Order Status & Returns
Gift Cards
Help Center
1-800-345-4545
Vehicle Info NeededSONNAXPART NUMBER: 852-77987-01K
77987-01K Pinless Forward Accumulator Piston Kit, 4L60-E/4L65-E/4L70-E
$1076
Ships on Sep 04, 2026
Lowest Price Guarantee- Pinless Forward Accumulator Piston Kit
- 4L60-E/4L65-E/4L70-E
- Dual-seal design
Sonnax 77987-01K Features:
In GM 4L60-E, 4L65-E and 4L70-E units it is common for the plastic Forward accumulator piston to wear or crack. This causes a loss of fluid, resulting in delayed engagement, slips, burnt clutches and/or bands. Repeated reciprocation of the accumulator piston causes the piston pin bore to wear, while fluid loss through the piston pin bore or cracks causes Forward clutch to slip. Sonnax pinless Forward accumulator piston kit 77987-01K eliminates these problems.
- Dual seals stabilize and completely seal the bore, providing a tight seal even after thousands of cycles
- Pinless design eliminates the possibility of pin leakage, and the additional length stabilizes the piston to prevent piston cocking
- Includes steel balls for plugging existing pin bore in valve body
- Drop-in Zip Valve parts install quickly and easily
- Piston
- D-Ring
- Seal PTFE
- Steel balls (2)
- Material: Aluminum
Contains:
Specs:
Part TypeAuto Trans Servo Piston
BrandSONNAX
Package Height0.5
Package Width2.0
Package Length2.0
Weight0.095 PG
Part CategoryPerformance Parts
Part FitmentSemi Universal
Package Qty1
Package TypeEA
No Questions
No Reviews
Some parts are not legal for use in California or other states with similar laws / regulations
