Automatic transmission swap

[fordsmoker55]

I recently purchased a 1991 Thomas built Chevrolet school bus with 34000 actual miles. It has a fuel injected (throttle body) 366 engine with a 5 speed manual transmission and disc brakes front and back. I am thinking about swapping the tranny to an automatic, but I dont really know which one to go for. I have been told to go for an allison mt643 and an at545. I dont really know that much about either tranny, or if I should go with something else totally. Any advice would be greatly appreciated.

 

[frank-id]

swap is good

My opinion is an auto trans does it all better. The Allison trans are a good choice. Care must used to select an auto that is not controlled by a computer.
There are many good trans available for low cost. Frank

 

[Elliot Naess]

Good Dawg.... I'd "kill" for a stick shift in my bus.

Sure, the Allison products are impressively good, but when an automatic fails, it often fails all at once, leaving you stranded. With a stick shift, you can usually make it home. That's a huge difference to my mind.

As for those two Allisons, the MT643 is far preferable, but it would probably come off a diesel engine and would have to be reconfigured to work with the RPM range of your gasoline engine. And there may or may not be such a thing as a bell housing to mate it to your engine.

A Chevy Turbo-Hydramatic 400, built for RV use, might work.

If you must have an automatic, consider swapping in a diesel engine with automatic all in one unit. Big job, though. Reason I'm thinking this, is that your little gasoline engine is probably allready quite worn from pulling such a large vehicle.

Best of luck!

 

[frank-id]

Kill for a stick swap?????

You should make the change as stick trans are usually cheaper to buy than an automatic. In a very short time the parts for the change can be found. Using a hydraulic clutch system will make the change easier. If ya install a 18 speed, you could find yourself in wonderland. The parts are available. If ya really believe that stick is better, make the change. I'm gonna change my Crown from a 10 speed Fuller to a Allison 643. I want my bus to be operated by anyone.
The old guy from Idaho...... Frank

 

[Elliot Naess]

Frank, yes that's my long term plan. If your ten speed is in good condition, I may be interested in buying it from you one day. But I would need to figure out what other parts I need to adapt it to the Cummins 5.9 -- bell housing etc.
Of course, I'm keeping an eye out for a dirt cheap wrecked bus or truck with the whole package -- maybe even an 8.3.

 

[SHORTS]

even with a hydraulic clutch setup, the clutch pedal and mounting are a pita, the actual flywheel,clutch and trans swap is mostly just nuts and bolts, a custom shifter and or linkage might be interesting but the wrecking yard should be full of good cab forward pieces.

 

[Elliot Naess]

I'm pretty comfortable with pure mechanical Stuff like linkages, and I'm thinking I would use a thru-the-floor clutch pedal from a Peterbilt. Ought to be much easier than installing a hanging pedal where none was expected.

 

[the_experience03]

All American's were offered with a manual transmission for a time. I don't know what kind of parts availability exists or if they transplant well into a TC2K, but it's something to look at, Elliot.