odd vibration has me stumped
 

Ok maybe someone has some information that can help me narrow down this problem or maybe im not thinking of all the possibilities here:

1. I had a flat rear tire that I had repaired a while back. The tire was rebalanced and has since held air properly.

2. I started to notice a highway vibration or shudder about 2 months ago between 60-80 mph that would disappear outside of that mph range.

3. The vibration has no correlation with gear, throttle, or braking (if im doing 60-80 in even in neutral i can feel it)

4. I replaced my transmission a month or so ago with a 4.44 (which i love btw) and have done all preliminary maintenance (tranny filter, new diff fluid, lsd additive, etc)

5. I replaced my ball joints a week ago

6. After the transmission replacement I still have this mph related vibration that I cannot pinpoint.

Currently Im considering that I should have all wheels rotated and balanced and then the only thing I can think of is when I had my flat tire I bent the rim.

How likely is that? I have sti BBS wheels which are forged to my knowledge:confused:

Re: odd vibration has me stumped
 

You could have bent the rim, but I would expect you'd feel that at lower speeds. Try rotating the tires and see if the vibration moves- if it does, have them rebalanced. You might have thrown a light wheel weight (like a 5) that would become more pronounced the faster you go.

Re: odd vibration has me stumped
 

I remember issues with my rims a while back and having no centric hub rings at all. I'm guessing you have some but maybe when the tire was changed it could fallen off when replaced? Just a thought really... otherwise I would have someone balance that specific tire with one of those spiffy machines though the name of said machine tends to escape my mind at the moment, sorry.

Re: odd vibration has me stumped
 

Did you use any fix a flat?

Re: odd vibration has me stumped
 

actually i did use fix a flat:rolleyes:

Re: odd vibration has me stumped
 

is fix a flat impossible to balance out of a wheel??

Re: odd vibration has me stumped
 

"Well THERE is your problem!"
Unless your tire mechanic removes all of the fix a flat it will continue to cause weird vibrations.
The best solution is to remove the tire from the wheel, wipe everything out, and remount, reballance!

Re: odd vibration has me stumped
 

Whenever I fix a tire with fixaflat in it, I just clean it out anyway. I doubt it would be that.

Have you considered an out of balance rotor, maybe a bad axle? I've seen those both happen before.

Also, I'd have the other tires balanced as well, and rotate them like suggested and see if the problem moves.

Do you notice it coming from a certain corner or anything?

Re: odd vibration has me stumped
 

I slung the weights off of my cobalt ss tire the other day and I thought it was going to come apart over 40mph. Everything was fine until 40.

Re: odd vibration has me stumped
 

my money is on driveshaft u joints...although the vibration issue appeared after your tire extravaganza it can also be a coincidence...just a guess though