Thumping in left front wheel, more around turns - PeachParts Mercedes-Benz Forum

imagesinthewind · #1 03-23-2011, 10:51 AM

I searched, just got more confused.

So, I thought it was a flat spot on the tire (and still could be, haven't swapped tires to find out) but it seems more like something else than a flat spot. Car did sit in one spot for 6 months with the tire slightly turned.

Either it doesn't happen at higher speeds or the thumping is so fast that the sound blends together and cannot be heard. Louder on turns. A slight feel to it but nothing big. I looked at all the stuff under there when I did the brake bleeding, but since I don't know that much about what I'm looking at, unless it was hanging off each other, I wouldn't have known if it was good or bad.

No banging in turns or when I turn the wheel at a stop, no grinding, scraping or other metal to metal sounds.

I do need new front tires. Would be nice if it was just a flat spot.

Oh, and what is the name of the shock that is horizontal between the front wheels? Mine if bad and causes the steering to rattle. Would like to get that fixed. Could that be related to the new thumping sound?

Thanks,
Ginny

Alex300DT · #2 03-23-2011, 11:05 AM

Mine is doing kind of the same thing right now, sway bar bushings are decentigraded, not sure what else it could be, the best way i found out to diagnose weird suspension things like that is sticking a helmet camera under the car and driving around.

leathermang · #3 03-23-2011, 11:14 AM

I had a pickup truck lately which had a serious thumping sound....
and it turned ( pun ) out to be WARPED like I have never seen before...
so if you can jack up the car and hand turn the wheel/rim that would be cheap place to eliminate first...
' steering damper' for the horizontal shock ?
One good test is to have someone else drive the car in a four lane road...
and you be in another car just looking at the movement of the tires... this has saved me a couple of times on diagnosing stuff...

Biodiesel300TD · #4 03-23-2011, 11:31 AM

This probably isn't your issue but my wagon had a thumping in the front when turning. It turned out that the wheel weight was rubbing on one of the steering components when the wheel was turned most of the way. The car had been in a front end accident at some point before my time, and something was probably bent just enough that the wieght was rubbing. Had the weight put on the outside of the wheel and no more problem. Look at you wheel weights at see if they've been rubbing.

leathermang · #5 03-23-2011, 11:34 AM

Quote:

Originally Posted by Biodiesel300TD

This probably isn't your issue but my wagon had a thumping in the front when turning. It turned out that the wheel weight was rubbing on one of the steering components when the wheel was turned most of the way. The car had been in a front end accident at some point before my time, and something was probably bent just enough that the wieght was rubbing. Had the weight put on the outside of the wheel and no more problem. Look at you wheel weights at see if they've been rubbing.

WOW, that is one of the strangest and most extreme ( but precise) causes I have ever heard of.... that the wheel weight could hit enough and long enough to make noises... but not get knocked clean off.... LOL
and to have the suspension bent that much and still be driving it ?

lutzTD · #6 03-23-2011, 11:44 AM

thumping on mine was a wheel bearing, but it was more prevailant at higher speeds than low. if you can jack up the front then a simple test for suspension is grab the tire and pull. side to side can be tie rod ends or bearing top bottom can be ball joints or bearing, both is usually the bearing or a really worn suspension

roundout · #7 03-23-2011, 08:53 PM

Quote:

Originally Posted by lutzTD

thumping on mine was a wheel bearing, but it was more prevailant at higher speeds than low. if you can jack up the front then a simple test for suspension is grab the tire and pull. side to side can be tie rod ends or bearing top bottom can be ball joints or bearing, both is usually the bearing or a really worn suspension

For checking tie rod ends, when you say side to side, do you mean front of the car towards back of the car with the wheel and tire at a "zero steering angle" or do you mean side to side along the travel of the steering? I am chasing a similar noise on my 300D. I'm thinking it's a wheel bearing because the steering doesn't seem to have much slop.

As has been mentioned, try simple things first. Rotate your tires and see if the noise stays or moves. If it changes, get the wheels balanced. I onces threw $500 at the front end of my Jetta (parts only, I do my own work) to find my malady being caused by an out of balance wheel.

Biodiesel300TD · #8 03-23-2011, 03:17 PM

Quote:

Originally Posted by leathermang

WOW, that is one of the strangest and most extreme ( but precise) causes I have ever heard of.... that the wheel weight could hit enough and long enough to make noises... but not get knocked clean off.... LOL
and to have the suspension bent that much and still be driving it ?

Yeah pretty odd. I had no pulling or odd tire wear so everything was aligned properly, but something was bent enough to cause rubbing. As soon as I took it to the tire shop and had the weight moved the noise went away.

vstech · #9 03-23-2011, 12:19 PM

Quote:

Originally Posted by imagesinthewind

Oh, and what is the name of the shock that is horizontal between the front wheels? Mine if bad and causes the steering to rattle. Would like to get that fixed. Could that be related to the new thumping sound?

Thanks,
Ginny

that would be the steering dampener.

Orv · #10 03-23-2011, 03:08 PM

Does it go away if you put your foot lightly on the brake? If so, could be the brake pad anti-rattle springs. At low speeds slight amounts of run-out in the rotors can repeatedly lift and then drop the pads, making a clunk-clunk-clunk noise. Stepping on the brake clamps the pads in place and stops it.

imagesinthewind · #11 03-23-2011, 05:26 PM

So, I'm jacking up the side, doing a push-pull on top/bottom as well as side/side?

Okay. I'll report back. Thanks!

Hubby came home last night and asked how we all (family) felt about the opportunity to live in India for three years. . .still trying to come to terms with the question.

Steering dampner. Could the fact that that has been bad for over a year be contributing to the thumping on the left front? If that hard to replace? Anything super special about replacing it? What am I going to do with my car if I'm in India for three years?

barry123400 · #12 03-23-2011, 05:41 PM

Your issue is probably just a tire with a flat spot or internal tire belt issue.

Go to india and send us back 240d engines that are turbocharged. A good supply of five speed transmissions if available as well. The engines where still in production there not long ago and may still be.

leathermang · #13 03-23-2011, 07:28 PM

We have a forum member there with one of those... steal his and send it back.

kerry · #14 03-23-2011, 09:03 PM

A bad steering coupler can make make a rattle too.

Where in India? Why? Bring back one of the Indian G-Wagon's with the turbo 616.

imagesinthewind · #15 03-23-2011, 09:17 PM

Quote:

Originally Posted by kerry

A bad steering coupler can make make a rattle too.

Where in India? Why? Bring back one of the Indian G-Wagon's with the turbo 616.

No rattle, just a thump, thump thump. . .

Pune, India. Tom's company outsourced some jobs and the team there needs some American leadership to make things run smoothly. They are very laid back and America and American companies are NOT. It's not for sure, we are in the research phase to see if it would be feasible for us and the company. It's a lot to think about and a lot to do. Heck of an adventure though!