Driveshaft Center Bearing Damage

[IanAtkins]

Hello. I've had issues with my vibration problem, and am looking at the drivetrain.. DRIVESHAFT VIBRATION | Transmission and Driveline

Neville Wright found out that my driveshaft was 20deg out, and the center bearing was worn and cracked.

He's re-aligned the driveshaft, and replaced the center bearing but this has not cured nor made any difference to the vibration.

So my question to the forum is 'what would cause damage to the center bearing'?

The driveshaft has not yet been balanced.

Thank you..

 

[nocfn]

Engine and transmission mounts replaced?

 

[jhodg5ck]

they do just Wear out with age...

there is a possibility that work had been done to your drive shaft already and the shaft was balanced out of phase...wouldn't be the first that I've seen come in as much.

Find a driveline shop, have the unit balanced again. If you want to do some home brew balacning you can use BIG hose clamps. You'll want to leave the heat shield off while doing as much;-)


What wheels/tires are you running? If it's a square setup move front to rear etc..

jono

 

[IanAtkins]

thanks guys. yes motor/trans mounts all new.

I found a site that discussed driveline vibration for an 210 e55. After YEARS of hassle, an owner solved a persistent vibration problem by removing the 2mm shim in the front of the transmission differential mount.

After that, 2 other owners with the same problem solved theirs by playing with the same part.

 

[IanAtkins]

http://workshop-manuals.com/mercede...propeller_shaft_alignment/tool_set/page_6222/

http://workshop-manuals.com/mercede...propeller_shaft_alignment/tool_set/page_6225/

 

[IanAtkins]

all the 3 owners who fixed their vibration with the method above did so by removing the factory-fitted 2mm spacer, i.e. raising the diff. I wish I could refer you to the pages in the UK MB club forum where these guys expressed their "eureka" moments, but for some reason MBUK have taken those pages down.

I'm going to go with Jono's suggestion to rebalance the propshaft. After having discovered the misalignment, corrected it and replaced the centre-bearing, it would be illogical to jump over the fact that the persistent vibration may be that the propshaft is still out of balance.

Do you think that the at least 30+k miles driven on the car since the propshaft was replaced in the wrong alignment could contribute to it being out of balance now?

 

[195910]

Was the car imported from the Gulf ?

 

[IanAtkins]

no - Japan....

 

[Steve119]

Stupid question, but how can the propshaft be 20(!) degrees out? It should have fallen out of the center support by then?

 

[IanAtkins]

it was the alignment between the 2 parts of the propshaft that was out....

 

[r44raven]

Stupid question, but how can the propshaft be 20(!) degrees out? It should have fallen out of the center support by then?

Yep, I thought best not look stupid and ask ! But as the point has now been raised, between which two points was the 20% measured? It can't be between the two halves of the propshaft - that would be a huge variation.

 

[mercepor]

+1
And even more confusing (at least for me) in the previous post you wrote "Neville said that he couldn’t find the alignment markings on the driveshaft..."

 

[IanAtkins]

ok.. well me too was confused... Neville couldn't find the alignment markings on the first pass, but after I showed him the photos he did find them.

For the mis-alignment of the two parts of the propshaft, Neville notice a 20 degree misalignment the first time he looked, i.e. without finding the markings. If you imagine the 4-pointed claws connecting to the flex discs on each end, one end (let's say the transmission end) being 12 o'clock, 3, 6 and 9. According to Neville, the other end (the diff end) should be in between, i.e. 1.30, 4,30, 7.30 and 10.30.

On the first look, Neville noticed a 20 degree misalignment from that pattern, and he adjusted it accordingly. No change to the vibration.

On the second look - after he saw the markings - he observed that his (non marking) alignment was perfectly 108 degrees out.

So that means that the original position that the propshaft was in was even more than 20 degrees out!!

However, despite all these things going on, the tragedy is that the car still vibrates and that's really sad because you'd expect this stuff to be the cause and solution wouldn't you?

It's possible of course that a new balance of the propshaft after the alignment is now correct might just be the holy grail, but like most holy grails it's probably not where we expect it to be.....

 

[samiam44]

Ian,

All very good speculation, but we are assuming(maybe falsely) that the driveshaft was miss-assembled. Perhaps, the driveshaft tweeked a bit after a center support or flex disc failure. The mechanic maybe attempted to correct the issue by changing the alignment between 2 halves.

Just a random thought-

 

[mercepor]

When we worked on my car with its vibration issue we started to lift the car, run the engine and put the gearbox in D.
For us this low speed movements was enough to see that the center bearing is dead.
I know that yours is new and practically everything is new, but maybe you can see smthing "anormal" from under the car.
The driveshaft will move, one wheel also, you can catch it to make move the other one...

An other random thought

 

[IanAtkins]

Mercepor, thanks. Did you find your gremlin?

 

[mercepor]

Yes, center bearing.

 

[IanAtkins]

i envy you...

 

[Kyiv]

@IanAtkins, do you have an update, mate?