Re: 55 ultramatic problem

Posted by Ross On 2010/6/28 22:10:06

I go with the stuck governor: The governors rely on the rear pump for pressure to send to the valve body. That is why you get up to 5 mph before it shifts; before that, there is no significant rear pump pressure. When coming to a halt, it takes a while for the rear pump pressure to dissipate, and by then the direct clutch has stalled the engine.

As mentioned, cleaning the governors is no hard task on your car. You might want to double check that the spool in the high-speed governor is not in backwards.

While you are in there, I would also remove the rear upper valve body, which has the direct shift valve in it, and make sure all is well and correctly assembled. This can also be removed without removing the whole valve body with a little imagination and fiddling.

Please let us know what you find. Inquiring minds want to know.