Greetings all,

I've recently noticed a very weird left-to-right "wobble" feeling when driving my '81 300D ('84 engine/trans). This only happens at very, very slow speeds, say for example when turning into a parking space or backing out of one. It also seems to only occur after longer stretches of highway driving, say 30 minutes or more.

My thoughts on possibilities? One, the engine mounts. I have new Lemforder mounts to install, but not sure that's causing it. There is some shaking when idling at a stoplight (sometimes worse than others), but not real bad. Two, the flex discs; perhaps they've gotten hella age on them (have no idea when replaced, if ever), and are causing driveline wobble, especially after a longer trip (rubber going through weird expanding/contracting phases, causing the wobble?). Three, the rear sway bar links; perhaps they've never been replaced either.

Look forward to other's thoughts and ideas as to potential causes and solutions. When I get a chance, I'll look at those discs and the sway bar links.

Could be as simple as a tire with a cord that has separated. Run you hand along the thread surface and feel for a bubble or uneven surface. One good pot hole or over inflating can cause it.

Quick fix, sometimes

I had one go bad recently; can't quite seem to get down to the wear marks anymore...I also had the wobble, suspected the tire- ran my hand around the tread- BINGO yep damaged belt! Changed out the tire, all good!

Cheers!

snapped_bolt

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'81 240D For now, a good place to borrow new parts
'80 300TD Probably will be put back into service!
'79 240D BACK IN SERVICE SINCE 09/16; limited use, oil leak. Guide pin r/sealed/replaced. Still a leak. Front crank seal....

I like the bad tire idea. I had a front tire with a broken cord that felt VERY strange at low speeds. A mechanic told me to take off each wheel and test roll them on my driveway, the bad tire would fall right over it was so out-of-round. Moved that tire to the rear axle while I ordered a new tire and made time for that to be installed.

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Respectfully,
/s/
M. Dillon
'87 124.193 (300TD) "White Whale", ~392k miles, 3.5l IP fitted
'95 124.131 (E300) "Sapphire", 380k miles
'73 Balboa 20 "Sanctification"
Charleston SC

Be very careful when running a hand around a suspected bad tire, sometimes steel belts fray and come through the tread surface.

Thanks for the tips folks regarding the potentially bad tire. The front ones are newer General Altimax (installed last year), the rear, some generic my Dad put on at some point in the past.

Couple of things; I assume from your comments this is likely related to the front tires, IF there is a problem with either (or both) of those? And two, my assumption is that it will be clear and obvious if there is a tire problem, because a definite lump or imperfection will be felt in the tire itself when running my hand all the way around over the tread. And 97 SL320, I'll be sure to wear some type of mechanic's gloves to keep from cutting myself on any stray steel belts!

We used to call that 'walk.' When a tire is damaged or has a manufacturing flaw it will cause the car to swerve from side to side. I've never seen it happen to a front tire but I've only seen a couple do it.

Ask the guys where you bought the Altimax.

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84 300SD
85 380SE
83 528e
95 318ic

Not too uncommon.

No, if a belt (cord) has separated or broken, it may not be visible or detectable by feel (but that doesn't mean you shouldn't inspect them closely while you have them off the car, check the brake pad thickness as well). Remove each front tire, and roll them on a flat surface. The bad tire will be VERY obvious. Check the rear tires if no issue with the front.

An old factory-trained (in Germany) MB mechanic shared with me that every time he worked on a car, no matter what the job was, training and practice required him to inspect all four wheels and brakes (safety first!) and no other work could proceed until any problem with tires or brakes was fixed.

__________________
Respectfully,
/s/
M. Dillon
'87 124.193 (300TD) "White Whale", ~392k miles, 3.5l IP fitted
'95 124.131 (E300) "Sapphire", 380k miles
'73 Balboa 20 "Sanctification"
Charleston SC

Had a broken shock once give me hell on a trip back home a few yrs back ,if the tire inspection plays out give the shocks a heavy hand to see if any movement side to side or broken shock mount or loose bolts.My experience was a feeling of going over a wake in a motor boat ,Im sure it was as intersting to watch from fellow drivers passing by.

A quick follow-up. Believe it is related to the motor mounts. Upon realllllly sloooow speeds, you can feel a twisting vibration, and it goes away as you accelerate or rev the engine. It also feels like the "wobble" is coming from the engine bay. In some respects, it almost feels like the car has Parkinson's disease, with its strange shake or wobble (not making light of Parkinson's---the car just "feels" like what I've seen from family members who suffer with such). Upon looking at the mounts, they appear to be flattened out. I'm only judging this by eye, and comparing that view to flattened mounts I've seen via photo in Google Search.

Didn't find any issues with tires or any suspension issues. Flex discs look very good (almost new looking!), plus the rear sway links look fairly new and were tight as well. Nothing noted from the tires, either.

I have new Lemforders, but they have the silly "open side" design. Whether to fill them with something in order to help them last longer or not will be something I discuss with my mechanic. Will keep folks updated when I get them done.

FINAL FOLLOW UP: See my post at the bottom of page 2 below. It appears to be solved after motor mount replacement with Lemforders, but more due to replacing the rack damper bolt and adjusting.

http://www.peachparts.com/shopforum/diesel-discussion/387854-engine-shaking-w123-om617-turbo-ideas-what-next-2.html