Staghound Hydramatic Transmission Question

[Malcolm Towrie]

Rob, great info on the Honeywell switches. Just what i needed.

Regarding the two pressure taps on the one Hydramatic, I suspect the one you are seeing that's close to the engine, ie not between the two band adjustment screws, is not a pressure tap at all but the 1/8" NPT cover on an indicating pin that allows adjustment of the front band without removing the side or bottom pans. Check down the hole with a mirror. If you see the top of a 1/8" pin, that's what's it is. This is not a source of tranny pressure, so having a switch on there does nothing.

On the Chaffee, there is another pressure tap on the transfer case side of the two adjusting screws. I think it is unique to the Chaffee. It's an intake manifold vacuum source to the tranny, used as a source of engine load for modifying shift points. I think the M5 uses a linkage to the valve body from the carb throttle plate, same as the Staghound does.

Malcolm