Wheel balancing, or is there a different cause? Options

[JohnB]

I've owned three 914's over the last 25 years and all have had the same issue. At some speed between 60 and 70 mph I get the kind of shake you'd get from an unbalanced wheel. Even after having the wheels balanced I always get it and I've had every kind of wheel and tire combination (steel and alloy wheels of every kind, Yoko's, Bridgestones, Michelins, and Vredestein tires, you name it.) I've talked to a few other owners and they report a similar thing.

Is it possible there's an unbalanced half shaft causing the problem or some other thing like an out of round wheel I haven't discovered? Why can't I get the tires to act balanced?

The easy fix so far is to either drive lots faster (IMG:style_emoticons/default/driving.gif) or lots slower (IMG:style_emoticons/default/dry.gif) but I'd rather not have the problem.

I've also had the alignment checked and at least on my current car all's well except the right wheel camber (or maybe they said caster). They can't get it into spec. The shock mount looks like it's all the way forward and maybe that's part of that problem.

ideas?

[1970 Neun vierzehn]

Years ago, there was a guy that I got to know from auto-x that managed/ran a very respected tire store in the area. Since he ran a Tiger, and I, a 914/4, we were hardly in the same class (IMG:style_emoticons/default/biggrin.gif) ! He maintained, and after experiencing the difference, I had to agree, that balancing the wheels after the tires had been mounted on the rims and AFTER the set was installed on the car, was critical. After his shop finished high speed balancing the tires on the 914, the high end smoothness and stability were much improved. (IMG:style_emoticons/default/thumb3d.gif) It was kinda scary, though, watching f & r tires spinning at high RPM as the car sat motionless. (IMG:style_emoticons/default/unsure.gif)

Unfortunately, that tire service regiment has subsequently elluded me, and I sometimes find myself at somewhere between 60-80, and depending on the road surface, with some annoying steering wheel vibration.