Chaffee Transmission Questions

[Malcolm Towrie]

To anyone with a Chaffee tank who finds this thread, the NOS G749 Hydramatic seal and gasket kit is useful because it has the round gaskets and v-cup seals necessary to seal the cooler in the pan (but see below). However, the pan and side cover gaskets don't fit. And the clutch apply piston rubber seals are the old style that need the brass expander so they still seal when they get hard and brittle after a few years. Modern Hydramatic kits have piston seals that don't require the expander.

The v cup seals for the cooler have the number AN6225-25 on them which is still available. Buy the 90 durometer ones in Buna N (nitrile).

The round gaskets can be made with 1/16" material.

Pressure test the cooler compartment to a few psi with air. The cover on mine was warped and leaked until I used RTV on the gasket. Dribble water into the two interspace drains and look for air bubbles.

Dribble water into the interspace drains and apply a couple of psi with a rubber -tipped blow gun to confirm the v-cups seal.
Beats finding the leaks when it's all installed in the tank.

Malcolm