Can i ask, how long have mercedes used ATF for manual gearboxes ? .I know a few makers used it in the past .

Sorry you do need atf you learn more every day

See post #5 above.

There is, or should be, a nut hidden in the dirt and grease inside the yoke. That nut screws onto the mainshaft/output shaft to retain the yoke.
As noted in post #5, the shaft splines are harder than the yoke, and may have survived.

There's a big staked nut holding it on. It's like the end of a contemporary CV joint.

Should it have been visible in the photograph I took, on the rearward side of the yoke? Because all I removed was the flex disc, nothing else, and that’s how it looked. It’s a ‘79 car; perhaps later models have the nut? Thanks to all for responses!

I’d really like to get the yoke off, which would uncover the splines and reveal whether the shaft splines are ok.

In early cars, the nut isn’t a 6-point hex but an annulus with 4 recesses. In ATs the annulus can be replaced with a more conventional nut.

http://www.peachparts.com/shopforum/...ecial-tool.jpg

I found a deep socket that matched the outer diameter of the nut, ground the open end into prongs that fit the recesses, then blasted off the nut with an impact wrench.

Sixto
98 E320s sedan and wagon

Dang, I think I have the annulus style.

An older Mercedes mechanic may loan you the tool. Of course offer to leave a reasonable deposit. It does sound in general that the splines will be usable again. Or at least the odds they are might be in your favor.

Hunters description of the second gear grinding that is really not that uncommon on the 240ds. Plus his information in an attempt to rectify it should be helpful to many. Neither of ours grinds into second gear though.

They are 1979 and a 1983 versions. Rust unfortunately has gotten the upper hand on the relatively low milage 1983 24Od. I will still retain it as a parts car for the 1979.

Fortunately these old transmission are still not that hard or expensive to find if the need is there either. I even have one in a 1972 gas coupe.

Good luck with the repair .

Thanks, optimusprime. Sixto has generously agreed to send me his tool, so once that arrives I'll have a go at getting the fastener off. In the meantime, I need to grind off the staked portion of the fastener. I noticed from Sixto's photo that it appears that he was able to block the yoke from rotating while loosening the fastener - since my yoke is stripped I think I will have to put the car in 4th gear and put a breaker bar on the front of the crankshaft , similar to what I do when turning the engine while adjusting the valves. Does anyone see any problem with that?

I know that with these diesels the engine should only ever turn clockwise, never counter-clockwise. I verified yesterday that when the car is in a forward gear, the sense of rotation is preserved as the motion is transmitted through the transmission - that is, when the rear wheels turn as though the car is moving forward, the transmission output shaft turns counter-clockwise when viewed from the rear. CCW from the rear is the same as CW from the front, hence preserved. All of this is a long-winded way of saying that when loosening that fastener (CCW) I'll be trying to turn the engine in the natural clockwise (viewed from front) direction, so low risk. When tightening the nut I can block the yoke and leave the car out of gear, so no risk there, either.

Chime in if you see any flaws in my reasoning... thanks, guys.

Kurt

That’s not my picture, just one I found on the site. It might be our good friend stretch. I used an impact wrench which doesn’t need much resistance. The safest bet is to use a ring gear lock. There’s one that holds the ring gear at the very bottom and one that fits in place of the starter. I suppose you can hold the crank pulley bolt but lash down the stop lever since CCW at the yoke is CW at the crank; i.e., the engine might start. Also, mind that you don’t loosen the crank pulley bolt in the process.

Don’t 615/6/7 engines have a keyway so you can lock the crank damper against the front cover?

http://www.samstagsales.com/mercedes/bu601-0240.jpg

Sixto
98 E320s sedan and wagon

Nice bit of kit that one .

BMW still uses ATF in manual gearboxes. The only reason to use heavier gear oil is when its combined with the diff as an integrated transaxle.

Some BMW enthusiasts do a 50/50 mix of ATF and 75w90 gear oil, just for added wear protection when doing autocross or track events, but the viscosity can make the first few cold shifts in the winter kind of difficult.

Update: nut and yoke removed
 

OK, so with Sixto's tool I was able to remove the annular nut holding the yoke on. As I expected, the softer yoke is completely stripped - see photo. The transmission shaft doesn't look too good either, to be frank. I'll post a couple of photos here, for comment by anyone with experience.

By the way, I didn't go to the trouble of blocking the flywheel. I just put it in first gear, figuring that the torque I put on the nut was going to get divided down going through the transmission. The engine didn't even budge when I broke the nut loose carefully.

Anybody got a good yoke they want to sell? Or even one to loan just to put on the shaft and see how much play there would be in the current state? Opinions on brands of rubber for a new flex disk?

Thanks, as always.

Kurt

Sorry to say, the shaft splines are toast.