June 06, 2018
All Over the Map: Attacking 4L60/E Burnt 3-4 Clutches with Confidence
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.
Sonnax valve body layouts provide a detailed overview of individual units making it quick and easy to determine what’s available for the specific valve body you’re working on. See all Sonnax valve body layouts.