How to remove MT643 from an '85 FC

[maustin]

I've had nothing but good luck here on the site. Now I have the front seal leaking on my 85 FC. I've read most of "Tranny in the bus goes.....", but what I'm needing now is input from someone that has removed the tranny. I do not have a pit, but do have all the tools, stands, and tranny jack. How is the best way to deal with the fact that the tranny straddles the front axle?

I'd also be interested in purchasing a factory service manual for the chassis if such a thing is out there. If it is, I've yet to find it.

Other than this issue, all is well with the recent 'Bird purchase, just got back from four days of boondocking it while trout fising.

Thanks,
Mike

[Randy Dupree]

first things first!
before removing the tranny,make sure its the front seal,and not fluid running down from above somewhere!

[sanibel]

Cannot help with pulling it. I did not get a "Chassis Manual" in my BlueBox. I think there is not one as everything is componentized. The truck or coach builder starts with the chassis, then specs out what brakes, axles, suspension, engine/trans, etc. to make it all work. I got all the component manuals, but they do not cover how it all comes apart. My money is on Randy having the answer. He seems about as close to a manual as you can get.

[maustin]

The fluid is coming from inside of a small inspection plate on the bottom of the bell housing. It is not slung radially from the torque converter, it comes from the rear as you look in the cover. Unfortunately the clearences are such that an inspection mirror cannot be inserted. So, I'm thinking the front seal or a gasket on the front of the pump.

I agree that the chassis is a collection of components, but I did find a chassis manual for an '02 Bluebird. I would like to think that a manual was printed to direct mechanics on proper assembly/disassembly procedures. But, who really knows.

Thanks,
Mike

[Turbokitty]

Is the leaking fluid red or brown? I guess you said a front seal which is the front of the trans. (red oil) I had our trans. completely rebuilt just after purchasing the coach. It was done as a precautionary measure. My transmission was rebuilt by Heller Transmissions in Clearwater, Florida. They are a certified Allison repair facility and a first class shop, clean is an understatement! Anyway, when they got mine apart the found the front pump housing cracked and replaced it. I guess what I am saying is do a thorough inspection when you get it out. Lastly, getting the trans out of my 83 bird was a @#$% for them. It can be done but the front axle is a bottleneck. Good luck and be careful.

[Randy Dupree]

Mike,it sure sounds like a pump seal or pump gasket.
I do believe that the tranny can come out without removing the axle.
It would take a heavy duty tranny jack for sure,like a 5000lb cap. jack.
I think a jack like that could rech up and over the axle to support the tranny.
and extension on the jacks table may be required,3/4 plywood may do it.

[maustin]

Its transmission fluid.

Yeah Randy, It looks like a real tight job to pull off. I read about someone here talking to their local school bus shop. I think I'll give that a try as our small town district has an older Bluebird fleet. If I get any useful info, I'll post it here for the next guy looking to seal a tranny in his driveway!

Thanks guys,
Mike

[gcyeaw]

Mike,
If you figure it out, PLEASE take pictures and write up an explanation of how you did it. Next time someone is on the road with a tranny problem it will be worth its weight in diamonds. Believe me, I know.

[fishfarm]

The 600 Series Mechanic's Tips might help. Section II is "Removing the Transmission."

http://www.allisontransmission.com/s...t=MT1357EN.pdf

[iamflagman]

Mike Hohnstein outlined the proceedure needed to change the transmission in post #32 of;
Wanderlodge Owners Group > Mechanic's Corner > Transmission > The tranny in the bus goes bump-bump-bump

Originally Posted by Mike Hohnstein

The chassis needs to be elevated about 36" to bottom of frame to floor. Disconnect air bags and shocks. Drop axle down, control arms will stabalize axle. Drain trans disconnect transmission lines, and place ends in a bucket, they will drain creating a mess. Disconnect drive shaft, shifter cable and TV module. Remove torque converter nuts and coax converter toward transmission so it wont bind on flywheel when removing trans. Remove Using a truck transmission jack at least one ton capacity and taking care to strap trans to jack base, remove transmission being careful not to drop torque converter. It will fall out if trans tilts forward. A steel strap bolted to bell housing after trans is moved back from engine, before lowering process is a wise move.
A through flush of the radiator heat exchanger and any external coolers that may be part of the mix is mandatory for successful reinstallation.
It is not a simple or easy process but a competent truck shop should be able to do the job with minimal complications. I know a shop that could do a good job but they are in the Pittsburg area.
MH

He followed up with a note about the panhard rod also needs to be removed.