I had bad wear on my stock tires even after an alignment.
They were done after 14000... Very bad on the inside edge.
I had it aligned it was susposed to be fixed.. got new tires..
after 5000 on the new tires they were wearing the inside again.
I asked them to crank the tbars some(not max) and drive it around then
check it again... It came out with the same camber (forget what it was)
ended up getting cam adj kit from specialty products.. 48$ a side
free install as part of alignment.
Havent had any problems since. (30000+ miles)
Rand

 

hes a crazy, GRUMPY old man :-D

 

If you reread my post, you will see that I was agreeing with John 100%. Cranking the T-bars makes the camber go more negative and you either correct it or live with the tire wear caused by that change.

 

and i agree with you both also... :)

 

I agree in theory but it didnt do anything to mine.. for some reason.
I do believe my t-bars sagged horridly after about 6 monthes .. the crank took it only SLIGHTLY higher than new (maybe 1/2" or so)

And I needed camber adjusters BEFORE the t-bar crank

Rand

 

sooo any part #'s yet theres to many diffrent options

 

It is also kinda hard to screw up a camber measurement when the computer does it for you. I have been a tech for years, I think I know what I am doing when it comes to something as simple as an alignment.

 

If the actual camber is negative 0.5, the tires will have a tendency to wear on the inside anyway. Negative camber results in more pressure on the inside of the tire but gives better handling characteristics.

When I cranked my t-bars the first time I just lifted it about 1 inch. The ride height was still within factory (new) specs. I had the alignment checked and the camber was right in the middle of the tolerances but the toe had to be adjusted. A couple years later I cranked the t-bar another 0.5 inch and the ride height was just slightly above the factory (new) specification. When I had the alignment checked they had to make some minor adjustments but that is not surprising considering it had been two years since my last alignment.

I now have over 39,000 miles on the original tires and at it has been around 35,000 miles since my first t-bar crank. The front tires may have a little more wear on the inside but it is not significant and you have to look very hard to see any difference. I do rotate my tires about every 7,000 to 10,000 miles.

 

.5 degrees of negative camber is so miniscule it doesn't really adversly affect tire wear. If it wear more than 1 degree, I might be concerned. But even at 1 degree negative, if you keep up on tire rotations it would be fine. Negative camber also better for higher speeds. Not just like at track speed, but highway speed as well. It gives better stability for cornering. Something that can benefit any truck.
The toe will naturally change with any change in ride height, just like camber. For primarily rear wheel drive vehicles, a slight toe in is called for. There is a natural tendency for the front tires to want to toe out on rear wheel drive cars/trucks. For front wheel drive, the tires have a slight toe-in. When going down the road, the tires are pulled in by the drive axles. This is caused by the small diameter drive shaft turning a larger wheel/tire package.

 

Not so. Front wheel drives run neutral or slightly toed OUT at rest. It has nothing to do with small driveshafts and bigger tires. It is to compensate for steering and suspension compliance. Front drive tires pulling forward tends to flex the suspension, steering and bushings toward a zero toe attitude.

On rear wheel drive vehicles, the drag of the front tires tends to push back on the suspension, flexing the front end components the other way to a near neutral attitude. That's why rear wheel drive vehicles are, in effect, "preloaded" with toe-in when at rest.

 

As usual, Bob is absolutely correct on this one.

As to the -.5 degree camber not causing wear on the tire, that is true as long as the vehicle is going in a straight line or close to it. However, when you turn, the tire on the inside of the turning radius rolls over a little creating more pressure on the inside of the tire and will in turn cause the inside of the tire to wear a little more. This should not be significant unless the driver likes to zoom around the corner causing the front tires to slide a little.

I try to set up my race car with enough caster to help compensate for the negative camber and tire roll over in the turns.

 

You caught me on a typo as far as FWD goes. The tires should be toed out when on the alignment rack.

 

You're probably right. 1/2 degree negative camber is too much. Those guys at Ford and all the people that set the specs for the alignment machines don't know what they are doing.

 

I detect some sarcasm there. I don't recall saying that -.5 degree camber is too much. In fact I like to see a little negative camber for improved handling. Most American street vehicle use to run positive camber but manufactures have learned more about camber and caster resulting in better handling vehicles.

My point about wear on the inside of the tire was a response to earlier posts that sited wear on the inside of the front tires because of a t-bar crank. This may well be true but the negative camber can also contribute to this type of wear. I am only stating facts, not making personal attacks.

 

That was the whole point of John's OP. Raising (or lowering) an SLA suspension to any great degree causes the camber to go more negative. If left uncorrected, it will cause increased wear to the inside edges of the tires.

 

Yes, and I am trying to say that even if it is corrected to the -.5 degree camber, you can still get slightly more wear on the inside edges of the front tires. That could vary from almost nothing to significant wear depending how fast the driver goes around corners. My tires are at the almost no wear on the inside edge but I have heard others say they had noticeable wear.

 

The -0.5 camber angle translates to a difference of 0.087" across a 10" wide tire tread.

Tan (0.5) * 10"=
0.0087 *10=
0.087"

87 thousandths of an inch difference from the inside shoulder to the outside.

 

Dumb question of the day: So why isn't the spec 0.0 degrees?

 

You know how it is with engineering, Colin - the practical application of science and the art of compromise. Handling vs tire wear vs directional stability vs a dozen other things.

 

Like I said, dumb question!

But does -0.5 actually help w/ handling at all? It sounds so slight that I would speculate no! Don't NASCAR and Indy guys run at like 2-5 off (+ or -)?! And conversely, if -0.5 is so small and contributes to wear so minimally, why not help handling more by making it more?!

My guess is they've thought that through and -0.5, while it sounds small, is somehow significant in improving handling in one way or another. Or maybe it just prevents the suspension from going out of spec in the + direction, which would cause some significant problem I'm unaware of.

 

I think maybe they would like to run more negative camber from a strictly handling point of view but that would affect tire wear. Hence the compromise. The camber spec is -0.5 +/- 0.7 so your actual range is anywhere from -1.2 ~ +0.2.

Street vehicles need to turn left and right and be stable in a straight line while delivering long tire wear. Guys that only turn left have special needs. Obviously, tire wear is important on a long distance race car but I'm sure that left turn handling is still the primary consideration.

 

Bringing up a 10 yr old thread with a question.

Has anybody found any camber bolt kits with more then 4.5* total to them?

With a 2" coil over (same as TT) lift, running new 35 MTr's, I have botomed out my +/-2* (4 degree total) cams and still have too much negative camber. If I could find a cam kit with greater then 5* total adjustment, I could open the bolt slot a bit with a die grinder and get more adjustment.

Thanks in advance!