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.