Is the trans output shaft removable while still in car

[stangsteve]

Driving to work on the freeway in my 83 300sd I heard this loud grinding noise coming from the trans. I made it to the side of the road, 1/4 miles before the baybridge toll plaza. The trans had no forward or reverse. Caltrans was nice enough to tow it to the shop where I work as a mechanic. What I found was the nut that holds the flange to the output shaft of the trans came off. This caused the flange to disconnect from the out output shaft at 70 mph. The splines of the flange got ground away by the spinning output shaft. No big deal to change the flange, I have a spare. The problem is the the threads of the output shaft are pretty cewed up too. Is it possible to replace the output shaft on the trans with the trans still in car thanks Steve

[wbain5280]

I've never done it but I do know that the back section of the trans will unbolt and can be removed. After that, I don't know.

You're lucky the flex disc didn't disintegrate. That would have really screwed things up.

[wbain5280]

This might help:

http://www.peachparts.com/shopforum/vbpicgallery.php?do=view&g=847

[C32AMG]

The transmission must be totally disassembled, output shaft is part of the rear planetary.

[t walgamuth]

i would take a very careful look at the threads. perhaps you can clean them up and reuse them without tearing the tranny down.

i would get a die or tap and clean them carefully.

tom w

[Ken300D]

If the threads are completely toasted, would it make any sense to weld the stupid flange on?

I'm calling it the "stupid" flange because I think mine is loose. It hasn't stripped the splines but I think it is loose enough to wobble. I have the car (82 300D) parked until I can get it checked out more closely.

Ken300D

[stangsteve]

Thanks guys, does anyone know what size the output shaft threads are. I was thing about cleaning up the threads then try to get the nut on & tack weld the nut. The only problem is a chance of damaging the rear seal

[Johnt49]

Does this look familiar?
http://www.peachparts.com/shopforum/showthread.php?t=158193

I bought mine with the same problem. PO thought trans was shot, so I got it cheap. I would try to thread on a new nut. Don't try to reuse the old one. They're only good one time. That's probably what caused it to come off. Someone probably reused it already. There's a recess machined into the shaft at the back edge of the threads that you peen the outer edge of the nut into to lock it in place. If you get a new nut, get the one with 12 points made by Febi, rather than the OE groove nut. It's much easier to work with and doesn't require the special groove nut socket which is expensive. The output shaft is hardened & will be hard to chase with a die, plus you risk breaking the threads off, not to mention the price of the die. The nut will thread on even if not smoothly. You may have to turn it on & off 1/4 turn at a time like you were cutting threads with a die. It should be torqued to 75 ft lbs & the nut peened into the recess to lock it in place. I'd also change the seals while it's apart. Here's the part numbers you'll need:

nut: 123 990 00 60
Tailshaft housing to flange seal: 012 997 87 47
flange to output shaft seal: 018 997 19 48 (this one may be hard to find and a small bead of silicone sealer can be used if necessary)

I've got a pdf showing the parts, but it's too big to post here. If you want it PM me with your email address & I'l sent it to you.

[t walgamuth]

excellent description, john.

tom w