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?

[Demick]

I've found my 914 to be very sensitive to front wheel balancing. Doesn't seem sensitive at all to the rear balancing.

For the front wheels, I've found it helpful to experiment with the position that the wheel is bolted on to with respect to the hub. Paint a mark on your front rotor by one of the studs, and mount the wheel so that the valve stem is lined up with that same stud. Drive the car - if you get the vibration, then remove the passenger side wheel and reinstall it in a different position (make a note of the position). Drive the car again and note if it is better or worse. Now change the position of the drivers side wheel. Keep rotating them around until the vibration is gone, and make a note of how the wheels are mounted so that you can remount them in the same position every time.

This has worked for me.

And like Josh said, tighten the wheels as much as possible off the ground. Rears can be torqued off the ground. Front's can't, but get them as tight as possible, and then torque them after you have lowered the car gingerly.

Demick