You are buying a tool that is used to install the manual shaft seal on any GM late model transmission. It fits, but not limited to:

  • THM 200, 200C, 200-4R
  • THM 350, 350C
  • THM 375B, 400, 3L80, 4L80E, 4L85E
  • THM 700-R4, 4L60, 4L60E, 4L65E, 4L70E

It is very simple to use:

  • Lubricate the installer
  • Simply slide the seal over the tool
  • Insert the small end into the manual shaft hole
  • Gently tap the seal into the counterbore

This tool will hold the seal square to the bore and press on the OD of the seal, thus eliminating leaks and ruined seals.

The manual shaft will have to be removed to use this tool.

We also have the seal sizers available and will combine shipping on multiple orders.