Technical Bulletin # TCB4
Transmission: 4 & 5 Speed Transmissions
Subject: No Lockup After Rebuild
Issue Date: October 2010
No Lockup After Rebuild
A no lockup condition after rebuild, setting torque converter performance codes on some models. The type of transmissions that are affected are models with a Lockup Control Valve and Sleeve in the valve train (figure 1). The problem is caused by installing the Valve Cap incorrectly into the valve bore (figure 2). The notch cut out allows oil to enter the sleeve to stroke the Lockup Control Valve. When installed backwards; will restrict the flow of oil through the Valve Sleeve to stroke the Lockup Control Valve. This can also occur with an Aftermarket Valve Cap without a notch cutout.
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