Insure filter is flowing well

• Fv: Install high capacity cooler lines and radiator

• Gt: Be careful with pump, lube and pressure reg. modifications! Excessively large line to lube holes will reduce line psi. and increase drainback.

• Hc: Suggest clearance of .025"-035" between turbine and cover after weld



• Repeated converter hub bushing failure and front seal leakeage.


• Av: Vehicle was operating under FMEM ( High line psi.) conditions for extended time.



• TCC rattle at idle, Engine stall after coast to stop after TCC applied, No TCC apply


• Ac: Grobe clutch plate lugs often lodge themselves into the cover and stick. This wear either holds the piston applied or does not allow the cluth to apply.



• Code 628 after rebuild


• At: Wrong planetary gear ratio, an AODE set used instead.



• TCC shudder, No TCC apply, Code 628


• At: First step is to change fluid to Chrysler 7176 or Mercon 5

• Bt: Install a new converter by-pass control sleeve Sonnax # 76948-04K

• Ct: Inspect the bore at the TCC by-pass valve largest diameter spool area.

• Dt: Install the updated TCC modulated solenoid

• Ec: Verify friction is not glazed and TCC piston taper does not exceed .0017 per inch

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


Complaint :

• TCC slip, no TCC. TCC cycling fluid overheat


• Av: Bypass tube stuck open or by-passing too much flow.


Complaint :

• TCC stalls motor after transmission service/rebuild


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

• Bv: Aftermarket TCC control defective, shorted and applying TCC

• Ct: Installing too strong of a pressure regulator spring can cause this condition.


Repeated complaint :

• Front seal leak, ballooned converter, engine crank thrust failure


• At: Excessive converter regulator pressure

• Bt: Re-spring converter regulator valve



• TCC apply on 2 nd gear, causing harsh 2 nd & TCC, poor acceleration


• At: TCC control check ball, (#7) is missing, MCC solenoid feed psi excessive, worn by-pass valve bore, bypass sleeve hole is too small, open to 1/16 (.062")



• No TCC, TCC chuggle on coast-down


• Av: No power to center terminal on case connector (fuse etc.). No ground supplied by the ECU. Suggest supplying own power and making ground circuit at the TCC solenoid to verify valve body operation

• Bt: Case connector diode burned out

• Ct: Mismatched separator plate to valve body. On the #1 solenoid valve body, some plates take TCC filter some do not. Plates that require filter, go with body that has a channel cut across TCC sold.

• Dt: Poor governor circuit oil rings or case bore leaks

• Et: Suggest using the OE TCC solenoid with 2 holes in snout

• Ft: TCC shuttle valve spring too strong or bore worn = late or no apply

• Gt: TCC shuttle spring too weak = premature lock-up.

• Ht: Chuggle on deceleration is affected by the spring on the TCC shift valve under the 4th solenoid. See Sonnax # 56995A

• It: Low pump volume and/or worn pressure regulator bore.



• TCC shudder on apply and release, may not set code 1740/741


• Ac: Remove the multi-plate TCC piston and install single

• Bv: Shudder on apply may be corrected by re-flashing controller and changing fluid. Use Mercon 5 &/or Lube Guard Black

• Cc: Turbine to piston splines stripped, turbine seal leaking or piston contact worn

• Dt: Verify the latest Torlon or Peak butt cut stator seal is installed.

• Ev: This converter slippage is aggravated by poor line rise. Test MAF, clean it and insure output voltage exceeds 3.4 volts at W.O.T.

• Ft: If the 741 code exists with new valve body & new pump. Perform the valve body modifications to increase TCC release. (Sonnax info)



• Engine stall on engagement, repeated pump bushing converter hub failure


• At: Pump output too low, use updated OE new pump #____________

• Bt: Open up to converter release (line-lube) hole in separator plate (see Sonnax nformation)

• Ct: O-ring seal omitted from inner pump gear

• Dt: TCC control valve installed backwards or stuck



• No TCC apply


• At: Seal up the valve body end plugs, repair the drain-back check -valve pockets, replace the by-pass control sleeve with Sonnax #96201-06K

• Bt: Test TCC solenoid for sealing with 12 volts

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



• Code 628/1744, No TCC


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

• Bt: Comparable situation with improper sprocket ratios

• Ct: Turbine sensor coil to reluctor clearance excessive (should be .050")



• Poor converter fill, low pressure


• Ac: Poor cover alignment will gaul the oil pump shaft sealing rings

• Bt: Restricted oil pump shaft

• Cv: Dowel pins worn allowing transmission to sag, wearing pump bearing, sleeve and pump shaft



• TCC applies at 2nd gear shift

• TCC does not disengage, coast down chuggle


• Av: Installing the wrong TCC solenoid or separator plate combination without matching ECU/ controller. The gray case connector identifies unit with PWM/TCC solenoid and it's matching separator plate. The white connector identifies unit with on-off TCC solenoid and plate. (90-92 is problem area)

• Bt: Check ball missing or gone through the separator plate



• Code 628, No TCC feel of apply slippage

• TCC chuggle on deceleration


• At: Oil pump shaft restricted or loose internal tube, pump shaft seal leakage next to bearing

• Bt: Defective MCCC solenoid

• Ct: Worn valve body at by-pass control valve (see sag test specifications to test) sag detection not to exceed .023"

• Dt: Worn By-pass control sleeve (Wear here is common to no RPM change during TCC command by ECU and coast down chuggle as by-pass valve does not want to return. See Sonnax # 96206-03

• Ev: Turbine sensor (channel plate near axle) clearance excessive (not to exceed .050")

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



• Code 628/1744, engine will not pull down with TCC solenoid applied, no TCC apply


• Ac: Cracked TCC piston, leaking piston to turbine seal, worn turbine hub & restricted flow of CBY oil

• Bt: 6 Cyl. turbine hub with a 4 cylinder turbine shaft

• Ct: Excessive valve body bore wear. Sonnax offers two valve body repair kits for the CD4E, #73840-RK and BK

• Dt: Excessive transmission bushing wear, poor pump volume, poor quality aftermarket pump plate. Remember to align pump & add additional ground straps!

• Ev: Very important to test CT pressure! This test identifies hydraulic, valve control pump and busing condition. (see Sonnax Tech article or Sept. 01 Trans Digest

• Fv: Wrong sprocket ratios for PCM

• Gv: Incorrect turbine speed sensor or reluctor to sensor gap excessive, if problem started after trubine sensor replacement

• Hc: Converter rebuilders have reported success with red Ford imprinted lining or flat lining bonded to piston. Either strip off OE lining from cover &/or stiffen OE lining backing plate, or weld in new backing disc into cover


• TCC slip codes


• At: Worn pump stator bushings at Turbine shaft.