Line pressure from the manual valve is routed through the forward engagement valve in all forward gears prior to applying the forward clutch. Excessive wear at the valve bore or end plug can prevent solenoid feed oil pressure from correctly positioning the engagement valve or allow forward clutch feed pressure to exhaust. This reduced pressure can result in slipping or loss of forward gears, burnt forward clutch or delayed forward engagement. The Sonnax forward engagement valve kit 56947J-56K can restore proper hydraulic function and prevent future wear.
Vacuum testing shows wear/leakage.