Symptoms:

  • Low line pressure
  • Various shift concerns
  • Delayed engagement
  • Poor shift quality
  • Burnt clutches
  • TCC apply & release concerns

Cause:

Wear in the bore and valve at the outboard spool area can allow line pressure signal oil to cross-leak to the exhaust. This prevents proper hydraulic control of the pressure regulator and reduces line pressure.

Correction:

Restore proper hydraulic control by replacing worn parts with a Sonnax drop-in main pressure regulator valve kit with extended front land to restore proper clearances and flow by operating in unworn areas of the bore.

10L80, 10R140, 10R80

Main Pressure Regulator Valve Kit
Part No. 105740-12K

Does not fit 10L80 Gen. 2 units.

You need this if... View Instructions Find a Distributor

Wear in the main pressure regulator bore and on the outboard spool area of the valve is common in GM 10L80 (Gen. 1) and Ford 10R80 and 10R140 transmissions. This wear minimizes line pressure control resulting in delayed shift engagement, poor shift quality and burnt clutches. Wear at the inboard spool and bore can lead to converter apply issues.

Installing the drop-in Sonnax main pressure regulator valve kit 105740-12K eliminates the leakage of line pressure signal oil to exhaust with the incorporation of an extended front valve spool. This valve spool is 270% longer than the OE spool, so actuates in unworn areas of the bore. The O-ringed end plug provides a positive seal and prevents critical signal fluid from leaking to exhaust. Both of these Sonnax features ensure your units will have proper line pressure control through all drive ranges.

  • Extended outboard spool is 270% longer than OE and actuates in unworn areas of the bore
  • O-Ringed end plug provides positive seal to prevent critical signal fluid from leaking to exhaust
  • Hardcoat anodized aluminum valve combats premature wear
  • Drop-in Zip ValveTM parts install quickly and easily

Learn More About Zip Valve™ Drop-In Repairs
  • Valve
  • End Plug
  • O-Rings (2) 1 Extra
  • Spring
  • 10L80, 10R140, 10R80 Main Pressure Regulator Valve Kit  105740-12K
  • 10L80, 10R140, 10R80 Main Pressure Regulator Valve Kit  105740-12K

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.

10L80, 10R140, 10R80 Main Pressure Regulator Valve Kit  Vacuum Test Locations