The OE design of the control valve allows for smooth apply and control of exhaust release oil. However, if there is any converter or cooler restriction, converter feed is reduced. This allows the valve to stroke prior to lockup command, resulting in premature TCC apply. This can be aggravated by wear at the plunger valve sleeve due to continuous oscillation, allowing the oil pressure needed to hold the control valve in the release position to exhaust instead. The Sonnax assembly includes a redesigned plunger valve assembly and control valve to prevent premature TCC apply. The new control valve has eliminated the controlled release exhaust reaction spool, which often has a worn bore that causes lockup complaints. The plunger valve sleeve has been extended to aid in sealing this circuit. An orifice plug is included to block the controlled release circuit. These changes prevent the control valve from stroking prior to lockup command due to any converter or cooler restrictions, and are designed to result in a short and firmer TCC apply than OE.
This kit also services Jatco FP series; Ford JF506E, FPH; Jaguar JF506E, FPD; Mazda JA5A-ELFPF1/FPF2; Rover JF506E, FPO; and Nissan ZY units.
Contact a Sonnax Parts Distributor.