Tool Required VB-FIX Required
- Burnt converter
- TCC apply & release concerns
- TCC codes
Bore wear and/or broken sleeves create an unstable or mis-positioned valve. Mid-stroke will cut off cooler flow and overheat the converter. Bore wear at the signal end creates a cycling action of the valve, resulting in TCC slip or RPM cycle with the valve.
The Sonnax oversized lockup control valve and cutback valve kit restores TCC apply and release pressure control and corrects valve positioning. This kit works with modulated TCC apply systems only
Oversized Lockup Control Valve & Cutback Valve Kit
- Lockup Plunger Sleeve
- Lockup Plunger Valve
- Lockup Control Valve
- Cutback Valve
- Oversized Cutback Sleeve
- Cutback Spring
This kit fits '98-later models: Isuzu NPR, GMC Forward Tiltmaster, Chevrolet Forward, Nissan UD and Mitsubishi Fuso Trucks.
Vehicles with Aisin AW 450-43LE transmission may exhibit TCC apply and release problems, burnt converters and damage and loss of TCC friction lining. Wear is commonly found at different areas in the lockup control valve bore. Wear at the lockup control valve bore prevents the valve from stroking to the lockup position. Wear at the lockup plunger sleeve causes lower TCC apply and release pressures. Sonnax oversized lockup control valve and cutback valve kit 94987-05K restores hydraulic integrity to properly control the apply and release of the torque converter. The material for the valves has been upgraded from OE steel to hard-coat anodized aluminum. The precision sleeves are manufactured from highly wear resistant aluminum.
- Valves are hardcoat anodized to reduce wear
- Sleeves are manufactured from highly wear-resistant aluminum
Required tool kit F-94987-TL5 is no longer in production. Check with your distributor for availability.
This kit can only be used with modulated TCC apply systems.