87 300TD scary wobble at speed and bumpy road - PeachParts Mercedes-Benz Forum

1stbenznc · #1 01-30-2011, 07:48 PM

Well- I bought another 300TD recently. I'm still not finished with the first. I guess I'm addicted now

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The car is really sharp, drives well, strong engine, but one issue is that while accelerating on bumpy, slightly curving roads, (between 45 and 70), I will occasionally get this sensation and "wobble" that makes me think that I am going to loose control. The car sways sharply side to side (like a loose wheel)

-It drives fine on the straight highway and streets
-The wheels are on tight and no wheel bearing play
-There is no play in the steering wheel/box
-The front strurts were replaced a couple years ago with Blistien comforts
-Springs are in tact
-Does not pull much at all on straight roads (good alignment)
-Wear pattern on tires is good.
-Tie rod links seem tight and replaced recently

I'm at a loss. The only thing I can think of is that horizontal shock along the steering linkage. What is that? Could that be the issue?? I think it is some kind of stabilizer, right?

Any help would be great!

vstech · #2 01-30-2011, 08:09 PM

inspect the rubber connected to the rear subframe, and all the front control arm bushings.

jonbobshinigin · #3 01-30-2011, 08:14 PM

If you feel the out of control notion from steering wheel while going over a set of rail road tracks or something, I would look into the steering damper. That is the center link that to which you referred.

babymog · #4 01-30-2011, 08:39 PM

As above, start with the rear subframe bushings and all rear links.

layback40 · #5 01-30-2011, 09:13 PM

If the whole car appears to be shaking then its a good chance its in the back end. If it is just the steering wheel that is being shaken then its probably a front end issue.
When you check things you need if possible to have the part of the car being checked supported on a stand under where the spring is. This insures there is no load on any suspension or steering components. A joint or bush may appear tight if its under load, when you hit a bump, momentarily parts of the suspension/steering have no load on them & if loose can start to shake.

Crazy_Nate · #6 01-30-2011, 09:39 PM

http://www.peachparts.com/shopforum/showthread.php?t=202416

http://www.peachparts.com/shopforum/showthread.php?t=264462

Good luck

RichC · #7 01-30-2011, 10:07 PM

I have run into several, not quite round tires, that have caused some weird symptoms.

I had checked the tire balance and it was ok.

Had me chasing problems all over the suspension.

Barely lift the wheel off the ground, where it is still touching just a little bit but you can still spin the tire.

You should be able to tell if they are off.

1stbenznc · #8 01-30-2011, 10:39 PM

Thanks for the input!! I will be checking the rear thrust links, tires, control arm bushings and steering damper tomorrow, and will let you know.

scottmcphee · #9 01-30-2011, 11:56 PM

Here's what I check in this order: rear shocks, transmission mount (not spongy), drive shaft center bearing (rubber intact and attached all the way around), flex disks (cracks and missing bolt/s), and all tie-rod ends (park the car and have helper steer slightly left/right alternate and see that there is zero free play - wheels move with rods).

I had a slight wobble at about 55mph on curves like you say... felt in the seat and on the wheel. Turned out to be center bearing and tranny mount, replaced and wobble gone.

Aquaticedge · #10 01-31-2011, 01:23 AM

I'd check all rear suspension components. Just a couple control arms will cause the rear end to wobble at times.

1stbenznc · #11 01-31-2011, 02:14 PM

UPDATE! - The good news is that I fixed the problem and it didn't cost me a penny to do it

. The bad news is the car almost killed me since the rear wheel was about to fall off!!!

When I said I checked the lugs to be thight, they were. I only checked the front for bearing play since the wobble seemed to be the front going crazy.

When I lifted left rear I immediately saw what was going. As soon as the wheel got off the ground I could see it totally move. The wheel was completely loose from the hub/axle. That main nut in the middle had worked its way loose!!! "Holy Crap", I said, as my jaw dropped and my life flashed before my eyes. That wheel was ready to come completely off.

I was able to tighten it up and pinch the nut in the grooves. I can see where it had been pinched a few times before and wonder if this happen with the PO too.

Hopefully there was no damage to the bearing. I don't think so. It drives as it should now. I checked all the rear links and bushing, and looks good and tight for the most part. Lucky me!

Aquaticedge · #12 01-31-2011, 03:03 PM

Glad you caught that that in time!

layback40 · #13 01-31-2011, 07:15 PM

I would keep an eye on it from now on. Dont know what the correct tension is on it, some one I am sure will tune in. I have had this type of problem with a completely different application. It was caused by a slight misalignment of the hub that caused a constant very small uneven load that would eventually break the nut free. Best keep an eye on it !!

Good Luck !!!