Knocking sound from back of car!!

[BenzComander]

Hi everybody,

Been away for a while, but back now and hoping somebody can help!

My W210 E320 has a knocking sound from the rear end. It only occurs when the car is coasting (i.e. not on the throttle and not under load) at about 5mph. It seems to be consistent with road speed.

When I apply the brakes or accelerate the noise stops. Please can anybody point me in the right direction ( Please let it be a driveshaft joint and not the diff )

Cheers,

 

[stwat]

For a start, you might want to check the rear propshaft bush(where the propshaft joins the diff) Mine was so worn i got very bad vibration at speed(the last owner towed a very large caravan!!!!!) but yours could just be showing the first signs of ware(sp?).

Also check the driveshaft cv joints. One of mine started to tick and knock the other week and when i investigated i found the inner cvj was almost totaly dry on the drivers side!!!! I bought a cv joint regrease kit from hellfrauds(very recomended BTW, it is a presurised can of graffite based grease with a long nozzle that you can push into the rubber boot of the cvj to regrease. It also comes with tie raps so you can reseal the boots after you have removed the origional seals. Which you obviously have to do to check the cvj's) Mine are now silent and id recomend you(and anybody else for that mater) to regrease yours anyway. A can of this stuff @ £3.49 is much cheaper than a cvj/driveshaft for sure!!!.


Stu

 

[KillerHERTZ]

I would have thought it was the propshaft at 1st, See my thread:

http://mbclub.co.uk/forums/showthread.php?t=16372


But im 99% sure this is your trouble:

http://mbclub.co.uk/forums/showthread.php?t=14121

Turns out I needed 2 rear dampers fitted, press down on your car above the wheels and see what happens

 

[BenzComander]

Thanks for the help, local garage ran it up and down the road - "It's the diff mate!!"

I'm not so sure though. Forgot she had a prop shaft so will need to take a look at that.

Maybe time to call Chris Gray in Wendover for a diagnosis. Will let you know what happens.

Cant be rear dampers as it's an estate.

Cheers,

 

[BenzComander]

Had the car road tested by Chris today, and it stumped him!!

Never heard that noise on a W210 estate. Is this good or bad I asked, not sure he said!!

So car is going in next week for a look, keeping fingers crossed

Will keep you posted.

 

[grumpy]

Hi All
20 miles from home, a thump then ticking noise from rear. Thought had a puncher, stopped but all OK. Carried on at 40mph for 2 miles till ticking got loader. Stopped and had a look at diff. to see loads of oil on it's near side. Got RAC out to take us home. This morning jacked up and had a good look to find 2 drive shaft bolts missing and the rest all loose on the near side! The ticking was from the locking tab that should have been under 3 bolts but with only 1 had swung out and was hitting the body.
Question. Why did the bolts come loose and is it related to the oil seal leaking on the same side of the diff?

W210 E320CDI 2001

 

[BenzComander]

Been away a while again!! (Not inside I asure you!!) Just wanted to close this thread.

Turns out the thumping noise was from the rear springs corroded/seized in their seats. So when the car was going up and down they were twanging in their mounts!

Chris Grey took them off, cleaned the seats and lubricated thema nd now all is fine!!

HTH!!