How to remove MT643 from an '85 FC

[maustin]

That post #32 of "the tranny in the bus......" sure looks like the ticket for removal of the tranny. After looking at the situation up close, I'm thinking that I can support the tranny on a tranny jack (in front of the axle) with a steel plate on top of it that also rests on and overhangs the axle. I'll slide the tranny back the 10 or so inches available, and remove the torque converter. I'll then change the seal and reinstall the tranny.

Since I don't really need to have the transmission out from under the bus, I hope to avoid the extra work of dropping the axle. (I will be on my back through this little project).

Wish me luck, I'll post pictures and complications here for the next one up against this.

Mike

[Randy Dupree]

I think you can do it that way.
good luck,be careful!

[fxdwg]

Just amke sure you get that converter seated in the front pump before you go pushing the tranny back up again. It's sure easy to bust a front pump housing with a not fully seated converter.

[oldbird]

be very careful when you pull the tranny. the flex plate can be bent easily. if it is it may not be useable and expensive to replace.

[warbucks13477]

I have read all of the posts on removal of the MT-643 allison transmission in a FC and I had my local shop pull the transmission to replace the rear main seal in the engine. They did not remove the airbags or axel however they did proceed much as Mike Hohnstein noted. They had never done it before and I had just got out of the hospital so could not physically help them however I did sit beside the coach and explained how to do it. The hardest part for them was to remove the top transmission bolt. They needed a very long socket extension just to reach it but they quickly got all of the bolts out. Strapped the tranny to a transmission jack and separated the tranny from the engine.
They had previously elevated the front of the coach using two OTC 1520 wheel lifts and then supporting the chassis using high jack stands. Then they slowly lowered the wheel lifts until the axel was even with the bottom of the tranny.

They then placed another transmission jack behind the axel and moved the front jack and tranny back against the front of the axel and slid the tranny over the axel unto the rear tranny jack and pulled the tranny out. Replace the seal and then reversed the process. They did not have to remove the airbags or axel.