I recently put a 545 allison in a mud truck. It was out of a gas school bus, its behind a 454 chevy. My problem is it will not shift past second gear any idea what would be causing this. Any imput will be greatly apperciated. :question:
Check to see if your governor is stuck. It is located under the four bolt cover on the left rear of the transmission. Check the vacuum modulator. If needed there is a low vacuum modulator if your engine has low vacuum.
I have had the governor out and it's free inside, the engine does'nt have a big enough cam to make it have low vacum. But maybe what i am calling low enough is not enough so i will try to find mdulator thanks.