W202 Noise

[dbanbery]

After sliding sideways on a hill and banging the kerb with the passenger side back wheel, a grinding noise has begun to come from the car when moving. it didnt come on straight away though - and probably was driven about 100 miles since with no noise, no problems. i've had a think and come up with these point and would like to know what people think:

it doesnt happen while braking

the only thing that alters the noise is accellerating - which makes it quieter.

as you go faster it either gets quiet or gets drowned out by road noise. on my 30 mile journey to work today there appears to be no performance or handling issues, and by the end of the journey the noise has go quieter...?

there appears to be no fluid on the floor where it has been parked and i can see anything underneath when looking briefly

you cant hear the noise from outside IE opening the windows while driving along.

the diff did do a lot of work in the day after the bump, it happened in the 1st 10 mins of my journey [people not stopping for a junction then i nearly got stuck! its always someone elses fault int it?] and coming back from work i spent 2/3 hours crawling and stopping then trying to set off on hills etc with sheet ice, lots of spinnny wheels whether it be one or both wheels. - it wasnt making the noise IIRC on the way bacj when i actually started moving properly

from these things i have ruled out brakes, suspension and gearbox and have begun to think its one of two things -

Differential cracked housing?

some sort of hub/drivehaft thing that has bent and is rubbing on something it shouldnt be.

i am going to have a look at the weekend at the underneath of the car to see if i can see anythign that is bent, broken or ground.

another possible theory from my dad is that salt ice grit has got clogged up on one of the wheels - ? i doubt that it wouldnt be still there after a 30 mile journey would it?

anyways

any advice or help greatly appreciated.

 

[television]

Sorry to hear your news,it would not be damage to the axle
though drive shaft somewhere

http://www.detali.ru/cat/oem_mb2.as...417717.418&CT=F&cat=44V&SID=35&SGR=030&SGN=02

Its more than likely around the brake area, and jacking up and spinning the wheel would tell you this

The backing plate may be bent 68 in the link

http://www.detali.ru/cat/oem_mb2.as...417717.418&CT=F&cat=44V&SID=42&SGR=045&SGN=02

When you can jack the car and spin the wheel, take care and do on level ground with parking brake off and put in N

Report back please

 

[dbanbery]

Television, thankyou for the prompt reply,

if it is the backing plate thats good news! but if so how come it is louder when cold, and didnt come on straight away?

its a manual too would that make anything different? 1996 C180 sport?

i'll check it out tomorrow when its light and i can do things to it

 

[television]

That question is too hard, once jacked you will soon see, I hope, it will only be something on that corner. The rear end suspension is quite strong and hopefully nothing bent,,maybe the wheel is bent, that can happen

 

[dbanbery]

yeah i'll check that in a bit, but there isnt any vibration at speed. it drives exactly the same as pre bump [still flat spots a bit when you floor it and there are still a few bulbs that need replacing in the dash] there is just this grindy noise.

The Alloys are genuine Merc E Class ones so i doubt whether they would have bent.

 

[grahamcol]

Hi and good luck with your 202. Wheel bearing perhaps ?

 

[dbanbery]

i've been out at lunch and the wheels are straight, they dont move when you manually wobble the wheel etc.

i have changed my mind where the noise is coming from and i think it might be the propshaft. do these have a centre bearing like on BMW E30s? if so then i think that might be the culprit... either that or something stuck behind it... strangely enough it makes the noise when reversing in accelleration rather than decelleration.. its going up on some small ramps tomorrow to investigate further but i'm hazarding guess at a centre bearing. any idea on cost? [going to check ECP/GSF sites now].

there is a small amount of damp on the bottom of the diff housing but it doesnt look like its dropped its fluid.... and dont they make a whiny-whiny-crunchy-crunchy-bang-lock-back-wheels when the whole unit melts down sort of noise?

 

[television]

Yes there is a center bearing on the prop and a flexi each end.

MB diffs do look messy as the hypoid oil foams when hot.

There are too many other components for it to have affected the diff

 

[turbopete]

might be worth checking the inner wearing faces or the rear brake discs. ive come across a couple of mercs now where the owners have complained of a noise at the rear end. the inner faces of the discs were pitted. new rear discs and pads, noise dissappears. unlikely, but maybe worth a look as the second one showed no signs of judder through the pedal when braking.

 

[dbanbery]

ok will do.... but it really does sound like its coming from the middle of the car... and it doesnt seem to change under braking at all. usually juddering get worse under braking or goes away dependant on problems but this doesnt seem to make any difference... i'm starting to think its the prop.

all will be revealed tomorrow!

 

[television]

ok will do.... but it really does sound like its coming from the middle of the car... and it doesnt seem to change under braking at all. usually juddering get worse under braking or goes away dependant on problems but this doesnt seem to make any difference... i'm starting to think its the prop.

all will be revealed tomorrow!

If you think it is the prop, jack one back wheel only and with the parking brake off and in N, turning the raised wheel will rotate the prop shaft

 

[dbanbery]

going to check that out too. i live on the steepest hill known to man so i'll need some big chocks.

 

[television]

going to check that out too. i live on the steepest hill known to man so i'll need some big chocks.

Nothing is flat where I live and I had my V70R sit down with no wheels one side, I was lucky as it only broke the roll bar, getting it up from the ground was something else

 

[dbanbery]

Right, check the pics:

Just testing the camera

Diff, bit oily but otherwise OK?.... would it be worth replacing that seal?

The offending item!

it wobbles about 6 mm when you move the shaft up and down. you can feel the space... its knackered.

sooooo,

the question now is.... what part is it ....? ECP have "propshaft coupling kit front" and propshaft coupling kit rear"

or.... is it "propshaft carrier bearing" ? my car is a P plate reg'd in 1997 but is a pre facelift declared manurfactured in 1996 - so i'm guessing i should work off the premise of it being a 1996. yes?

 

[television]

Thanks for the pictures,, would you like a DIY paper on how to change it

what 202 is it

 

[dbanbery]

ooh, theres a DIY paper? i was going to go at it tbh and see if i could get away without taking the exhaust off... there seems to be enough room in the place to get to the bolts on the bushing and there seems to be plenty of space to get to the diff bolts so one would think i might not... if i do then i might take the opportunity to do the exhaust cause the one on looks a bit ropey and there is a bracket bar missing where its fallen off.

 

[television]

It will take me 3 mins to print off and send a paper to you.

just want to know what 202 it is

 

[dbanbery]

PM sent !

to be fair, all i really need to know is if there are any special tools , whether the exhaust needs to come off, and whether the old one just slides off or has to be tapped [or repeatedly beaten] off with a hammer etc.

if you need an address repost

Cheers

 

[television]

I will print off in the morning

 

[dbanbery]

so thats kit, part number 89.

Television, does your signature link stock this part? i have emailed them requesting the part price without the part number but have had no reply as of yet.