Sonnax 35801-02K Shift Shaft & Seal Kit

Leakage from the shift shaft seal is a frequent occurrence in GM TH350 and TH350C transmissions. The main culprit behind this issue is often the presence of scoring on the shift shaft, which hampers the seal's effectiveness. Such scoring and scratches can arise from the intrusion of gritty contaminants beyond a worn seal or from utilizing inappropriate tools during the removal of an old seal. In such scenarios, the seal replacement alone won't suffice, and the shift shaft needs to be replaced as well to restore optimal functionality. However, if the case itself is severely damaged, it is possible to salvage it by installing the provided O-ring into the shaft groove.