i've got a steering wheel vibration that comes and goes. the car is a
87 300D w/ 245,000 miles. i have new yokohama avs db tires that are wearing perfectly, so i know that my prevous alignment problems are gone. (but the car did this on the last set of tires, too). the most consistent cause seems to be outside temperature - when its sunny 90F+ after the car is all heated up (50 miles into a 200 mile trip from nashville-knoxville) the vibration will be there at its worst and I will see the steering wheel vibration (and also feel it/hear it towards front of car - nothing thru the seat). on the very same return trip, when its cooler outside 80F and the sun has gone down, the vibration is less, the road, the steering wheel does not visbily vibrate. some inconsistent patterns -
it seems to do it without regard to road surface, but older roads can be smoother.
- hard acceleration on a freeway seems smoother (e.g. after the car has been stopped to buy a Coke)
- sometimes a left or right curve can make it stop
- seems smoother at 60 mph than when faster (69-80)

I don't feel its the tires or wheels, nor does my mechanic. Different tires and wheels do the same thing. Tie rods, drag link, steering damper, all control arm/link bushings have been replaced within last year to cure other issues. Wheel bearings have never been replaced. Front left wheel bearing tightened twice (loose), right wheel bearing tightened once. If the car is jacked up and front tires pulled at 12/6 or 3/9 the wheels are tight (except when the bearings needed tightening).

is it sensisble to think the wheel bearings should be replaced? any ideas?

thanks,
Brian

Check your driveline.

I bought my "82 300TD with 254,000 miles from an older gentleman. Well maintained car except it had your similiar problem. My problem was a combination of the following:
1. Old tires with weak sidewalls,
2. Worn front wheel bearings,
3. Major problem: On the drive shaft, the rubber center bearing support and center bearing were shot. My support was torn - original part.

I completed corrective action on the 3 items above - resolved problem.

While you are looking underneath car, check your frt and rear drive flex coupling for tears/rips and rear drive axle boots.

Hope this helps!

To diagnos a previous problem, the center support mount, flex discs and axle shafts were inspected and verified as Okay by my mechanic and dealer shop foreman.

Brian

I hate vibrations. Once you move from tires and wheels there aren't much left. BTW what kind of wheels?

Various cars get vibrations that are generated by resonant components. BMW is famous for vibrations based upon weakness in the longitudinal stiffness of the lower control arm. many Volvos do the same. So does the 140 chassis. I have never seen that on a 124 chassis. BTW what kind of wheels?

I do have another hypothesis, but I gotta know about the wheels first.

__________________
Steve Brotherton
Continental Imports
Gainesville FL
Bosch Master, ASE Master, L1
33 years MB technician

Brian - after reading your post I have to say that I'm experiencing almost identical problems with my C280. Although they are different cars, your symptoms are virtually the same as mine. My C class is currently at the dealership being diagnosed. So far no luck, everything checks out... although they admit the vibration is there. Look up my post C280 Going off a cliff....

I'll be watching your progress!

Mark E.
Ft. Lauderdale

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Mark E.
Miami, FL
2 X 1997 C280

I've never deviated from factory 124 rims. The current ones are from an early 90's W124 (12 hole), the ones before that were original style.

I drove about 800 miles today, and have some new information. I hope this does not confuse the issue as I'm trying to think of anything that I notice...

1. there was noise. almost like a faint distant ambulance. there was no unusual feeling in the steering when hearing the noise. i could heard the noise going straight down the interstate off the jersey barrier (or without ). turning right (for curve) made the faint ambulance noise cycle more quickly, not louder. speed and road surface affected the noise. older road surfaces were quieter. i first noticed the noise a day or two ago going around right hand curves about 50 miles/hr. at 40-50 the noise is probably loudest heard. i did not really notice this before this set of tires, but the last set was very loud overall in all conditions (hard rubber michelin pilot)
2. there is an oily film around the center cap to the lug holes of the front left wheel. only present on this wheel
3. slowing down, or downhill w/out much load seems to make issue more noticable (first noticed this months ago, as did mechanic, but there was also a brake issue there and he did work with that - car warped two sets of rotors, he replaced rotors and left side calipers)
3. the harsher vibration did not occur today and it was hot, and I travelled the same part of I-40

Those are all of the symptons I can think of, I've ordered of how reproducable/noticable it is, starting highest first.

Thanks for everyone's help,

Brian

(edited to remove comment about tire wear)

Good deal on the rims. They still could be bent but its not likely the problem.

The noise you describe sounds like tires or wheel bearings. Wheel bearing noise usually can be changed by loading. Thus a quick turn one way will make the noise softer or go away and the other direction it won't or it can make it greater.

Aside from the noise the 124 body has a dependence on the shock that doesn't normally occur on MBs. Wear in the strut can effect Camber and looseness can allow Camber movement with loading changes. All of this is due to the fact that the extention strut (the part that goes up and down) is a structural member of the suspension. Other suspensions like 140, 126 have lower and UPPER control arms with two balljoints securing camber and caster. With 124/201 the strut (like a large radio antenna) pins the top.

__________________
Steve Brotherton
Continental Imports
Gainesville FL
Bosch Master, ASE Master, L1
33 years MB technician

Have your wheels been DYNAMICALLY balanced? This means weights inboard AND outboard on every wheel.

The most common thing I've seen is the fact that many tire stores will balance alloy wheels with weights being applied ONLY on the inboard lip of the wheels. They do this because people complain about their wheels being scratched.

If the weights are only used inboard, the wheel is statically balanced and will not hop up and down, but this aggrevates the DYNAMIC balance which causes the wheel to wobble. I have gotten so discouraged with the people at the tire stores that I bought my own used computer balancer. On MB wheels I either use the two piece MB weight on the outboard lip, or a tape weight just behind the web of the wheel where it is not seen, this gives an outboard plane in order to gain a dynamic balance. The newer balancers are actually set up to tell you how much tape weight and where to put it.

If I were you, I would go out and look at your wheels. If there are no weights on the outboard rim, I fully expect that this is the problem.

Good luck,

Steve,

The shocks were replaced with HD Bilsteins right before I bought the car, about 62000 miles ago. The right rear shock was not mounted properly (the lower bolt into the a-arm was in the plastic bottom cover). I reattached it when I got home from Utah (2000 miles). The last alignment mechanic noticed the above mentioned right rear shock was leaking slightly. Since I haven't noticed any problems from the rear, I've left alone.

Based on what I told my mechanic he thought it'd be wheel bearing also.

Larry,

My mechanic does dynamically balance the tires. All four. He uses a flat flange and a centering cone on an old '79 Hunter like the one you almost bought. He says nobody every comes back with problems. I've had the tires balanced "on the car" in the past and have had the same/similar type problem.

Brian

also, when there is a leak in the steering box, it deteriorates the rubber bushings that can also cause vibration due to worn out bushings...

the pump and gearbox were resealed, the pump still leaks a bit, the gear seems okay, and it doesn't seem lose against the bushings. steering on the car is tight, box adjusted to remove play.

Thanks,
Brian

Apart from the steering vibration, I'm curious why the wheel bearings needed to be tightened....the left one twice! Bearings don't wear....they're not consumable items .... not in the traditional sense. How are they working loose?

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95 E320 Cabriolet, 159K

I don't know why bearings get loose. Seems to me they should be replaced. My mechanic looks at them, if the grease and bearing look Okay, he tightens them. I asked my mechanic why they get loose, and he didn't have an answer.

Brian

How can you say that bearings don't wear? Of course they wear, if they are lubricated properly they wear very slowly, but they do wear. That's why they are tapered roller bearings, so that you can simply tighten them occasionally. I just tightened them on my 124 car at over 200,000 miles, so you don't have to do it very often.

Have a great day,

Wheel bearings are an integral part of the wheel assembly. Heat and dirt wear the bearing assembly. As well, you have weight and stress factors to consider. Simply stated, I would replace the front wheel bearing assemblies. You have nothing to lose. After you remove the old bearings, take a look at the bearing assembly. You may see the pits and flat spots on the race. Cleanliness is the key with bearing assemblies. Clean the spindle and rotor bearing areas. When you grease pack the bearings, make sure your hands are clean as well as the high temp grease. Remount and torque to 12 ft lbs or whatever the maintenance manual recommends. Don't forget your cotter keys. This has worked for me the last 30 yrs.

Hope this is helpful.