Steering wheel shakes violently on highway ramps or curves...
 

Hello all,

I have just rebuilt both of my guide rod bearings and got the alignment done. Now the whole front end shakes badly as I'm taking on a curve on the highways (same symptoms noted on the ramps as well) at any speed higher than 55MPH. The car is almost un-controllable - slowing down makes it go away. Again, this only happens when turing the steering wheel at speed, as little as changing lanes - going in a straight line is still bearable just as before.

Before attempting to rebuild the guide rods, the front left tire was well worn on the inner side due to bad toe, and somewhat out of balance; but I never had this problem before. Is there anything else I should check before getting new tires?

Please help!

Thanks in advance,
Frank.

Check steering damper for leaks. Disconnect one end and check if it offers any resistance to compression and expansion.

Duke

My VW used to do just that exact same thing...until I replaced the control arm bushings...couldn't even do an alignment prior to replacement because they were so worn, the alignment jig couldn't get the car to track properly!

Check yer balljoints...

It does appear that you have some "issues" on the front end, especially if the vehicle does not shake when travelling in a straight line at higher speeds.

Have a professional carefully prod the ball joints and control arm bushings looking for something that has excessive play. If it's shaking as you described, the problem should be obvious. Get this repaired prior to putting tires on it.

I don't think the steering damper is the problem...
 

Hi there,
I don't think the steering damper would be the cause of this problem, I took the one off my 300D 3 years ago and haven't had any problems with it removed. (I took it off due to a clearance problem with the engine conversion I performed on the car.) I think you have a problem with something like the steering idler arm bushings being worn out - it sounds like real bad case of the shimmies! Of course it could be anything worn in the front end - ball joints, tie rod ends, or whatever. I'm betting on idler arm bushings, they are also easy and cheap to replace. I replaced them on my car when I did the engine conversion, cost around $30 or so, as I recall. Of course you could also have a tire ready to blow...

Regards,
Richard Wooldridge
'82 300D/4.3L/T700R4 conversion
'79 450SL
'75 280C

If it were my car I would check the tie rods.

Haasman

Lower balljoints are less than 2 years old; steering damper is also new. The tierod ends do look old (with one or two are leaky) though. Any ideas how to check them? I have two sitting in my garage (one for each side) if I could isolate the culprit.

I had the car on the jack stands for a month while working on the brake support bushings. Could that stress the tierod ends to go bad?

Thanks,
Frank.

I would agree with Haasman. Tie rods. Just take a long bar and pry upwards on them putting pressure parrall to direction of stud (at tie rod end-the swivel end) If it moves up and down then it is time to replace them.

blown shocks... and wheel hop?

Steering vibration on 126 chassis
 

Are you referring to the brake force support bearings? The threaded rods attaching to a light alloy mounting assembly and then they are anchored to the lower control arms, correct? If this is the case then perhaps you’ll want to confirm the integrity off the rest of the front suspension system before viewing my suggestion below. Duble check your upper control arms, lower ball joints, tie-rod assemblies, drag link and the steering coupler.

If all of these items are within specification than I might suggest having you reexamine your brake force support bearing repair. Lower each one of the bearings from the chassis anchor points; remove the 10mm allen bolts (4) securing the covers; cut a length of 8mm fuel line to fit the inner circumference of the deepest recess; place the hose beneath the “new” funny rubber buffer you installed on the cover plate during the initial repair. Once the rubber hose is installed it will require a little more effort to reinstall the cover plate to the bearing housing because the hose takes up the excess free play. Once this is done your brake force support bearings vill be good n tite, yah! Za most common complaint zis repair addressed on z 126 chassis vuz “steering vibrations/shudder at highway speeds ven braking.” :cool:

Update!!!
 

Guys,

I noticed some play in the front driver's wheel (or more so than the passenger's side). Since I already have two tierod ends sitting on the garage's shelf, I installed them on the driver's side - now the vibrations are GONE!!!

I'm pretty slow, so I took me about 45" to get the job done (first timer). I had the car on ramps; count the number of threads on each end and installed new ones with the same count - both ends fitted in their sockets with ease.

I've ordered new tierod ends for the pass. side, and the idler arm rebuild kit. Hopefully I could get to them in the weekend.

Thanks all for your efforts. The wealth of information I obtained from reading the tech articles helped doing this a breeze :D

cheers,
Frank.