Help!!

I have an '88 420 SEL. I've done everything to the car, but often pick-up too much road feels and slight vibration- most noticeable at highway speeds.

This car has its original 15" late 126 (flat surface) alloy wheels. I noticed one of the rear rims- one of the lug bolts does not go in quite as far as the others (maybe 1/4 inch or so. Changed the bolt and still the same, as re this hole.

Do these rims have a history of being ultra-sensitive to being out of round or even to the slightest imperfections? Any suggestions?
Thanks.

Robert -
You car is extremely sensitive to tires and wheels imperfection. Have your's check on a Hunter GSP9700 balancing machine for trueness and balance.

Thanks, Tommy.

I have made a note to locate a shop with the Hunter machine. I'm sure this is a common 126 problem, so I'll keep all posted as things develop.

You know, its wierd. Some days, I just hop in the car, and it has road feel that's smooth-as-butter. Other days, in 30 seconds I know it will be rougher. It's so wierd. And here's a car with new Bilstiens, new tie rods, new Contis, good alignment, and a solid suspension with good bushings. It's like a car that has different road manners, depending upon its daily mood.

Now, I know I'm being a perfectionist. But, as you SEL guys know, when the car feels good, its a nirvana experience. So you keep wanting to re-experience this feel.

I guess I'm looking for consistency in that feel.

I've come to the conclusion that these late (smooth surface) alloy wheels were just too ultra-sensitive for long-term purposes, and that as they age through extensive road experience, the inevitable imperfections just thow-off the car. The real solution would be to replace all the wheels with a different style - but I've spent a lot lately, and that will have to wait.

Thanks again.

Robert -

From your discription on how it would feel fine one day and bad the other, it sounds more like a tire problem than a wheel problem.

If your tires are slightly out of balance or out of round they will react similar to your discription. Even 0.25 oz off balance would make the car feels nervous and the steering shake.

Also parking your car with hot tires would induce flat spot that would fit your problem discription.

In any case the Hunter machine will tell you where the problem lays. Just make sure that you drive your car for at least 10 miles before having them checked - this is just an insurance that flat spot taken out of the equation.

Good luck.

Tommy:

Thanks again. I'm going to look for the Hunter at a shop nearby (Miami).

Meanwhile, I'm intrigued by your "hot spot/flat spot" comment. You know, it gets about 90 in the shade with extreme UV down here during the day. Contis are soft, so you might have something there. Yet, how do I avoid parking a car with hot tires?

If you have any suggestions, let me know. Could be tires-you're right!

Bob.

Could very well be the tires. My wifes 420 had a hop to it and found out I had a broken belt in the tire.