Deterioration of accumulator valve sleeve allows critical throttle, line and/or accumulator pressure loss.
Recover hydraulic control and renew shift operation by installing Sonnax accumulator valve sleeve.
OE valve and spring must be reused with Sonnax sleeve.
Various shift concerns are common in vehicles equipped with GM 4L60-E, 4L65-E or 4L70-E transmissions. This can often be caused by wear at the accumulator valve sleeve. Throttle pressure, line pressure or accumulator pressure may leak past wear pockets in the sleeve, creating harsh/soft or bang shifts. Installing Sonnax DX code accumulator valve sleeve 77754-45 corrects excess wear for revived shift operation and feel.
Vacuum testing at the port(s) indicated fails to hold the recommended minimum in-Hg, or if wear is visually detected.