castroadan

Hello guys, I recently had to replace the front axles on my mercedes. Also just replaced the front drive shaft.

I get vibration when accelerating on my 4 matic. any idea what it could be?

alx

Transmission mount? Engine mounts? Bad replacement driveshaft?

castroadan

It happenend with the previous front drive shaft. And previous axles. I replaced the transmission mount. But maybe it is the engine mounts?

GPrime2

Engine mounts would show as more significant movement of the engine when you rev, regardless of the car moving or not. You can have someone rev the engine with the hood open and look for the engine moving more than normal when the rev starts.

does it happen when accelerating at all speeds or only specific ranges (is it different from 10-30 vs 50-70)?

castroadan

It doesn't it from 0-100. It doesn't matter how fast im going. Soon as I acxelerate it the steering and car starts to vibrate. Like if it is coming from the axles, drive shaft etc. I guess I shoild suck it up and have mercedes diagnose it.

alx

You sure the shake is in the steering and not in your seat? It could be coming from the rear... ask people seating in the back if they feel it. If they do- it is in the rear.

castroadan

Just took it for a long drive and it does seem to be coming from the body. So I am guessing it my be the rear axles or rear drive shaft?

alx

check rubber cake/ twist bushing in rear axle... also check rear suspension bushings - lower control arms are usually the culprit

castroadan

Ok thanks so much for the update, I'll check it out or take it to my shop to look at it.

Thanks a lot again

The Thomas J

I had a slight vibration in my E class and S class at acceleration and both times it was a control arm.

castroadan

Rear lower control arm?

castroadan

So my mechanic just called and told me he did feel a little play in the axles that were just rebuilt and replaced by him. He is going to take them off and send them get rebuilt again by the company he used. All parts and labor under warranty. I told him the body was shaking so I thought it was the rear. But he said he wants to eliminate that first and then work his way back.

alx

a play in the cv joints will result in clicking/ knocking when going over bumps...

but if he can eliminate those as the source of the vibration - sure... by all means...

castroadan

yeah I was thinking the same thing but I doubt that is going to take away the vibration when I accelerate. But atleast I am not getting billed for the labor again.

We will see what happens. I'll be with out the benz for a couple of days but its ok. I still have my SRT charger.

The Thomas J

Front. The vibration was in the steering wheel. It was very slight.

castroadan

well there was a very small vibration on the steering so it is good that they will rebuild or refurb my cv axles at no cost to me.

Once this get settled then they can work their way to the back, because I def feel the vibration on the floor and not the steering.

I'll keep you guys posted.

boardboy330

Interested...I am having the same issue. I have not went through all the ball joints but IIRC when my w211 did this it was a control arm problem.

castroadan

Which car do you have that is experiencing the same problem?

I called my mechanic last night and he is still waiting on the axles to get rebuilt. So it probably won't be till next week till they are in.

castroadan

So I got my car back from the shop this morning. Took it out for a drive and I say the vibration was reduced by 40%. I still have a vibration when I accelerate so I will take it back after the holiday again.

boardboy330

Sorry, long weekend. I have a 2007 S550 4Matic. I had the vibration before I installed 20" wheels. I ordered engine and transmissions mounts this weekend and will be doing an install. Also ordered a new sway bar and end links - occasionally hear a clicking or metallic bump over bumps.

castroadan

He suggested to replace the motor mounts and transmission mount. I already replaced the transmission mount myself since it was pretty easy.

Are you replacing the motor mounts your self?

He quoted me around $450 in labor for motor mounts and tranny mount.

boardboy330

Yes, I have a lift and full shop of air tools. I haven't done the W221 yet, but the w211 (E Class) was always a 30 minute job per side. I assume it will be the same for this car. Guess I will find out.

castroadan

Awesome, please take some pictures and let me know what tools you use so I can determine if I can do it or not. I'm pretty decent at turning wrenches.

Keep me posted.

alx

http://www.mercedesmedic.com/diy-eng...mercedes-benz/

this is pretty decent non-dealer sanctioned procedure...

MercedesLondon

I have a similar situation with my W221 2012 S350 AWD which has suddenly developed a vibration under acceleration but is smooth as silk otherwise.

If feels just like a badly out of balance wheel or a bent wheel rim. Had the wheels re-balanced and checked them all with a dial gauge with no noticeable out of alignment at all. Also checked all drive shafts and prop shaft couplings with no play anywhere . Car has only done 50k miles so should be no real wear anywhere.

Vibration is more felt at low speeds, i.e. from 40 to 60 more than 60 to 80.

Vibration is not felt in the steering wheel at all, and more through the whole car like a really out of balance rear wheel.

I notice also that there is a slight vibration noticed at idle but only when you put into Drive or go the other way from Drive to Neutral/Park. It can happen either way but is always totally smooth when not giving out the slight vibration. Could the total problem(s) be engine or transmission mountings? the trans mount seems OK as it is easily seen underneath but the engine mountings seem impossible to check without a lot of dismantling and most likely are best just changed if deemed to be the possible cause.