I've had this '87 300e for a few months now, and am slowly fixing its issues. I bought this car for my 17 year old son to drive.

I'll try to explain as clearly as possible. A couple of weeks ago, I decided to take it in to our local guy (the only person here that works on MB).

When I left the drive-way, on acceleration, I'm getting this scrubbing sound coming from the rear of the car. Really loud. When I let off of the gas petal, it goes away. At first, I thought it was a brake pad worn out, but realized quickly that it wasn't. So I'm thinking...rear end? Well, the mechanic checked it out along with a host of other things and he said that the only thing he could find was a worn out shock. BTW, the scrubbing sound had subsided by the time I drove 25 miles to the shop. You can definitely tell that it is revolution related (changes with mph).

Any ideas??? wheel related? differential related? shocks?

THANKS in advance,
Don

 

aftermarket rims? i've seen alot of people put aftermarket rims and not check the offset..

worn parts in the differential?

 

could be your rear wheel barings.... mine did that too it was getting loud and stuff, and i almost replaced my differential and i had them open the wheels and it was the wheel barings.... put new ones on and its smoth as new

 

Everything's stock.

I wondered about the wheel bearings. It's not a "whine" like you typically here with bearings or rear end problems.

It definitely goes away as everything warms up. And only happens during acceleration.

THANKS

 

under load they stress and can hum,off the gas less stress they quiet down,rear wheel bearings would most likely be humming, load or not.look at the boots,torn?
ohlord
Boot kits at www.autohausaz.com
inner cv joint at http://germanstar.net/124ds.htm
if thats what it turns out to be

 

Thanks for replying. I'll do some more checking. It is definitely not a hum, but more of a scrub. You could easily mistake it for a brake pad worn down to the metal, only less of a metallic sound.

 

are you sure it's not the starter motor???? does it make that scrubbing noise when you change gears????

 

It's coming from the rear of the car. It is not a constant scrub, but more of a revolution thing. Like with every wheel revolution...scrub-scrub-scrub-scrub. Increased frequency with mph, only while accellerating, especially under 35 mph. The actual sound resembles the sound of a tire scrub.

Thanks for the help...Don

 

sounds like a caliper/brake issue to me.

 

Mine did that, but I could only hear it if the windows were down and I was driving past something for the sound to be reflected back. The brakes were good and since I rarely have the windows down I never worried about it. I figured I'd fix it when it broke, but the AC evaporator gave out first, and the tranny was next.

 

one thing it could be that is over looked by alot of people is the pump in the gas tank it might be going bad or the filter in the gas tank is going bad or clogged you should have that checked out.

 

...but then it wouldn't keep time with the revolutions of the wheels.

 

true but it cant hurt to have it looked at

 

wheel berings..didnt even think about it...thats what i would lean towards if everything is stock..

as for the fuel pump, i dont think i have ever heard a fuel pump make a scrubbing noise.

 

it might if the filter is clogged from trying to suck gas out of the tank

 

I found my problem today.

For those of you who suggested wheel bearing...ding ding ding, you win the prize. Just finished ordering them from autohausAZ.

THANKS for the help folks!

 

Well, I changed out the offending wheel bearing on Saturday.

WHAT A PITA!

1. Remove wheel
2. Remove axle nut
3. Remove brake caliper
4. Remove rotor
5. Remove parking brake and cable
6. Unscrew dust shield
7. Unhook all of the suspension rods/linkages
8. Slide hub assembly off the axle
9. Remove old wheel bearing
10. Replace bearing and reassemble

Sounds good on paper, but was extremely difficult for me. Getting the old bearing out was probably the most difficult. Not having a press, I had to improvize with the tools I had. The innermost inner-race did not come off of the axle hub/flange with the rest of the bearing, so after much frustration, I ended up cutting through 90% of the race with a Dremmel tool, then I tapped it with a chisel to break it. That procedure actually worked nicely. Installing the new bearing was a piece of cake. I have several large round pieces of metal, which worked well as tapping devices.

I read that the shops usually spend 3 hours on one rear bearing replacement. I used up more than twice that time, embarrassed to say. Now that I know how to do it, I think my install time on the other side will be much better.

 

Check autozone for the tools youll need.

They loan out tools for relatively cheap and the best part is you get every penny back when you return the tool.

I used them a lot when I was redoing the suspension in the front.

Ball joint presses, pickle forks, theyve got them. Theyll save you a big headache and possibly even broken parts.