300E - Front End movement
 

Cruising at 60-65, car tracks straight, all seems fine. If I accelerate or de-accelerate slowly and smoothly, the car continues to track straight.

If I accelerate fast, the car seems to literally pick up it's front end and shift over a few inches to the right. It continues to track straight ahead. A very strange feeling.

If I remove my foot from the pedal after this rapid acceleration, the car seems to drop down and to the left, back to it's previous position.

While I know the car could use new struts, what else could cause this? When we inspected the car yesterday, we had it on the rack. I shook the front tires back and forth, etc. Didn't feel any movement. The rubber boots on the lower ball joints are starting to go.

Again I feel this only with a rapid acceleration.

Thanks,
--Craig

I believe your problem is actually in the rear. The two links that go 45 degrees to the direction of travel cause the toe to change in the rear (under load changes) when defective. This causes the car to feel as if someone steered the car. You don't feel it in the steering.

Thanks Steve!
 

Hey, thanks for the quick reply. I will get it checked out. It looks like the differential mounts were replaced recently.

Regards,
--Craig

100% certainly the rear links. I have replaced four of six on my car over the last two years. Easy DIY 20 minute job. Partsshop can send you a diagram via fax or e-mail and you can choose, order and replace.

Good luck

Need clarification
 

My manual refers to 5 pull rods (spring rod, tension strut, thrust rod, camber strut and track rod). Are the rear links the thrust rods? Or while I'm in there, should I replace them all?

I was thinking about replacing the shocks with Bilstiens.

Thanks,
--Craig

At that mileage, i would be inclined to replace them all, but then I am pretty obsessive. Someone (Dalton???) posted this pic in the past, it may be of help.

http://www.warewolf.net/jelliott/arms124.jpg

When checking the arms/links, don't overlook the outer control arm bushing. These wear out and can cause simular problems.
[ They are comperable to where one would find a ball joint in the front, but are at the rear .]

With the car on all fours, grasp each rear wheel in turn at 3 and 9 o'clock. Shake vigorously back and forth. If you detect any movement, you have a problem. Further diagnosis to find the loose connection will require jacking up under the lower spring support arm to free the tire and keep the suspension loaded as it is while driving.

Steve

Better yet, have spouse sit in driver's seat, press brake lightly and shift from forward to reverse.

You WILL see the problem... Unquestionably.

do you need rear wheel alignment after
replacing all of the above?

Yes.

update
 

Had the rear end worked on last Friday. My mechanic did not want to work on it and he referred me to the most expensive shop in Orange County, Waited until I found a good mechanic through referrals.

When I shifted the car from forward to reverse and back as directed above, the rear axle would shift. We replaced the links, bushings, top differential bushings, subframe mounts, and shocks.

I can't believe the difference. The rear end is as tight as the day the car left the showroom. Now I am saving my pennies to R&R the front end.

--Craig

If you don't mind, I'd like to know what they charged you in the most expensive Mercedes shop in Orange County to do this job.

:)

Ken300D

Didn't go
 

I didn't even check Bruce Strauss out. My new mechanic is an independent. He charged approx $800 ($500 for parts and $300 for labor) for the work he did on the rear suspension.

--Craig