I have an 81 300D. The driver's side rear wheel makes a scraping sound. At first I thought it was brakes, but sometimes it would go away, so I just kept driving it as it was my wife's and my only car. On Friday I bought another car (Volvo, one year newer), and Sunday the Mercedes really started to scrape so I jacked it up on both sides and took off both rear wheels. All 5 lug nuts had been ground on the ends - almost like a grinder. It isn't too bad on the lugnuts - The threads are not affected, but something is definitely wrong.

With the lug nuts out, and the transmission in neutral, I can turn the driver's side rotor only with difficulty. It is not freewheeling. The passengerside seems to roll normally, but could use some lubrication, I am sure.

Am I in trouble? I have read the posts about emergency brakes, rear bearings, etc. It doens't seem to fit anything perfectly, But I am sure that there can be many symptoms of the same problem... I'm not looking forward to a bearing replacement, but that sounds like it may be it. Something is definitely inside the hub to be grinding against the bolts. (This is the rear hub and long bolts.)

It scrapes backing up, rolling forward, under acceleration, nuder braking, and seems to have a regular clunking at times, other times not.

I don't know if I should fix it or buy another Mercedes. This car has not been well taken care until I got it, has very low compression, won't start in the winter, has an unexplained oil leak, is full of rust rattles like crazy. But I love it. And I want another one jsut like it. Well, in better condition, maybe.

Josh - find another
 

300D in better condition and use your existing car for parts if necessary.

If that is not an option I would start by looking in the rear differential and see what is going on, next I would pull the axles and see what I've got. This job will eat up some time if done right and that is the only way you want it done.

The thing about a job like this is while you are in there you may as well replace alot more parts than just what you intended to replace to resolve the issue. What condition are the suspension parts in overall? At this mileage you will definitely want to look at this hardware real close and replace the worn items.

Disassembling and reassembling a suspension/drivetrain assembly is a job not to be taken lightly.
Jim
'85 300D
'95 E320
'97 CRV

Thanks Jim,

I was afraid of that... Do you have any idea what the problem might be? Is it the bearing? Can I replace it with a used component e.g., used hub, axle, and get through til next spring?

I really wanted to keep this one for a while. I don't think this one is worth replacing any of the suspension on. While I had the wheels off yesterday, I could wiggle the stabilizer bar where it was attached to the frame and could see it was coming apart there - there is a lot of rust underneath - I am afraid to chack the car up with the OE jack because those receptacles for the jack do not look very solid. I had a friend weld in a new floor as it was rotted and rusted through.

My goal is to keep running til spring '02 and then have saved $5k to get a near mint W123 Station Wagon.

Thanks for the reply does anyone have any ideas?

I don't know if this fits your situation, but if you use lug bolts from aluminium wheels with steel wheels they will make contact with the emergency brake parts! If you think it is the rear wheel bearings the best bet is to replace the trailing arm / hub as an assembly. About $100.00 used from a place like Atlanta Stugartt.

Bob D.

I think waterdiesel has it correct with the lugbolts, but I sure don't see the point of buying a used control arm and used bearing and dealing with the spring for more money than a new set of bearings.

It will take a special tool to do the bearings, but break down and let your local tech feed his kids instead of going to so much trouble to install a used bearing.