A904 (TF6), A500, 42RE, 42RH

Symptoms:

• Converter shudder & failure
• TCC lockup surge
• TCC deflection & lining failure
• Planetary failure
• Cooler restriction

Cause:
Insufficient control of apply and release oil circuits results in high converter apply pressure and deflection of the lockup piston.

Correction:
The redesigned Sonnax control valve improves TCC solenoid control over the apply rate, reducing EMCC cycling

Not for use with #33 separator plates. Can be used with all later designs.

High TCC apply pressures in the listed Chrysler units cause the TCC (lockup piston) to deflect or balloon. This occurs because of insufficient control of apply and release oil circuits. This apply pressure spike causes a chain reaction of events. The TCC deflection causes converter failure, sending TCC friction lining material through the transmission. This can restrict the radiator, cause lack of lube, planetary meltdown or total unit failure. Often the unit may be overhauled and a repeat planetary failure could result from an undetected restricted cooler. Other complaints are converter shudder, or TCC lockup surge between 35 to 40 mph. The redesigned Sonnax TCC control and plunger valve kit regulates TCC apply and release oil.

• Valve kit is compatible with all controllers
• Control valve is designed with an undersized middle spool that acts like an orifice to control flow entering the converter
• Once flow passes through the middle spool, apply pressure is controlled by the internally regulated control plunger

Kit Contains:

• Control Valve
• Control Plunger

SONNAX Installation Instructions