W126 drive shaft carrier/center bearing DIY - PeachParts Mercedes-Benz Forum

whunter · #1 06-09-2010, 03:18 AM

W126 drive shaft carrier/center bearing.

MARK THE DRIVE SHAFT FOR RE-ASSEMBLY, BEFORE SEPARATING THE SLIP JOINT...
The rubber carrier boot can be replaced without disturbing the bearing.

#1. Mark the alignment/orientation of the drive shaft assembly before separation !!!
WARNING: Scratch a mark that can NOT be wiped away, then you can use a paint pen to enhance it.
#2. Loosen the slip joint nut.
#3. Separate the slip joint.
#4. Set aside the Rear section of the drive shaft.
#5. Mount the Front section of the drive shaft in a vise.
#6. Remove and clean the slip joint nut.
#7. Install the new slip joint nut boot.
#8. Clean and lubricate the internal slip joint splines with axle grease.
#9. Set aside the Front section of the drive shaft.
#5. Mount the Rear section of the drive shaft in a vise.
#6A Type one: Remove the snap ring.
#6B Type two: This type of pressed on debris cap has an internal lip on the outer face, and must be removed to access the carrier/center bearing snap ring = pry off cap and remove the snap ring.
#7. Press or knock the bad bearing off the drive shaft.
#8. Remove the rear debris cap.
#9. Install the new rear debris cap.
#10. Press or carefully hammer the new bearing on to the drive shaft, (drive only on the edge of the inner bearing race).
#11A Type one: Install new front debris cap and snap ring.
#11B Type two: Install the snap ring, then pressed on the new debris cap.
#12. Instal the new rubber carrier boot.
#13. Install the slip joint nut with new boot on the spline shaft.
#14. Verify the internal and external slip joint splines have been cleaned and lubricated with axle grease.
#15. Pick up the Front section of the drive shaft.
#16. Re-assemble front and rear sections by matching the alignment/orientation marks of the drive shaft assembly.
#17. Hand tighten the slip joint nut, (final tightening MUST be with the drive shaft mounted in the vehicle).

Here is a related DIY LINK.

Driveshaft, Axle & Wheel bearing
Driveshaft, Axle & Wheel bearing

cghncn

Stretch · #2 06-09-2010, 04:02 AM

I've just done my W123 shaft. When marking the two halves of the shaft I found it useful to mark not only the outer surface of the shaft but I also marked the spline next to the nearest slot... see photograph!

Over kill I know. But it might help another nervous one...

atomix8 · #3 06-09-2010, 08:02 AM

In case anyone needs motivation...the local, somewhat expensive indie quoted me $440 to do the carrier on my w123...

This is starting to look DIY-able.

jride100 · #4 06-09-2010, 07:49 PM

I removed my transmission and the forward half of the drive shaft without marking the two halves. Why exactly is it needed to get them back together in the previous alignment? I assume it is a balance issue. Any way of determining the correct orientation now that it's apart?

69shovlhed · #5 06-09-2010, 11:22 PM

yes its a balance issue. if your lucky there may be some sign of where it went. otherwise its trial and error.

whunter · #6 01-15-2014, 07:17 PM

Recycled for new members

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vstech · #7 01-16-2014, 12:10 AM

HOW did you get so many pictures on the single post? I thought 5 was the limit????

whunter · #8 01-16-2014, 01:23 AM

Quote:

Originally Posted by vstech

HOW did you get so many pictures on the single post? I thought 5 was the limit????

Many posts, then use moderator power to merge them all.

.

vstech · #9 01-16-2014, 01:45 AM

That's what I was thinking...

so, still have to make a lot of posts to get the pics in there.
oh well...

benhogan · #10 01-16-2014, 01:39 PM

does this procedure apply to the w201 190d as well?

whunter · #11 01-16-2014, 07:20 PM

Quote:

Originally Posted by benhogan

does this procedure apply to the w201 190d as well?

The few variations are IMO minor.

.

musikpal · #12 05-24-2014, 08:40 PM

I was trying to free the front half of the shaft from the front flex disc with a pry bar and,without brain ,I grapped the rear half and pulled on it. The rear half just came off(so easily). So my question is; Is the big nut that surround the slot where the spline goes in supposed to lock the spline in place? In another word, Should the spline came off easily like that? Im guessing that the slot is flexible n can b tightened n opened by the big nut. And for the marking, the relation of the nut to the front shaft are what being marked here, is that correct?
By the way Im working on w116.
Thank you guys

Stretch · #13 05-27-2014, 01:50 AM

Quote:

Originally Posted by musikpal

I was trying to free the front half of the shaft from the front flex disc with a pry bar and,without brain ,I grapped the rear half and pulled on it. The rear half just came off(so easily). So my question is; Is the big nut that surround the slot where the spline goes in supposed to lock the spline in place? In another word, Should the spline came off easily like that? Im guessing that the slot is flexible n can b tightened n opened by the big nut. And for the marking, the relation of the nut to the front shaft are what being marked here, is that correct?
By the way Im working on w116.
Thank you guys

The nut is indeed intended to lock the spline in place on this design. Locking this nut (and other parts) after the vehicle has been rolled forwards and backwards is a trick people use to "cure" vibration problems...

The markings should be made from shaft to shaft not on the nut. If you are getting really anal mark from spline to spline! But it sounds like it is a bit late for that.

I've never worked on a W116 before so I can't really say for sure if this could happen but on my W123 and my W201 (similar set up) there is no way on earth the rear shaft would just fall out.

Have you removed the differential?

Are your subframe bushings and motor mounts totally and utterly knackered?

musikpal · #14 05-27-2014, 03:58 PM

Thank you Tristan. Yes the axles n differential were removed long time ago. I was changing my axles from one piece type to two pieces type(anular??) so it took me awhile to figure out what would fit.

Anyway, looking at the last 2 pics from whunter's post, I can see that the female part on the end of the front shaft has 3 cuts and the big nut is used to close these 3 gaps. When the gaps are not closed that's when we get vibration. And that's why we mark the location of the turning of the nut. Is that wrong??? Other than that I can't see the reason since everything is symeyrical.

Stretch · #15 05-27-2014, 05:19 PM

Quote:

Originally Posted by musikpal

... Yes the axles n differential were removed long time ago. I was changing my axles from one piece type to two pieces type(anular??) so it took me awhile to figure out what would fit.

...

That explains why the back end fell out - I guess you left it hanging there for quite a while!

Quote:

Originally Posted by musikpal

...
Anyway, looking at the last 2 pics from whunter's post, I can see that the female part on the end of the front shaft has 3 cuts and the big nut is used to close these 3 gaps. When the gaps are not closed that's when we get vibration. And that's why we mark the location of the turning of the nut. Is that wrong??? Other than that I can't see the reason since everything is symeyrical.

No it isn't like that at all.

Firstly if you look on the propshaft halves you will see that little weights have been tack welded onto the shafts at different positions - if you do not align the shafts correctly they will be out of balance.

This is why later propshafts were marked at the factory.

^^^^ That's the first point I'll make.

Vibration can be a result of many things but one thing that can happen is as follows...

(Get ready for a long explanation! I'm tired and probably won't get to the point that quickly...)

The engine is mounted on two rubber mounts.

The gearbox / transmission is mounted on rubber mounts.

The subframe and the back of the differential are also on rubber mounts.

The propshaft is of a fixed length once the big nut is tight (or it should be) but it is also in the middle on a rubber mount in front of the SINGLE universal joint.

If by bad luck / bad positioning the propshaft is fitted between the differential and transmission + engine and it is tightened in a position that is too long or too short the propshaft is not in a straight line.

With a SINGLE universal joint (UJ) this might mean that vibrations are induced by spinning - a double phased UJ set up counteracts UJ vibrations - a single does not.

(see Universal joint - Wikipedia, the free encyclopedia)

So the trick to make sure that everything has settled in the best place is to put the car on its wheels and then roll it backwards and forwards before tightening the big nut. In this way the parts are in a preferential position that will hopefully not cause any UJ induced vibrations. It also means that the propshaft is not being pulled or pushed by the flex discs at either end.