strange scraping sound when corning from rear

[SilverSaloon]

Hi

... more tails of woe for me ...

thismorning when i was turing around a big roundabout at about 20-30mph i heard a loud scraping noise coming from the rear passenger side wheel that seemed to indicate it was affected by the movement of the wheel as the sound had a rotational type sound (if that makes any sense)

I stopped and checked it out - nothing on the wheel seems amiss and i jacked it up and the wheel didnt seem loose or anything.

i bumped the car up and down and didnt notice any strange noises from the suspension either.

any ideas? please dont say its the self levelling playing up!!

it was almost like if something was catching on the wheel at a certain point and then lifted and then caught again as the wheel rotated. but nothing was caught underneath or anything.

thanks

derek

 

[BlackC55]

Remove the wheel and see if there are any marks on the tyre, wheel or body to indicate any rubbing.

 

[Dieselman]

Is the bearing slightly loose allowing the disk to contact the backplate.?

 

[SilverSaloon]

Is the bearing slightly loose allowing the disk to contact the backplate.?

it failed the mot on a rear bearing (excessive play) on that wheel but the guy then said he tightened something and the play went away.

i have jacked the car up and wobbled the wheel up/down left/right to check for any play. All seems nice and tight - no obvious play.

 

[kth286]

Silversaloon

The rear bearings are not adjustable, so I would be very wary of that guy.

They are very difficult to change on estates - amd many techs remove the whole of the rear hub assmbly from the suspension to get the assembly to a press.

Needs a very specialised tool otherwise which has only recently (ish) become available.

 

[SilverSaloon]

oh dear

sounds like a trip to the $tealer for a wallet whipping is on the cards

surly if the wheel doesnt move when i try and move it with my hands then it cant be the bearings? or am i missing something?

whats the best way to test this on the rear wheels?

i adjusted the front ones no problem.

 

[grober]

My guess would be the spring clip which tensions the rear pads. It clips in behind the two pad locating pins and presses on the ends of the pads. They corrode quite badly and can often rub against the rear disc. They should be changed along with the pins every time the pads are renewed but often arn't.

 

[SilverSaloon]

i'm going to remove the wheel tonight and see if there is anything else i can look into.

i've changed the rear pads on the saloon and know the metal spring plate you mention. I will check this out on the estate - maybe its worked its way loose or something? it does only happen on cornering though.....

i've never had the rear wheels off the estate yet.....

 

[kth286]

SilverSaloon

Is there any noise at all from that rear bearing when you spin the rear wheel ?????

 

[SilverSaloon]

i havnt spun the wheel yet (car was in park when i jacked it up). I only hear the noise as i turn a RIGHT corner (at more than 20mph) - cant hear anything when driving straight, turning slightly or turing a LEFT corner....

 

[kth286]

SilverSaloon

You need to get it into a position where you can spin the wheel - essential.

And then wiggle it in different posions around the circumference to see if anything is catching.

Much easier with the wheel on the car initially - than removed from car - as you will not be able to get leverage on hub only.

You will need to chock the front wheels with some pieces of wood.

 

[Dieselman]

The bearing is a regular plain bearing and with care can be replaced by removing the retaining circlip and driving out, then driving the new one in, taking care to only drive onto the outer race. Otherwise press it in using threaded bar as the puller.

http://www.detali.ru/cat/oem_mb2.as...GM=717.433&CT=F&cat=44R&SID=35&SGR=075&SGN=04

 

[grober]

There's a how to here http://www.mercedesshop.com/Wikka/W124RearWheelBearing

Except the guy basically dismantles the hub and takes it to a machine shop to remove /replace the bearing itself.

 

[SilverSaloon]

anyone have an idea how much a Merc dealer will/should charge for this job?

it sounds like they may be my only option as i dont have a specialist near me and it sounds like you need to know mercs to do it??

sounds a bit out of my depth.

 

[Dieselman]

Any garage can do the bearing.

 

[Number_Cruncher]

>> sounds a bit out of my depth.

I would probably approach it a bit like in the how-to. Any decent garage / machine shop will have a hydraulic press to press the old bearing out, and press the new one in. The rest of the work is fairly basic.

The only modification to the how-to which I would suggest is to fit a steel spare wheel (if you have one) to the rear wheel, and drop the car down, off the jack. Then, you'll be able to get in, and undo the tight driveshaft end nut, on the floor, rather than trying to stop the wheel turning in the air. You might be able to get in with the socket if you take the plastic centre out of an alloy wheel, but I haven't tried it. Having the wheel on the ground will also be helpful when finally torquing up the driveshaft nut.

 

[SilverSaloon]

ok, i've jacked it up again.

wheel turns fine (only scraping sound coming from the brake pads rubbing a little). It also appears the disc may be very slightly warped. is this a big problem?

the brake pad clip spring mentioned before appears fine. I scraped of the flakey rust around the edge of the disc with a file aswell when i was there.

wheel doesnt wobble at all as far as i can tell whilst turning.

SO - after i did all this, it still made a sound on my test drive, so i took it to Kwik Fit

they took it for a drive and heard the sound. they said it was the exhaust heat shield rattling.....

i got home, tightened all the bolts on it so its dead tight now.

i still get a swuelching noise. not sure if it was a groaning and now a squelching......

i am now starting to think its some sort of tyre defect?

i am going to put the spare wheel on temporarily to see if it still happens. i'll do this tommorow. i checked tyre pressure and its at 32psi which is what i always run it at so seems fine.

any idea if it could be suspension related?

i am worried about how safe it is.....

 

[grober]

Maybe you could get a couple of mates ( 0ne to drive, one to observe) to drive along behind you in another car to observe any unusual wheel /suspension movement during cornering? I suppose its possible you have lost one of the 5 x2 rear suspension arm bushes which is causing some sort of tyre scrub during cornering. Have you visually inspected all the suspension arm mountings? does the tyre exhibit any unusual tread wear pattern? Rear spring not broken? Rear anti roll bar links and mountings OK?

 

[bolide]

I'd check all five rear suspension links on that side. I wore out a rear tyre once when one came loose or the bush wore out - can't remember which, it was about 10 years ago

"Tightened up the rear wheel bearing" - tsk, tsk. Time to cross him off your Christmas card list!

Nick Froome
www.w124.co.uk

 

[SilverSaloon]

i'll check the bushes and suspension items tommorow for any obvious wear/breakage.

i did have a quick look today and the spring looked ok, as did the arms themselves. Didnt really take too much notice of the bushes but they could well be worn. I expect most of the bushes here are quite easy diy jobs without too much dismanling?

failing that i guess its a trip back to a garage again.

if it does appear to be bushes, do you reckon the car is safe to drive? i suspect the dealer wont have the bushes in stock....