VBFIX-logo-web details-chart-web video-logo-web printlink SERVOFIX-logo-web r_and_r_only maillink sonnax-black Facebook-color Twitter-color LinkedIn-color Youtube-color


  • Harsh shifts
  • Soft shifts
  • Solenoid performance codes


Bore wear can cause excess leakage in the actuator feed limit circuit which can affect solenoid function resulting in various drivability issues


Restore hydraulic control by reconditioning the bore and installing Sonnax oversized accumulator pistons.

6T70 (Gen. 1), 6T75 (Gen. 1)

Oversized Actuator Feed Accumulator Piston Kit
Part No. 124740-40K

You need this if... View Instructions

GM 6T70 (Gen. 1) and 6T75 (Gen. 1) units often suffer shift abnormalities caused by excess wear in the actuator feed accumulator piston bores. This wear allows actuator feed limit fluid loss which prevents proper regulation of oil pressure supplied to control solenoids, resulting in harsh or soft shifts, solenoid codes and clutch failure.

Reconditioning the bore and installing Sonnax oversized actuator feed accumulator piston kit 124740-40K re-establishes correct clearance for revived shift control in all ranges.

  • Hardcoat anodized aluminum valve combats premature wear
  • Spring calibrated to match OE function
  • Accumulator Pistons (3)
  • Springs (3)
  • 124740 40k combo
  • 124740 40k

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.

  • 124740 40k in test