W208 CLK320 rear diff question

[Sparks]

Hi all

New to the forum and first post so please be gentle with me

I have a 1998 W208 320CLK auto coupe. It's done 120k miles. I have had it for the last 5yrs/60k miles with no issues. All MB main dealer serviced etc

I have noticed a light clunck when I gently roll back onto the throttle after coasting - eg in slow moving traffic. Sounds like its coming from the back. When I turn the propshaft by hand I get more play then I would expect in the diff (both roadwheels locked/on the ground). The free play is approx equivalent to half a propshaft connecting bolt diameter on the diff input flange - eg about 6mm on a 100mm diameter. This free play does not move the output drive flanges at all so don't think there is a problem there. Note - it did have a new diff input oil seal at the last main service (2yrs/20k miles ago)

My questions are:

• Is this normal and just leave it or should I investigate further?
• Can anyone point me to an exploded view of the internal components?
• Are they DIY re-buildable or is it a pro-rebuild only job?
• Does any one know if this diff is the same as in any other models?

Any thoughts or similar experiences very much appreciated

Thanks,

Sparks

(West Sussex/Surrey)

 

[nick mercedes]

My questions are:

• Is this normal and just leave it or should I investigate further?
• Can anyone point me to an exploded view of the internal components?
• Are they DIY re-buildable or is it a pro-rebuild only job?
• Does any one know if this diff is the same as in any other models?

There's always a bit of play.

The diffs are shared among some other models, if it does turn out to need replacing good used diffs are plentiful and cheap...

 

[Sparks]

Thanks Nick

Has anyone heard of the rubber doughnut couplings between the g'box and the propshaft, and the propshaft and the differential, splitting up with age? Aparantly some backlash in the diff is normal and these couplings are know to fail when old and cause a clunk?

Cheers, Sparks

 

[jamesmc]

They have been known to fail due to age/high mileage, but to date not needed to change on on my car.

 

[1998K]

They have been known to fail due to age/high mileage, but to date not needed to change on on my car.

I've the same on my previous W202, that rubber coupling, I belive, on the transmission in way of the differential, and the Mechanic at Dealer sait it's OK only noisy going over potholes of bumps but only if in that moment you are without traction on the transmission axle (i.e. at idle)

 

[Sparks]

JamesMC and 1998K,

Thanks for the info

Sounds like what I am experiencing - it only makes a clunk when under neutral load (eg not under power or under engine braking - just when rolling from one to the other)

Looks like the rear one is fairly easy to get to and change but the front one seems lacking on access - Anyone done one of these or got any tips?

Thanks, Sparks