Product Details

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Worn bores in the converter bypass line-up reduce TCC control and cooler flow. This results in bushing or planet failure, reduced converter clutch life from overheating and often results in codes 628/1744/1740. Slippage codes are often generated as the unit comes up to operating temperature. As the temperature rises, valve control becomes poor and excessive clearance creates oil leakage. Sonnax now offers a Bypass Clutch Control Kit, 73840-BK, with a tightly toleranced sleeve and plunger valve to restore hydraulic integrity and prevent excessive leakage. Note: This kit cannot address high line pressure in the PR balance circuit, which can break up parts and reduce flow into the converter/cooler circuits. For information on that repair, see part number 73840-RK. The CD4E transmission frequently has concerns of lube failure, harsh shift and line pressure instability. Wear of the pressure regulator (PR) balance circuit (opposite end from spring) creates high line pressure. High line pressure is known to break up parts, but also positions the valve to reduce the flow into converter/cooler circuits. If the vehicle goes into failsafe (no EPC control) the lube circuit can be shut off completely on the OEM design. Sonnax now offers a pressure regulating valve kit, 73840-RK, with a converter regulator valve and PR valve that work together to limit converter pressure, yet ensure flow continues during a failsafe condition. Note: This kit cannot address the loss of valve control at the converter bypass circuit. Wear at the bypass valve contributes to codes 628, 1740 and related converter slip codes. For information on that repair, see part number 73840-BK.