In Ford 4F20E and Jatco/Nissan RE4F02E transmissions, the accumulator shift valve lineup has been changed numerous times by OE and incorrect reassembly can result in soft or flared upshifts. Sonnax accumulator shift valve kit 63940-03K includes an accumulator shift valve that will be correctly positioned to prevent soft or flared upshifts.
Replaces early or late OE lineups in most valve bodies. Some late valve bodies do not have an accumulator shift valve.