? Wobble, I'd list it if I knew what it was. Options

[nivekdodge]

I'm managing to get all the things I don't like handled and I'm quite happy with the car. I do still have a shake or shimmy but not a death wobble at 60mph. I've been searching for a good thread to follow rather than just throwing parts at it. The wheel shakes a little but also I seem to feel it in the seat. Still does it in neutral downhill.Seems to leave with a constant pressure as in a turn.

Wheels balanced, nothing out of ordinary.
New turbo tie rods...
Anyone document a chase?

Thanks Kevin

[L-Jet914]

Have you checked wheel bearing play? Lower ball joint play? Wheel/Tire assembly balance? A bent wheel can also cause a shimmy at freeway speeds. Flat spotted tires can do the same.

[Superhawk996]

50-60 mph is almost always wheel / tire related. There is math behind why this is so but I’ll spare you the details.

1st suspect is balance - even when a shop says they are balanced - that doesn’t mean balanced to zero, just to within what ever their machine defaults to - usually 1/4 oz. Quality of balance often varies pretty drastically the skill or care of the tech doing the work. Someone may have balanced them and said they were OK. I’d have someone else double check that.

2nd would be the wheels and mounting. Rear wheels on the 914 are not hub centric. This becomes a problem if lugs are not tightened carefully and really is not fully resolved without going to hub centric adapters.

3rd suspect is tire uniformity. Google it. Short version - tires are not perfectly round nor does the tire carcass have a uniform deflection as it rotates against the road. Uniformity varies enormously across various brands of tires as well as within a brand depending on the tire construction and often depending on which plant it was made in. See video which includes description of tire uniformity.

I’d first start by moving rear tires to the front while carefully mounting the rears carefully (cross torque, in multiple increments). Does that improve or degrade?

After that I’d have the wheels/tires measured for uniformity by a shop that has a road force balancer (preferably a Hunter). It will cost you. But if you have a uniformity issue - this is your best chance at compensating it.


https://www.youtube.com/watch?v=4OvcOX74wh0?si=AKL6EHHVCgqPbOnO

[ClayPerrine]

Flat spotted tires can do the same.

Been there, done that. I flatspotted the front tires on my six conversion on the tail of the dragon. Betty was following me in her car. She was laughing so hard, she almost drove off the road. I spent the whole 1100 miles driving home with the steering wheel shaking in my hands.

That sucked.

I agree with the test of swapping front to rear. If it gets better, have them all balanced by a high end shop. The tire monkeys at discount tire have probably never seen a lug-centric wheel in their lives, and will put too many uga duggas on the bolts, and not in a proper star pattern.

Improperly torqued wheels can cause vibration with lug-centric wheels.

[dtmehall]

question:

doesn't it depend on the type of the wheel as to how sensitive is the described inbalance?

[Cairo94507]

I completely agree with having a reputable shop, one that does high-end cars, do the balance. I had a slight shake in my steering wheel when I first started driving my car, after it had been aligned and all 4 wheels balanced by a shop in LA. I had the alignment re-done in Folsom and then had the tires balanced by Roger Krause Racing in Castro Valley. Nice and smooth now.

[rhodyguy]

Remove the center caps yourself prior to any wheel work. The hammer and screwdriver method is destructive.

[randyt914]

if the tire and rims are truly balanced (2nd opinion needed)then look at bearings and rotors

[StarBear]

Chased the same problem at the same speed for several years. Front bearings were the culprits. (IMG:style_emoticons/default/biggrin.gif)