Frustrated:still C180 transmition noise at +60mph

[mearnsmerc]

My 2002 C180 auto estate has a noise coming from the tramsmition/diff when the car is accelerating (particularly going up hill) at between 55 - 70 mph.

Following helpful forum advice I changed the engine mounts and then the prop shat centre bearing (and rubber mount). However, neither made any difference. It was worth a try though, as both were relatively inexpensive and easy to change.

Last night I had the car running while the back end was on axle stands. I think the diff sounds noisy. The rubber couplings at either end of the prop look OK. I think the rear end clunks a bit when coming out of "P" into "D". Could this be related and also coming from the diff? Might it be the diff mountings rather than the diff itself?

Are there any further checks or steps I can take before handing the car over to a specialist.

 

[alancee]

could be duf dif

dont hand it over with an open cheque book yet ,some diffs are dear,some not,find out what ratio yours is ,it is stamped on the flat machined face that mates up with the cover plate ,top left or top right looking from the rear of the car ,it is not on any cast face,failing that use the vin on the rusky site but that can be inconclusive,best see it with your own eyes.

 

[carabind]

whats the milege ? and is it possible to do a diff oil chnage? I am 99% certain you will have checked the oil level there.

 

[amb67]

Haven't yet seen a Mercedes-Benz diff that hasn't leaked oil from all three seals.

Is your autobox oil level OK?

If yes, check the diff oil level and that the mounts on the gearbox and diff are OK. It shouldn't clunk when shifting from P to D, it's a Mercedes-Benz not a VW.

Let us know what you find?

 

[alancee]

spare differential if you or whoever needs it

if its your diff i have a spare guarenteed one you can have at £160.00,i bought the wrong ratio for mine,easy change on a garage ramp ,2.5 hrs max for a virgin,or anyone else for that matter plus pp though,ratio IS important ,like for like or very weird things happen that no one knows the answer to .

 

[mearnsmerc]

Just got car back tonight after having diff changed.Problem persists! So, have changed: diff, 2 rear tyres, engine mounts and prop centre bearing. Running out of ideas and patience now. Any new thoughts? Prop couplings? Although on inspection they look OK.

 

[alancee]

hi sorry you still having problems ,does the noise still happen if you tip change to another gear at that speed?

 

[Xtractorfan]

Are you sure its a diff noise / gearbox noise ..have u checked your exhaust ..this is more liable to vibrate on hilly acceleration.ensure it isnt fouling on the underbody/drivetrain and that all mounts are in A1 condition

 

[mearnsmerc]

Changing gear by tip makes no difference, nor does switching off the ESP. Took the car back to the garage who did the diff. They are now changing wheel bearing! I'm not confident about this - the noise does not fir the pattern of wheel bearing problems I have experienced in 20 years of fixing cars! Will let you know result tomorrow. Exhaust etc are ok

 

[mearnsmerc]

Just been back to the garage who fitted the new diff. They have now consulted a transmission specialist who says that the problem is in the gear box. Apparently a common problem with W203 Mercs is the Auto transmission oil being contaminated with coolant due to radiator internal transmission oil cooler failing allowing coolant to mix with auto transmission oil. This is causes judder or vibration in torque convertor and eventual failure. The transmission specialist recommended a new radiator and gear box rebuild at a cost in excess of £2500! Are others aware of this common fault? My question now is whether the damage gas already been done in the gear box, or if the contaminated oil is only causing the current problem? Am I past the point of no return on a new box?

 

[stuartmcd9@msn.com]

hi i have a simillar problem with my c180.The oil has been contaminated due to a fault with the radiator.I am going to change the radiator this weekend and flush the oil oil from the gear box.I have been told if it has been caught in time it might be ok.

 

[alancee]

hi i have a simillar problem with my c180.The oil has been contaminated due to a fault with the radiator.I am going to change the radiator this weekend and flush the oil oil from the gear box.I have been told if it has been caught in time it might be ok.

i have a good torque converter for your car should you need it

 

[Guy20]

Take the sump pan off and inspect the fluid if its not to bad contamination, then you may be lucky and not need a gearbox just do a couple of oil changes and filter in the gearbox to clean out the torgue converter, replace radiator and flush the pipes.

Its well worth an idea have done this on alot these and has been fine.

How many miles have you driven with this noise?

 

[alancee]

Take the sump pan off and inspect the fluid if its not to bad contamination, then you may be lucky and not need a gearbox just do a couple of oil changes and filter in the gearbox to clean out the torgue converter, replace radiator and flush the pipes.

Its well worth an idea have done this on alot these and has been fine.

How many miles have you driven with this noise?[/QUO

whats the cost on this gamble? ,hang on phone a friend