Symptoms:

  • Delayed engagement
  • Loss of lube oil
  • TCC apply & release concerns
  • TCC codes
  • Burnt clutches
  • Harsh shifts
  • Slipping gears
  • Soft shifts
  • Solenoid performance codes
  • Wrong gear starts

Cause:

Wear in solenoid regulator valve bore causes erratic supply pressure to control solenoids. Wear in TCC relief bore results in improper lube supply and TCC control problems.

Correction:

Recover hydraulic control, renew shift and TCC operation by reconditioning the bore and installing Sonnax oversized solenoid pressure regulator or converter relief valve.
  • 4F27E, FN4A-EL, FNR5, FS5A-EL Oversized Solenoid Pressure Regulator or Converter Relief Valve 46892-03
  • 4F27E, FN4A-EL, FNR5, FS5A-EL Oversized Solenoid Pressure Regulator or Converter Relief Valve 46892-03

You need this if...

Vacuum testing at the port(s) indicated fails to hold the recommended minimum in-Hg, or if wear is visually detected.

4F27E, FN4A-EL, FNR5, FS5A-EL Oversized Solenoid Pressure Regulator or Converter Relief Valve Vacuum Test Locations
4F27E, FN4A-EL, FNR5, FS5A-EL Oversized Solenoid Pressure Regulator or Converter Relief Valve Vacuum Test Locations