Straightline (Tracking) Stability
 

Symptom: Car ('92 300E w/ 185,000 mi) feels like its constantly driving through a stiff crosswind getting buffeting left and right. This happens above 40 mph. When passing trucks on the hwy, feels like I'm in a microcar.

Background: Front & rear shocks with strut mounts were replaced over the summer with Sachs. 4 wheel alignment done after left tie-end rod replaced with MB part. Three months later, symptom as described above was observed. Took the car for alignment at another shop that is an authorized Kleeman dealer. Aligned and reported that toe spec was off. Car tracked excellent. Now, two months later car has that "wandering" feeling again at hwy speeds.

What would cause alignment (done at reputable shops) of go out of spec twice within 2-3 months of the alignment? Should the initial replacement of only one (left) tie-end rod have been done as a pair? Thanks in advance for your words of wisdom.

Insufficiant trail and too much tow out.

Take it to Mercedes and let them align it.

Occasionally, will be delamination of the tyre/s.

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Did they check the rest of the steering/suspension when they did the left tie-rod? Is the suspension original? At that age and mileage a lot of stuff will probably be due for replacement, if it hasn't already been done so.

Also, if possible check the wheel bearings for wear, condition, and proper tightness.

i would suspect rear sway bar llinks.

also does it change direction on accel/decel? if so the small horizontal link rubber bushes on the right rear may be bad and nobody noticed it. (i can't imagine this, but you have had it worked on twice and still have a problem though). this link (i dont remember the name for it) can be observed by looking near the front of the right rear tire. the rubber bushes are plainly visible and are known to fail at fairly low miles on the 124 cars.

though the rear suspension is similar, the 123 cars did not have this component in them.

tom w

Steering & suspension components were supposed to have been checked at each alignment...I asked, they said ok. Wheel bearings checked out ok earlier in the year by the same shop that did the shocks and first alignment. They replaced just one ball bearing that looked bad (forget which side).

The car does not change direction on accel/decel like torque steer on a fwd system. Are these bushings you are referring to the same as subframe bushings?

http://catalog.eautopartscatalog.com/mercedesshop/sophio/wizard.jsp?partner=mercedesshop&clientid=catalog.mercedesshop&baseurl=http://catalog.peachparts.com/&cookieid=1W70PZW4N1YY0LCOH7&year=1992&make=MB&model=300-E-002&category=L&part=Thrust+Arm

http://catalog.eautopartscatalog.com/mercedesshop/sophio/wizard.jsp?partner=mercedesshop&clientid=catalog.mercedesshop&baseurl=http://catalog.peachparts.com/&cookieid=1W70PZW4N1YY0LCOH7&year=1992&make=MB&model=300-E-002&category=L&part=Thrust+Armer

Common fault on that type link suspension/chassis....new modified part is much beefier...

tires first. My toe was out and ate a set of tires in 17k. They were pulling by 5k. These cars will eat tires and if it was out of toe for even a few thousand miles, check teh tires before dumping money into anything else.