Transmission Output flange- Needs Parts ASAP
 

Story Time. 1981 W126 OM617 Auto Trans. Driving down the road, just got on the interstate get it up to 70mph and cruise for maybe 30 sec. All of a suddenly my MPH goes to 0 and my engine goes to idle and a slight vibration can be felt on the shifter. I flip on my hazards and pull over to the side of the road, trying to rev it and shift into ANY gear in attempt to make it work. Nothing. Pull over and look, attempting to see anything awry. Well I didn't blow a flex disc, no puddles, nothing dripping. Jack it up with the scary jack and crawl under, the driveshaft has seemingly pulled itself away from the output shaft. Odd. Call up a buddy who comes and hooks a tow strap up and tows me home (2 miles away) Jack it up, take it apart and the actual output shaft is fine, the splines are ok, but the nut that holds on the front flange, has just screwed itself off... WTF

So, since the nut came off, the front flange dropped down onto the output shaft and wore into the flange so the flange and the nut are both unusable..

I need these two parts ASAP.. anybody help?

In Seattle, WA if that means anything...

I got the flange, like new. This happened to me a few years ago. This is a dealers part, costs around $175. Mine is used, but excellent shape. PM if interested.

Thanks,

Some Snappies
 

Here are some pictures

Just wanted to thank Greazzer for getting me outta this jam. Money paid and parts arrived extremely quick. Car went down on a Wed and was again driving me to work Monday morning. Thanks again for your help. Love these forums!

Wow, reading this post is scaring the hell outa me...!

I'm refurbing my driveshaft; flex discs, bearing, mount, boot, etc. Having just removed the shaft this afternoon, I'm noticing a distinct, clear play in the transmission output yoke. By hand, I can move it enough to clearly see this play.

Can also see that this is the source of a slow tranny fluid leak, which I had put down to an old pan gasket.

OK, so what am I in for? Is it possible the retaining nut has simply come loose, as you guys have had happen? Is there a bearing under that nut which warrants replacement at the same time? Probably gotta do the output shaft seal, too...

there is a grease seal (oil seal) under there, the nut needs to be crimped on by tapping the end into the groove.
afik, the nut is the same as the axle nut on W201+ models...

The staked on nut will only be "loose" if the flange to output spline is worn.

In what direction are you seeing free play? Up / Down , rotation when looking at the flange to nut, rotation flange to trans housing when in park, ( this last one is normal )

Duckinator, vstech,

Sorry if I'm slightly threadjacking here, but I'm onto roughly the same job.

Since post above, I've verified that my transmission yoke/nut are not loose. The small amount of play I feel at the yoke is in the output shaft itself. So, how worried should I be? From drawings I've been able to find, it doesn't look like there's an easily-replace-able bearing right under the output shaft seal - can someone verify this? Is a small amount of play considered normal?

I won't be able to replace the trans output seal for the next few weeks at least, so trying to get ducks in a row. My trans uses that dreaded 12-point nut, so have to find that socket - anybody?

Related: In replacing the driveshaft center bearing/bearing bracket, I don't find any circlip - nor even an groove where one might be missing from! Is this AOK on a 126? Other threads here - on 124s, as I recall - show the circlip.

Restating my post 7 above, in what direction do you have free play. The direction matters.

Pfft, the 12point nut is NOT the dreaded one, that's a simple deep 12 point 30mm socket... 6.00 at Sears etc...
The DREADED nut is the one at the beginning of this thread... Them notches need the special socket...

After inspecting the yoke and nut, I should be more specific:

No play at all between yoke and shaft. Yoke not loose; i.e., no worn or wobbly splines. (additionally, nut not loose).

There is the normal play - in the rotational axis - when in park. Not a concern. IE, feels like a few hairs of play in the gears.

However, the shaft will move ever so slightly in any direction - up/down, left/right - in what might be called the car's coronal plane (!)

There is the corresponding wear/slop in the output shaft seal, which has resulted in a slow leak of trans fluid. Does a standard 12-pt socket fit on that damned nut in there (mine is not the slotted one)? Anybody know the size?

Stretch, you've done this work on your 124, I think. Care to weigh in?

Thank you for that - IE, the reassurance that I have the non-dreaded nut on there;). (Do you know if there's any bearing under that seal I can/should replace when I get to this job?)

OK, post 11 is much better. The play you feel is from the ball bearing in the tail shaft as long as the nut is at the proper torque.

Since the nut is staked on, it can be tight against the threads but not place any pressure against the yoke. What happens is the splines and yoke plus end of ball bearing to face of yoke work against each other causing fretting. This loss of material continues until the yokes splines wear out causing it to stop transmitting torque.

The nut might spin once the yokes splines are worn out, but until then the nit will remain staked. A test of this is to tighten the nut and see how far it turns. Sometimes the staking flat on the shaft will allow tightening without unstaking. After you reach proper torque, just restake on a new portion of the nut.

In other words, the splines don't just strip out all of a sudden, they start to wear as time goes on. This kind of wear also happens to rear axle stubs on the wheel side but rarely get to strip out levels. The rust you see is from fretting not water getting in and rusting the surface.

Wow must be the time of the season for this issue....my 78 has been out of commission for probably 4 months now, the transmission started acting up, it would drop gears, not upshift and the speedo was acting wonky....today I crawled under the car, assuming I would need to pull the tail end off....I noticed fluid leaking from the tail end...the more nuts I removed on the flex disc...the more fluid was failing out...finally got the disc off, and the nut was just sitting there....yoke pulled right off....turns out the idiot who rebuilt the trans in 2003 never replaced the nut...or staked it.....so now I am ordering the nut, missing washer and socket to put it all back together....guess this is a common issue...

https://lh4.googleusercontent.com/-Y...903_173041.jpg

hi , does anyone have these parts, to repair output shaft, yoke nut and anything else needed. , or direct me to where they can be found, need my benz back on the road.