Input Shaft Seal Ring Expander and Installer Tool for GM 6L80 6L90E Transmissions

The Teflon (scarf-cut) sealing rings on the input and turbine shaft of a GM 6L80 or 6L90E are one of the easiest places to ruin a rebuild. Slide a fresh ring on cold and you nick it, roll it, or stretch it past its shape, and now you have a leak path that shows up as a slipping or overheating transmission the first time it sees line pressure. This tool takes the guesswork out of it.

You use the expander to gently open the new ring so it walks over the shaft and into its groove without being cut or forced, then the re-sizer collar closes the ring back down to the correct diameter so it seats square in the bore. That two-step expand-then-size process is exactly how these rings are meant to be installed, and doing it by hand is how most people end up with a comeback. The tool holds the ring concentric the whole time so it goes on relaxed and sizes tight.

Machined from steel with a corrosion-resistant finish so it survives a working bench and repeated rebuilds. If you are doing 6L80 or 6L90E units, whether it is a truck, SUV, or a Gen-V V8 swap, this is one of those small tools that pays for itself the first time it saves you from tearing back into a fresh assembly. Ships from the USA.