Help on Driveshaft Center Bearing/Holder Replacement

[pez]

Hello all. I need to replace my driveshaft center bearing and support piece....the bearing is fine, but the rubber support has aged and now allows the driveshaft to move around too much under heavy acceleration.

Anyone out there done this job and have any tips?

[Bandolero]

1, Use a hoist
2, Remove exhaust
3, Remove protective plate
4, Loosen Large nut on the front shaft
5, Remove bolts that hold the flex plates, remembering which way round they go
6, Slide front shaft rearwards
7, Remove complete tailshaft
8, If there are no marks to show the relationship between the two shafts, MARK them so that you can put them together the same
9, Replace bearing, bearing carrier and if the flex plates are showing ANY cracking, replace them.
10, Best to replace the flex plate bolts anyway.
11, Check the universal joint for free movement
12, Re-assemble

(Now what have I forgotten?)

I watched my mechanic do this only a few weeks ago.
I was too lazy and didn't want to get dirty. (Plus I have no hoist.)

[Big_Richard]

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[koan]

Just as Bandolero says.

I'd add mark every thing from the transmission output shaft to the diff input shaft and put everything back aligned the way it was.

Think I had troubles with handbrake mechanics in the way.

The book says to tighten the large nut with the car supported on its wheels.

There are centering sleeves at both ends of the shaft which are probably OK but have a look anyway

The flex plate holes have raised lips round them, ensure they seat in the recesses in the three legged spider pieces.

It doesn't matter which way round the flex plate bolts go in despite what other forums say - which contradict the illustrations in the book. Think three of the diff end bolts will only go in one way anyway. Just put them back the way they came out.

Not sure about needing to replace the 12 flex plate nuts and bolts but if you do get the same grade from the local nut and bolt shop, not M-B, they will be much cheaper.

koan 

[Bandolero]

Thanks Patrick, I was hoping I hadn't forgotten anything.   

[pez]

Hello! I have just returned from changing out the driveshaft center support bearing and mount.  Thanks so much for your advise.

I am lucky enough to have access to a lift, and this made the job much easier. I was able to complete the whole job in 3.5 hours. I would say that if you have a lift, it is not that hard at all.

My flex disks were in good order, so they did not need to be replaced.  Plan ahead to fight with your exhaust system, unless it is brand new - I actually was unable to remove mine, so I used an engine support stand to hold it up where at the rear most portion of the down pipes [so as not to snap exhaust manifold bolts] and simply bent it down from there.

It is also not totally necessary to even remove the front half of the driveshaft [I have a '76, later years have a clip that keep both halves together I believe].  The whole assembly [rear driveshaft] was easy to simply slide out the back.

Besides the exhaust aspect, the only other semi difficult portion of the job is pressing the new bearing in to the carrier.  I used a vise and some very large front wheel bearings [not Benz] that happened to be laying around the shop.  They were sized perfectly and allowed me to press the bearing into the carrier smoothly and evenly.

If anyone out there does this job, it's also a great time to replace the trans mount, too [I had done that about 3 weeks ago].  In fact, if you needed to do it, this process lends itself to changing out the flex disks, trans mount, center bearing, center bearing support, and exhaust system all in one swoop.  I bet all those items could be done in less than 5 hours total.