Broken rear coupling - 1988 230TE

[balge59]

http://forums.mercedesclub.org.uk/album.php?albumid=165&pictureid=1110

Well the story is - reversing up hill in a tiny carpark (due to some numptys' bimmer parked like a 3 year olds tricycle...), big bang, no more go - looks under the car to see the above mess. Also picked up a snapped bolt and two large steel/rubber 'washers' -unfortunately lost now
Further examination at home shows the flexible coupling disintegrated and apparently not much other damage - CV boot (?) ripped on the passenger side, ABS sensor cable, few bangs and knocks.

What I'm wondering is - will it be worth just replacing the flex coupling and boots or is there any other problems likely - as it happened at below walking speed will it have bent the propshaft or something? What should I be checking?

Also, what does the bolt screw into, will there be a problem if it needs drilling out or such? I think the 'washers' are spacers off the broken bolt, which is supposed to hold the diff up, right? Cant find an assembly drawing for it yet...

cheers!

 

[teddycatkin]

Should be fine ---just get a replacement kit (incudes bolts) Euro C/P or you may find one on fleabay?
Goodluck with it Teddy!

 

[television]

It could pay you to get a secondhand prop all complete

 

[kth286]

I cannot see your picture.

 

[balge59]

Think the bottom one is mine? That's two pieces, if the bearing in the middle there feels ok I think I'll go for trying the old one first

Diagram part number 179 is the rear I think? EPC gives it part number
A 202 410 13 15?
Had a look at EuroC/P but got a bit confused -

http://www.eurocarparts.com/ecp/c/Mercedes+Benz_200+Series_230_2.3_1988/p/Car-Parts/Transmission/Transmission-Parts/Propshafts-and-Components

no plain ole 'rear', - do I need the front/rear, the other front/rear or the rear/rear/front lol? I'm guessing its the £38 one or the Lemforder at £56 or are they all different?

cheers

oops sorry messed the picture - linked to gallery now!

 

[teddycatkin]

Lemforder = original part !

 

[balge59]

Aha - hmm well as I was in two minds about breaking the car I may have to go with the cheap option, should still see the rest of the car out lol

Lets try the pic again -

cheers!

 

[Number_Cruncher]

The propshaft joint has failed because the front mounting for the diff has failed. I imagine that the rear mounting for the diff will also be damaged - if not fully seperated.

It will also be worth chiecking very carefully in the area where the prop shaft and diff slide together - this joint is what keeps the shaft running central, and the broken rubber part just transmits the torque.

 

[television]

I would still get a secondhand prop from Rob parker

 

[balge59]

pictures - can't seem to attach anything properly so here's a link to Picasa album -
http://picasaweb.google.co.uk/balge59/1988230TETransmission#

see if that works.
The three legged spider thing is still attached to the diff, just pulled the rubber off I think - didn't try moving it yet though...

I hadn't thought to check the front end yet - assumed the flex thing broke because the mounting bolt snapped and it pushed the diff down too far?
Will get back under ASAP and check the front mountings

cheers!

 

[balge59]

The propshaft joint has failed because the front mounting for the diff has failed. I imagine that the rear mounting for the diff will also be damaged - if not fully seperated. .

ahh - I thought it was on two studs at the side and it had just spun on them? you mean there's one at the back?


http://picasaweb.google.co.uk/balge59/1988230TETransmission#5488912753808129218

in the middle, just down from top

EPC only seems to show one bolt (N000912010238) with two washers to mount to the subframe is there another one somewhere else?

cheers!

 

[kth286]

that is a most unusual situation you have there.

is the car new to you ?

The diff is held in place within the subframe by 3 bolts.

Two at the rear of the diff, which is held in place and fixed to rear of rear subframe via two renewable bushes which do wear.

One bolt at front side of diff fixed to subframe.

The diff centralising bush for propshaft may have now got bent, so be aware.

It may be that the drive shafts inner joints may have been destroyed, so be aware of that also.

The subframe itself may have been damaged at bolt/bush fixings, so investigate.

It maybe the rear subframe is rusty and gave way at those stress points.

 

[balge59]

hi
Had the car 4 or 5 years now...(7 actually...)

Are the 2 bolts at the back vertical or horizontal?

There was a snapped bolt and two spacers lying under the car when I got out and looked under it - must have been the front mounting bolt? Is that bolt going to be reachable without dropping the subframe, at all?

"The diff centralising bush for propshaft may have now got bent" - you mean there's a bush in the front of the diff, or the one halfway down the prop? - yea, will be checking that, once I work out how...

Only just worked out the diff was fixed to the subframe lol

 

[kth286]

the centralising spigot is visible on the end of the diff lying against ground with the 3 outer flexible coupling bolts.

That diff is very heavy.

The two rear mounting bolt threaded holes are at each side of the diff.

 

[balge59]

"The centralising spigot is visible on the end of the diff lying against ground with the 3 outer flexible coupling bolts"

So that would be 'centring bush rear' part no. A1244100732, fits over the projection in the middle of the flange coming from the diff, right? k got it, something else to check!


Oh, one more question - "It may be that the drive shafts inner joints may have been destroyed, so be aware of that also." - you mean the actual driveshafts bearings? that's the CV? K, will try and check them too

cheers!!

 

[Number_Cruncher]

ahh - I thought it was on two studs at the side and it had just spun on them? you mean there's one at the back?


http://picasaweb.google.co.uk/balge59/1988230TETransmission#5488912753808129218

in the middle, just down from top

EPC only seems to show one bolt (N000912010238) with two washers to mount to the subframe is there another one somewhere else?

cheers!

http://www.auto-parts.spb.ru/cat/cats/m.mycat?Form

There's one mounting at the front - bolt 23 and the washers and rubber washers you've found.

There are also two mountings, 8, at the rear of the diff, with bolts, 11.

As per kth286#s posts, there's likely to be more damage - the spigot, the subframe, etc.

That's a difficult failure to deal with - you can't even tow the car away as it stands. So, checking and sorting out the diff mountings in my W124 has just moved up the "to do" list.

 

[balge59]

sorry links not working for me - getting '400-bad request'...

aye, had to get the recovery to put an oilpan under the bits to 'skateboard' them along...not fun

Anyone know if the washers and stuff are designed to provide any stated clearance/gap whatever? Length/size of the bolt?

I think it was 'just' the bolt itself snapping, 23 years old and under extreme load - but I need to get under again and check the subframe for sure!

cheers!

 

[balge59]

hi
so, had another go at this, think I understand it better now.

Front flex-disk and centre bearing both seem to be alright, the centralising spigot seems to fine as far as I can tell without spinning it, so I'll go with that for now. The drive flange seems to be turning smoothly, so the diff ought to be ok. Small amount of free-play at the gearbox end of the drive, very small amount, probably normal...

1 As to the mountings can anyone confirm the assembly order for the front bolt? The drawing is a little confusing, I'm thinking - rubber faces of the washers (32) touching the frame bracket from underneath and above, sandwiching the bracket, steel spacer washer (26) below the lower one, nut (35) above the bracket?

2 Is that spacer (26) specific to chassis or is it to set something? EPC lists from 1 - 4mm, and something about 'identification rib' or 'stamped on characteristic of 8mm'

3 Other thing is the rear mountings, are the rubber things (8) bolted to the diff case and then just pushed into the holes in the subframe, simple as?

4 How do I check the drive-shafts, what am I looking for, backlash, roughness, that sort of thing?

Any light on any of these welcome!

 

[teddycatkin]

Your assembly idea seems correct-follow diagram--as for bending it takes a lot to damage or bend anything the doughnut has given and caused the bang--if you were going in reverse then the diff will have dragged along the floor and should not be damaged or stressed the drive shafts !
Good luck.

 

[balge59]

If the diagram made sense I would follow it lol. Have to make do with common sense I guess...
Oh my, yes if the diff went up rather than down, that WOULD have been messy! Good job I was barely moving...

cheers!