Simple fix for wobbly steering

[Morris Minor]

Wifey's beloved Merc CLK 350 cabrio (40k miles) developed a horrible steering wobble every time the car crossed a ridge between lanes, went over a pothole or manhole cover etc. I was convinced it was worn bushings or an alignment problem. We pointed it out as an item to look at during a routine service. Mercedes could find nothing wrong - but noted in their write-up that the front tires needed replacement (which I knew - but was in denial about - trying to be careful with the $$). So we had this done at the local tire shop.

Bingo. Problem fixed. It was the crappy 5-year-old OEM Continental tires that had made the car feel like someone had gone underneath with a wrench and loosened a few tie rods. Lesson learned.

[AutobahnSHO]

i buy only crappy cheap tires, and as such they are harder rubber so they last longer (poorer grip) so I don't even realize how long I own them.

I've had pretty bad 25mph shimmying from time to time, new set of tires fixed it last time, but it's coming back- and tires are only a year old.

[2o6]

Cheap tires are usually cheap for a reason. Maybe a belt shifted.

[Rich]

How did it develop so fast though?

[MX793]

How did it develop so fast though?

Radial belts may have snapped or shifted due to hitting potholes.

[Rich]

Radial belts may have snapped or shifted due to hitting potholes.

Interesting.

[Morris Minor]

I was wrong.

The change of tires improved things, but the car is still tramlining. Was coming home yesterday, doing around 60, & my wife thought I was wobbling the steering wheel. I wasn't. The car was jinking along longitudinal wear lines on the pavement surface.

Dammit. Wondering if it could be the rear suspension? We've had the front checked out.

[MX793]

Might just be a function of the vehicle's track width or tire width and the shape of the road surface.  I notice a bit of tugging at the wheel on certain roads.  Never really noticed it until I put wider tires on the car (which altered the track width).

[Raza]

Could it be wheel weights? When my Jetta developed a shimmy, they tried to fix it with wheel weights and it definitely lessened the effect.

[Morris Minor]

I did some Googling, read the Tirerack.com article on tramlining, & came across a couple of forum posts from other M-B owners complaining about the same thing. None of them were about the CLK though, C209 or A209.

There is no play in the steering and nothing when I grab the wheels & try to wobble them, but I'd have to get the car on a lift with the weight off the suspension to be sure.

Anyway, a couple of places said though to check the tire inflation pressure, which I did. Both fronts wheels were 5lb over (33 instead of the recommended 28). So I reduced them to 29 (it was very warm in the garage).  I took it out for a drive on the stretch of road that gave the problem yesterday and, it may be the power of suggestion or seeing what I want to see, but I could not detect it tramlining. We'll see how it goes.