Symptoms:

  • 3-4 Flare
  • Ratio codes
  • 4-5-6 Clutch burned
  • Slipping gears
  • 3-4 Harsh

Cause:

Wear at the accumulator piston bore or on the critical diameter of the accumulator piston allows clutch apply oil to exhaust.

Correction:

Recover hydraulic control and renew shift feel and performance by installing Sonnax 4-5-6 accumulator piston kit.

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

4-5-6 Accumulator Piston Kit
Part No. 124740-57K

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

Excess wear at the accumulator bore or on the critical diameter of the accumulator piston is common in GM Gen. 2 6T70, 6T75 and 6T80 transmissions. The 4-5-6 accumulator piston is utilized during apply of the 4-5-6 clutches to smooth engagement. Wear at this bore allows 4-5-6 clutch apply oil to exhaust, resulting in ratio codes, harsh or delayed application of the clutch pack, burnt clutches and slipping/flares. Installing Sonnax 4-5-6 accumulator piston kit 124740-57K eliminates leaks to restore normal shift operation and feel.

  • O-Ring incorporated for positive sealing, even in worn bores
  • Annular grooves help center piston in bore to reduce future side-load wear
  • Hardcoat anodized aluminum piston combats premature wear

  • Piston
  • O-Rings (2) 1 Extra
  • Spring Small
  • Spring Large
  • 124740 57k combo
  • 124740 57k

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 57k test