Excess wear at the accumulator bore or on the critical diameter of the accumulator piston is common in GM Gen. 2 6T70/75/80 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. Sometimes this wear can be addressed by installing Sonnax 4-5-6 accumulator piston kit 124740-57K. However, the casting is subject to severe wear at this location which can be beyond the ability of the non-sleeved 124740-57K kit to address.

Installing Sonnax 4-5-6 sleeved accumulator piston kit 124740-68K provides a positive sealing O-ringed sleeve to eliminate oil leaks and restore normal shift operation and feel, even in the most severely worn bores.

• O-ring incorporated for positive sealing, even in worn bores
• Sleeve manufactured from highly wear-resistant aluminum
• Annular grooves help center piston in sleeve to reduce future side-load wear
• Hardcoat anodized aluminum piston combats premature wear
• Drop-in Zip Valve™ parts install quickly and easily