Tired of buying new tires

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Tired of buying new tires

June 15, 2005, 12:14:51 AM

Has Anyone had the dreaded grinding of the outside edge of your front tires?(especially the front passenger) I have taken the tire to many shops who say my allignment is fine. I would think if they saw anything that was lose worn or broken, they would jump at the chance for me to order something from them or charge me labor to fix, But everyone says I'm just fine

when I know I'm not becase my tires are just grinding away slowly. Could it be bad bushings, maybe broken/worn steering components/ bent tierod? I've looked and everything does "looks fine" as far as what I could see. Do I need to just buy caster/camber plates and start from scratch? PS: My tierod ends have been replaced and this has not helped. I am running stock tires and wheels (225/60/r15) and suspension. on an 88 xr-7

Re: Tired of buying new tires

Reply #1 – June 15, 2005, 03:06:44 AM

When I had 15" turbines on my tbird I had the exact same problem. I had the alignment checked and rechecked several times but no one one could stop the tire from wearing on the outside. Once I went to 17" wheels the problem was significantly reduced. In fact, the tires wear very evenly now. But it also depends on how how hard you tkae the turns. Just my .02 cents.

Re: Tired of buying new tires

Reply #2 – June 15, 2005, 07:29:28 AM

Yea had similar problems,but it took a few years to wear them out.
I'd say it's normal.

Re: Tired of buying new tires

Reply #3 – June 15, 2005, 05:55:47 PM

Hell my tires are wearing better from just going to 16's up from 14's. The body roll of your car is probably the factor hear.

Re: Tired of buying new tires

Reply #4 – June 15, 2005, 06:38:55 PM

ya gotta rotate them thar tires....reguarly.

id say its somewhat typical of these cars but id be willing to bet something funky is goin on. my first tbird did that. had a bent subframe though. my second tbird wore very evenly on the front. (wore abnormally quickly in the rear...hehe). it had new stock springs struts and some bushings as well as tierods and ends and ball joints. cant realy say about the current one. doesnt get driven enough...cars tight though and tires look good. there new though.

Re: Tired of buying new tires

Reply #5 – June 15, 2005, 08:03:04 PM

You can have the toe-in reduced or add some negative camber... The camber is easy to play with, just loosen the three nuts on the strut mount and shove them all the way in toward the engine(may have to drill the rivets the factory installed, also a good idea to mark the original position in case you want to move it back). This is a move I've seen recommended in the Stang rags to help with tire wear and improve handling.. It does help, I've done it on some Stangs but my Bird has been OK.

Re: Tired of buying new tires

Reply #6 – June 15, 2005, 11:28:15 PM

The problem is inherent to the Fox chassis. The front suspension does not have enough positive caster built into it and what happens is that when the wheels are turned the outside wheel actually "falls over" on itself and camber goes postive. The lower profile tires will lessen this effect somewhat as the sidewalls are generally stiffer and resist the exaggeration of the problem. On a "stock" set-up there is not much you can do other than rotate the tires frequently.

Dialing in some static negative camber can help the wearing of the outside of the tire a bit, but you have to be careful not to dial in too much and start wearing down the inside of the tire too prematurely.

The only real "fix" is to dial in more positive caster into the front suspension, which is only possible with caster/camber plates. Dial in as much as you can get. What this does is improve the camber loss in steer and thus reducing the inherent problem with the stock set-up. For most aggressively street-driven cars, the c/c plates dial in enough that you can possibly find a good compromise of camber/caster so that tire wear will be good and grip will be greatly improved as well.

I have a -load of positive caster dialed into the front suspension of my TBird with custom c/c plates. I have other plans for it and may dial it back somewhat, but in it's current set-up the camber gain ("good" gain as is negative camber on the outside wheel and postive on the inside) is very noticable. So much so that I am able to run minimal (-1/4*) static camber and still have no issues whatsoever with tire wear and grip is incredible. The bonus to running almost no static negatgive camber is that the tire contact patch while in a straight line is 100% (ideal for maximum braking) and the insides of the tires do not wear prematurely.
Like I said I may dial the positive caster back some in a future iteration as at low speeds the geometry is too aggressive. Parking the car you can feel the tires scrub a bit...kind of a pain. At high speeds though, the thing is planted. I still could keep that though and lose a bit of the "issues" at low speeds though.

ANYWAY...to answer your question, to really be able to adjust the suspension to help reduce the tire wear is going to require c/c plates and as much positive caster as they will allow with a "reasonable" amount of negative camber ( -1/2 to -3/4*) to avoid the excessive inner tire wear. As an addition, there is a point where you can get too much positive caster, but you'd have to actually try to get too much as most aftermarket c/c plates do not allow for going past that point normally.

Re: Tired of buying new tires

Reply #7 – June 16, 2005, 02:08:47 AM

Hey chuck nice post and nice info but did you mean to say caster instead of camber in this paragraph?

Quote

The only real "fix" is to dial in more positive caster into the front suspension, which is only possible with caster/camber plates. Dial in as much as you can get. What this does is improve the camber loss in steer and thus reducing the inherent problem with the stock set-up. For most aggressively street-driven cars, the c/c plates dial in enough that you can possibly find a good compromise of camber/caster so that tire wear will be good and grip will be greatly improved as well.

Re: Tired of buying new tires

Reply #8 – June 16, 2005, 07:35:06 AM

Thanks for the great explanation Chuck, I knew there had to be more it than just dialing in negative camber(But since I'm a straightliner, I never thought much about it). I did have a TC that had been hit in the left front, and it pinched the tires so badly they squealed on hard turns at low speeds(it drove OK). The alignment shop said it was fine, but I knew they were FOS.

Hell I think that is worth a sticky, anybody agree???

Re: Tired of buying new tires

Reply #9 – June 16, 2005, 02:14:50 PM

Definitely stickyworthy, and for what it's worth, just a coupla weeks ago, I moved mine in as far as they'd go, and my new tires on the front are looking better than the old ones...
That is some good info there.

Re: Tired of buying new tires

Reply #10 – July 02, 2005, 09:28:33 PM

when I go autocrossing thats what I do, I shove the camber in to the max to help with handling. And it works to, I noticed more even wear across the tread of my race tires.

Re: Tired of buying new tires

Reply #11 – July 14, 2005, 10:25:10 PM

I had my 84 T/C aligined after my bushing kit in stall and they even drilled that factory CC plate rivet and moved the top of the struts in alot I have much better tire wear and I love the taction.

Re: Tired of buying new tires

Reply #12 – August 29, 2005, 02:24:41 PM

Well guys I dont know if my alignment its ok because when I left off the steering wheel its goes to the right side but the tires are ok, I put the tires when the car had 86000 miles back in may 2002 and know its over 127,000 and the tires are like new and its my daily driver hahaha

Re: Tired of buying new tires

Reply #13 – September 06, 2005, 04:35:01 PM

I Think Are Car's Get Mad At Us . I Mean I Took My Car To 7 Diffrent Shop's When I Was A Commercial Manager For Autozone.to Find Out Why My Battery Kept Draining.2 Of These Shop's Were Battery Electric Shop's They All Ran Test And Nothing.if I Left My Red Top Optima Hooked Up For 8 Hrs Or More It Would Die. So I Opted To Leave My Car Over Night To Show The Shop Owner It Would Die.i Get There The Next Morning And Met The Owner Just As He Was Opening The Shop.he Goes Inside Get's My Key's And Start's My Car Right Up.he Said Bear I Think You'r Crazy. So I Get In And Drive To Work About 10 Ft Next Door.park It For The Day.lock It Up And Called Her Bitch For The Embarisment.8 Hr's Later I Get In And .......... Nothing The Battery Was Dead
I Now There Was A Reason I Named Her Christine.and This Is The End Result . Relocated To Trunk With Positve Kill Located In The pen 15pit. So You Tell Me.. These Car's Get Pms .or Something

Tired of buying new tires

Reply #14 – October 20, 2005, 04:23:30 PM

ive heard of this problem and read online to move loosen the strut mounts and shove the struts all the way inboard, i did this on my TC and the outside of my front tires are perfect.