Tire Wear

**SailorZ28** · 03-19-2006, 07:42 PM

bought a 99 Z28 recently, and it needs new tires. The car has a pretty bad vibration around 65mph, but below that and above that it's fine. The front tires have pretty bad cupping, what causes wear like that? I'd assume it's because of the front tires being so worn that I get the vibration, but what makes a tire wear that way?

The car only has 60k miles, never been wrecked, bought it off the original owner. It was a female too. So I doubt the car has been abused too much. Hell she knows more about cars than I do!

Thoughts?

**Bowtie Guy** · 03-19-2006, 09:34 PM

Wheel alignment, wheel out of balance, for starts.

**SailorZ28** · 03-20-2006, 08:20 AM

So probably a new set of tires with the usual mounting/balancing will take care of it then. That's about what I expected.

**The Old Man** · 03-20-2006, 05:55 PM

NOPE..... Gonna need new tires mounted and balanced... But at the very least youneed to get the front alignment checked also.. The cupping could be a bad shock also..

**Wayah-bird** · 03-20-2006, 06:50 PM

Definitely agree with the other posters. A wheel alignment is a must or you might ruin your NEW tires in no time at all.

**SailorZ28** · 03-20-2006, 07:31 PM

Well the car seems to drive straight, it just has that vibration and the cupping...

redls1bird · 03-20-2006, 08:04 PM

Originally Posted by SailorZ28

Well the car seems to drive straight, it just has that vibration and the cupping...

Ever heard: "Set the toe and let it go!"? its a common fraise in the automotive industry. with enough toe in i can make anything go straight. you have other factors in your alignment that could cause cupping. also, a lack of rotation on already cheap tires can cause cupping.

***Ed Blown Vert*** · 03-20-2006, 08:18 PM

Wheel Alignment

**SailorZ28** · 03-20-2006, 10:33 PM

Guess I'll have to get that done when I get tires then, hopefully in a few weeks.

Thanks!

adude · 03-20-2006, 11:46 PM

I'm shocked!! And you should be too, shocked that is. (as in you need new front shocks) 1999 you say, H'mm, I'll bet if you check them they will either be origionals or cheap leaking replacments. They only set you up to go downhill from there, tires, alignment, and so on. My suggestion is to check them first, and if you do need new ones do some research and get the best ones you can afford for the type of driving you will be doing the most of.

After you are satisfied you have no(or no more) shock issues, check the ball joints and alignment. With those issues out of the way your alignments and other front end parts will last much longer. With that, a good lube, and proper tire inflation you will probably be riding on Cloud Nine. On a 99 you might want to take a look at your suspention bushings, but with those miles, it's a toss up.

Good Luck,>>>Dan

**SailorZ28** · 03-22-2006, 06:25 PM

Crap I hope I don't have to do that kind of work to the car! I bought it thinking it'd be a pretty good worry free daily driver. I don't want to have to buy new shocks and bushings and God knows what else!

When you guys say I need an alignment, should I get the 4 wheel or just the 2 wheel? Roughly how much does that cost? And if I buy the tires at Costco, since they seem cheapest, do they do alignments there?

The shocks...well I'll worry about that if the car is still shaking after an alignment and tires.

**mrr23** · 03-22-2006, 06:31 PM

Originally Posted by redls1bird

Ever heard: "Set the toe and let it go!"? its a common fraise in the automotive industry. with enough toe in i can make anything go straight. you have other factors in your alignment that could cause cupping. also, a lack of rotation on already cheap tires can cause cupping.

really? yet toe doesn't cause a pull. i own an alignment/suspension shop. toe is the biggest killer of tires, yes. but doesn't create a pull.

cupping can be caused by a couple of things. improper alignment causing wear. improper balance, worn shocks are a few more.

**mrr23** · 03-22-2006, 06:33 PM

Originally Posted by SailorZ28

Crap I hope I don't have to do that kind of work to the car! I bought it thinking it'd be a pretty good worry free daily driver. I don't want to have to buy new shocks and bushings and God knows what else!

When you guys say I need an alignment, should I get the 4 wheel or just the 2 wheel? Roughly how much does that cost? And if I buy the tires at Costco, since they seem cheapest, do they do alignments there?

The shocks...well I'll worry about that if the car is still shaking after an alignment and tires.

it will only be a 2 wheel alignment, or what's called a thrust angle alignment. there are no factory adjustments in the rear. you reference off the rear axle to make the steering wheel straight.