1983 300D vibration/shaking under load
 

I've been driving my 300d quite a bit recently, and starting to get a bit worried about the vibrations I'm starting to feel at 50-55 mph. They're not so bad that I want to stop the car, but I do notice that they are worse when I'm turning right, and almost go away when turning to the left.

The first place I'm going to try to look is the Flex Discs and the center bearing support thing for the drive shaft.

Could a bad wheel bearing or problems with the rear axle cause issues like this?

Thanks,

Joe

I think I would check wheel bearings first.

Jack it up, grab the wheel and move it back and forth.

I suppose a bad ball joint could also contribute.

Maybe even the nut holding the hub onto the car could be loose?

I would pop off the hub cap and see what's going on inside there.

I'll check out all the wheel bearings first.

The vibrations do seem worse when I'm accelerating, and that's why i was considering the Flex discs.....it doesn't really "clunk" when going into forward or reverse.

Could very well also be an axle. Easy to visually see if any of the boots are torn. However I have an issue on my '79 were I get a vibration/noise on the highway from the pass. side axle despite the boots being intact. It's worse when there are passengers in back or a trunk full of stuff. I know it's the axle because it got really bad recently, sounded like a flat tire, so I pulled off and the inner can by the differential was smoking!

It is now parked and I have an axle ready to go in...

So just because no boots are torn doesn't mean it can't be an axle, is what I'm getting at. If you check the bearings for play and find them to be OK then you may need to pull the axles at some point along the way in diagnosing it. It's much easier to test for excess play with them out of the car.

If the shake is in the car, it could easily be an out of balance tire...

If the shake is from the engine, look at new motor/trans mounts...

Last night I got the car lifted off the ground and checked all four wheels.

Both front tires had movement when I grabbed them at 12:00 and 6:00 and pushed/pulled. I guess that means bearings are shot there.

On the back, only the left side tire had the same looseness. So I guess I should just replace all 4 bearings and be done with it.

The flex discs looked good and didn't seem to have any major wear to them that was visible to my untrained eye.

One more thing,

When I had the rear wheels off the ground and I tried to rotate the tire, is it acceptable for there to be some play when I just start to rotate the tire? I noticed that the axle didn't start moving at the exact time that I started to move the tire.

I noticed that the axle didn't start moving at the exact time that I started to move the tire.

You could have play in one of the CV joints. Bad bearings will usually make a tremendous amount of noise before you notice any play. The play in the front wheels could be worn ball joints.

I don't notice any major noise from the bearings.

My brakes squeal, and I have a small sound when I first start off, but otherwise, nothing.

Update
 

I did notice something yesterday when I was out driving the 300D. When I turn right, sharply, like swinging it into a parking space at the store, I get a pretty decent squeal. It's not a tire rubbing or anything like that, and it doesn't happen when I turn left and do the same thing.

Any ideas what that might be?

Thanks,

Joe

May be an alignment issue....had a sound like that after I replaced a tie rod and was driving it to the shop...

Update
 

Just a quick update on this one....I have parked the 300d in the garage, for fear of doing major damage.

I was driving it home on Saturday, and coming up a fairly steep incline, and as it was accelerating in 3rd gear going about 50, the vibration was pretty pronounced, and I KNOW it's coming from the rear end.

That is all par for the course so far with the car, so I wasn't worried....but what DID worry me was the surging I was starting to feel as it was trying to accelerate. It almost feels as if the rear end is slipping or something.

At this point, I really think my major issue is something in the rear differential and/or axles. I think I'm going to have to find somewhere to take the car, as I don't have all the special tools to re-do the rear bearings. I don't know how much I need to take the axle halves off.

Anyone ever experience that surging going up hill like that?