Help - whinning C class

[wingco]

I would appreciate any help or advice on the following-

W202 C250TD auto saloon 130k miles 1997.

The car developed a whine recently, I think from the back end. Last week I jacked up all 4 corners and span the wheels. I found that the rear wheels were making a "grinding" noise when turned (car jacked up, in neutral, parking brake off). I took the wheel off, and took the pads out. Noise was still there. Tapped the drum with a hammer, and the noise went, so I reckon that the shoes were scuffing the drum. I applied the parking brake and released it several times, and it worked OK, no scuffing or grinding noises. Whinning noise gone (quiet again on the motorway).

Today Whinning noise came back. Jacked up the rear of the car, now a very slight scuffing noise when the wheel is turned (also the noise is not consistent - now "on/off). The noise is not as bad when turning the wheels, but just as bad when driven, especially from 40-65 (when the road noise takes over).

The diff has a slight weap, but the levels are always OK.

I think the bearings are all OK (no movement). Gearbox OK (just had ATF change). Surely the diff has not worn out already?

I rarely use the parking brake, so I dont care if it works or not. But why would the shoes suddenly start dragging on the drums? Could it be a cable problem, or something completely different? Should the shoes touch the drum at all when released? Have I got warped disks (although they were new 25K miles ago + pads). Should I try and adjust the parking brake?

Help!

 

[kit820]

I share a similar problem on my 1996 w210 e230. The vehicle has only done 50k and has FSH with the local main dealer. I noticed the problem long ago but each time I went for my servicing, I always forgot to mention it to the mechanic. Having said that, there was no indication that anything was wrong with the car as each time it was being looked at by the mercedes dealer (who is out there for your 'arm and leg', thus keen to look for any defect) nothing has really cropped up except from some brake pads, but the whinning noise persists. I shall have the car looked at again and will ask then.

 

[MondeoMan]

The fact that the noise disappeared when you fiddled with the brake shoes makes them a prime candidate. If they're dragging enough to cause a noise the wheel centres should be very hot after a run, have you checked? Diff seems unlikely; propshaft bearings/UJ wear? Wheel bearings?