I have my car in the shop. It is a shop I have used before and I do trust them. The car has a grumble vibration in first and a bit in second under moderate accelleration. It feels like running on gravel when the rocks slide out from under the tire. I thought it may be tires since they are worn. After replacing the old Generals with new Michelin PS 3+ the same vibration is there. The shop tells me it is the flex disc (I assume rear only) The cost is 2 grand. I see NeedsWings has them for $100. Is it really that difficult to replace? I see a few videos on You Tube for the bigger Mercedes passenger cars and it is just 2 wrenches and a pry bar; ignoring the car lift. Is this something easy enough to do in a drive way on a weekend? If so, is it just as easy as unbolt, pry apart, remove disc and installation is the reverse?

As for skills; I do not do major surgery on cars, but I can certainly replace an alternator, break pads and the like. I have ramps, jack stands, tools and a big enough pry bar. Is it a repair worth 2k?

 

Is it the center carrier bearing, not the flex disc?

I bet their price of 2k is a new driveshaft assembly.

The sound you describe, sounds like the rubber around the bearing worn and rattling the driveshaft under acceleration

 

They said it was the flex disc. The price may have been for a new driveshaft. My assumption is that we can just replace the disc and not need a whole new assembly. Is this a bad assumption?

 

Yes they can be changed by themselves with relative ease.

How many miles are on your crossfire ?

Before you order I would check the play in the bearing.
The u joint in the middle of the 2 piece shaft is non rebuildable.
Some change the flex discs and bearing and have to keep the joint, some just get a whole new shaft.
The bearings and flex discs are available, the problem is the pinned in u joint and no body has the tool to change a mercedes u joint.

I went a different route.

 

Thanks Speedy

It is a 2005 Limited 6 speed manual. Just turned 97k on the odometer.

Found this from another thread: https://wholesaleimportparts.com/Chr...shaft_2005.php

Looks like a new shaft is 585 and comes with the flex disks. Just over 25% of the cost from the shop. Assuming I can replace the assembly with the car up on ramp and jackstands.

 

Good find

Should not be a problem changing on jack stands.
As long as you have the right size of trox sockets .

Wonder why the manual shaft is $85 more, I thought they where the same.
Didn't think the props where different measurements mating to the trans.
I have mine sitting in my shop.

The srt has 4 arm props, but thought the N/A 's 3 arm props where all the same.

 

I would think it is the center bearing support on the driver shaft ,,, and not the drive shaft or the flex disk

 

What I thought also, how his description made it seem.

 

I have been on a business trip and have not been in contact with the shop since the initial call. Plan on talking to them in the morning. I’ll see if they will confirm if it is the disc, bearing or if they just think it is the drivetrain and want to replace it all.

i really appreciate everyone’s feedback. This forum is awesome.

 

A lot of service shops, even the independent M-B ones, will quote the entire drive shaft assembly whenever the center support bearing or flex disc needs replacing. It's the easiest repair to make. Just happens to be the most expensive, too.

 

Also covers them if they were wrong and the center support bearing was not the problem, plus they make more on the traditional markup for a more expensive part.

 

Just got back from the shop. They confirmed that it is the center bearing that is making the vibration, but that the flex disks are cracked. The quote for the driveshaft is almost $1100 and the flex disks are $310 each. Apparently the only center bearing they can find is from Dorman and that bearing only fits the Dorman replacement drive shaft and specifically mentions it will not fit OEM.

I am waiting to check with the owner to see if they will get the bearing and disks from Needswings, or the replacement kit from wholesale import parts. My feeling at this moment is that they don't want the hassle, so I will end up under the car in the driveway. Other than being a tad nervous at trying something I have never done before (not that big of a deal) I am more worried that I don't have a pit or proper car lift. I know you are supposed to have the car in neutral so you can rotate the shaft for bolt access. You are also supposed to torque the bolts down with the suspension under load. Trying to make that work with ramps and jack stands is making me feel like a contestant for this years Darwin award.

One more question for those of you with more experience at this than I have. Assuming this becomes a DIY job for me. I see 2 options:
Order center bearing ($99) and flex disks (2@ 99) from NeedsWings for $300
Get the whole replacement kit from WholesaleImport at $585

I can see benefits and drawbacks to each.

 

Thought the center bearing.
Would change the discs also.
But still chancing the non rebuildable and non serviceable center u joint.
For the 500, I would say to change it all.

You should be fine to change in your driveway.
As long as you have a hard floor to put jack stands on.
Changing a control arm and need to put under load before torquing down the bolts, but for the flex discs, you will be fine with the car on jack stands, not much to it.

I just went a different route when I did mine.
Now completely serviceable, lighter and no flex discs or carrier bearing.

 

This might be helpful,

 

Flex disc is a torx fastner and there are 6 bolts. Easy to do IF you have access to the bottom of the car, if raised up a bunch or a lift. Woody

 

Maggy, excellent find! Going to 'save' this vid for if I ever need to replace this stuff! TYVM!

.

 

Thank you all. Sounds like the replacement of the whole driveshaft is the way to go. I am going to see if the shop will get or use the replacement. If not, I'll try it myself. I will post back with results, but if I do it myself, it may be a while.

Thanks again!!

 

I am curious, what is the difference between the auto and manual trans driveshafts ?
I thought they where both the same.
But that site has a $80 difference.

 

Date: Wed, 14 Aug 2019 18:06:20 -0400
Subject: Re: Reply to thread 'Procedure for replacing flex joint?'
from Needswings U will get the correct parts ,,,

example e bay and parts store,, most flex disk the steel inserts are too big,, yes you can pull them in with a wrench but U may not get them apart later ,,,they are not interference fit.. when u remove the driveshaft look at where it slips joins one half of the driveshaft has 2 bumps and the other 1/2 has one bump this is the balance alignment ,( it is like take your left hand ,hold out 2 fingers and take your right hand and put your one finger between the two this is when you reassemble the driveshaft. jim
i though i posted this but 3 of my post have come back undelivered

 

Reading these posts re flex discs, I decided to replace them when doing the Centre carrier bearing (from Needswings) as the car now has 99000Km. Got Dorman flex discs from a supplier,( PN # 935-403) but upon comparison with the existing MB parts, they are NOT the same. The holes match up but the originals (MB # 210 411 0415 stamping) have protruding metal bushings that fit into the driveshaft on one side, and into the yoke on the other. Thus the MB bushings are 3mm longer than the Dorman bushings which sit even with the rubber. There is no way I am putting these on the car. The front and rear flex discs are exactly the same on my manual transmission 2004 xf. Mine show no signs of cracks, but feel rigid.
The Flex discs can be replaced fairly easily if you loosen the carrier bearing holder to allow some linear travel of the driveshaft.
My carrier bearing was absolute toast, the rubber had disintegrated. The only manifestation was a clunk when taking off in first gear, otherwise no symptoms. Glad I found it before a catastrophy. Only the rear half of the driveshaft has to come out to service the carrier bearing. That is good because otherwise the exhaust would have to be jiggered out of the way. I only let the heat shields droop down, and removed one little plate near the carrier bearing. The rear driveshaft and carrier bearing slips nicely down towards the rear. The front half of the driveshaft is trapped by the manual shift brackets not allowing passage of the yoke when trying exiting towards the rear. The exhaust prevents exit towards the front. I just marked the alignment, and left it in place. Getting the right parts is far more difficult and expensive in Canada. Between exchange rates and Shipping, we get screwed. I got some flex disc part numbers from this forum and I will try again to get them from the supplier. As for the Amazon parts, they have a dizzying number of different ones. With a little digging I found the exact MB part number listed from a Chinese source but I can't really tell from the photos if they have the protruding bushings. If anyone has had success in getting these exact right ones from Amazon, I would appreciate confirmation of fitment. When I am all done and back together, I will follow up with the final results and sources for general information and for my Canadian compatriots.