Symptoms:

  • Shift quality is not load sensitive
  • Harsh shifts
  • Slips & flares
  • Delayed engagement
  • Burnt clutches
  • Slide shifts
  • Slip codes

Cause:

Wear in clutch boost valve bores cause feedback pressure instability, preventing normal shift operation.

Correction:

Recover hydraulic control and renew shift performance by reconditioning the bore and installing Sonnax oversized clutch boost valve.

6T70 (Gen. 2), 6T75 (Gen. 2), 6T80 (Gen. 2)

Oversized Clutch Boost Valve
Part No. 124740-56

Fits any of three locations.


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

GM Gen. 2 6T70, 6T75 and 6T80 clutch boost valves provide feedback pressure to their respective clutch regulator valves, balancing the regulators to assist with apply and release of the associated clutch. Pressure control solenoid fluid acts on the boost valve to precisely control the amount of oil delivered to the balance end of the clutch regulator valve.

Excess wear in boost valve bores can result in harsh shifts, slipping, burnt clutches, flares, and delayed engagement. Reconditioning the bore and installing Sonnax oversized clutch boost valve 124740-56 restores the hydraulic control necessary for trouble-free shifting.

  • Hardcoat anodized aluminum valve combats premature wear
  • Oversized valve engineered to perform to OE specification

Proper operation of clutch boost valves depends on correct pressure being supplied by shift solenoids. If trouble is found with pressure supply to these solenoids, Sonnax offers oversized AFL/solenoid regulator valve 124740-48K.

  • 6T70 (Gen. 2), 6T75 (Gen. 2), 6T80 (Gen. 2) Oversized Clutch Boost Valve 124740-56
  • 6T70 (Gen. 2), 6T75 (Gen. 2), 6T80 (Gen. 2) Oversized Clutch Boost Valve 124740-56

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.

  • 6T70 (Gen. 2), 6T75 (Gen. 2), 6T80 (Gen. 2) Oversized Clutch Boost Valve Vacuum Test Locations