Have a stock 1992 C2 with 80K miles. Flywheel was upgraded at 30K miles. When I hit about 55-60MPH, the steering starts to vibrate and then settles down at higher speeds. Happens in either 3rd or 4th. RPMs are about 3000 +/-.

Could it just be tire balancing?

I thought I once read something about the DMF symptoms being related to certain RPMs.

Thoughts?

 

Dave,

That sounds like like tire balancing, which hits around 55-60 mph.

 

Dave,

I second Bill. More than once I've had vibration immediately after getting new front tires, with the vibration being remedied by a second balancing.

Also, you might want to check that your wheel locks are aligned per the owner's manual. I've read of people having vibration when they placed the wheel lock in the wrong position. Amazing, but true.

 

Just to add to Randall's comments: the locking nut goes on the stud marked in red. On my car, the marked stud is clearly visible on three wheels but barely visible on the fourth. You're supposed to mount the tire by positioning the tire valve relative to the red marked stud, and the positioning depends on the type of rims you have.

Also, my understanding is that with the newer style wheel locks it doesn't matter how the tire is mounted or which stud the wheel lock is installed on. This is b/c the newer style locks are the same weight as the other nuts. The old style locks use a key, whereas the newer style use a socket with an internal pattern that mates up with the wheel locks. Anyone have further info one this? I can't remember where I read or heard this.

drew
92 C2

 

Hey Drew,

>Also, my understanding is that with the newer style wheel locks it doesn't matter how the tire is mounted or which stud the wheel lock is installed on.

I think you're at least partially right. Here are the salient sections from the 964 and 993 owner's manuals:


964


993

(apologize if the image it too small on your screen .... but, I'm not motivated enough to enlarge and re-upload the pic.)

Observations:

-The 964 manual specifies that the wheel lock be placed on the colored stud, and nearest the wheel valve.

-The 993 manual does not specify where the wheel lock should go, but does specify that the colored stud is across from the valve.

(BTW, I checked PET, and by the 993, the keyless locks were being used.)

Finally, FWIW, the people I've read of that had vibration caused by mis-mounting the wheel were 993 owners. Suppose I just haven't heard from 964 owners who had this self-induced problem ...

 

Interestingly, the directions for installing the 'Cup' wheels call for installing the colored stud OPPOSITE the tire valve. I'm assuming the directions you posted were from the owners manual for your '91, which had the Design 90 wheels standard.

 

Thanks for all the good advice. I'm learning that with these P-cars, nothing is as simple as it appears, not even a wheel balancing. I hope my wrench also know these guidelines, as I hate to pick up the car and have them remount them.

 

Hi Drew,

Yes, the excerpt was from my '91 manual. So, I guess the wording was changed in the '92 manual, with the Cup wheels. And, changed again with the 993 and/or keyless wheel locks. Completely-non intuitive.