Symptoms:

  • Clutch & band failures
  • Loss of lube oil
  • Low line pressure
  • High line pressure
  • Soft shifts
  • Harsh shifts
  • Low converter pressure

Cause:

Continuous oscillation of pressure regulator valve results in excess bore wear, causing erratic line pressure and/or restricting converter feed oil.

Correction:

Recover hydraulic control and renew line pressure performance by reconditioning the bore and installing Sonnax oversized pressure regulator valve kit.
  • 4F27E, FN4A-EL, FNR5, FS5A-EL Oversized Pressure Regulator Valve Kit 46892-01K
  • 4F27E, FN4A-EL, FNR5, FS5A-EL Oversized Pressure Regulator Valve Kit 46892-01K

You need this if...

Vacuum test(s) at the port(s) indicated fail to hold the recommended minimum in-Hg.

4F27E, FN4A-EL, FNR5, FS5A-EL Oversized Pressure Regulator Valve Kit Vacuum Test Locations