Toe killed tires again

[BigCars4Ever]

I had tires and an alignment about 12,000 miles ago and the tires are definitely worn on the inside edge down to the cord again. The toe is out so far I can see it. I have a suspicion on what is happening though. I used a local Goodyear garage to have the alignment done. I think the only way to get the alignment correct is to leave the car running during the entire process. If the car gets turned off then the rake can go up or down depending on temperature of the air in the bags and the ambient. I've also noticed that my car dumps air out of the system after about 45 seconds. I don't know why it just does. If the car stays running the ride computer will continue to keep the car at the correct operating rake. Any thoughts??

[FordNut]

Wrong.
Have it aligned to Carfixer's specs. They are still within the factory tolerance range, just at one end of the limits, so if a shop tells you they have to align to factory specs there you go...
It's more work because they will have to remove the ears from the adjusting bolts in order to get enough adjustment range.

[MMBLUE]

I say, definately. With the air out the rear and thus having a diiferent attitute for the front caster measurements, will through it of and wear the tires down a lot quicker.

[MMBLUE]

Wrong.
Have it aligned to Carfixer's specs. They are still within the factory tolerance range, just at one end of the limits, so if a shop tells you they have to align to factory specs there you go...
It's more work because they will have to remove the ears from the adjusting bolts in order to get enough adjustment range.
see my post,yes carfixers specs are good but if the ass end of the car is down it'll change the caster. You can't really argue that.

[Got_1]

caster doesn't wear tires

[FordNut]

The rear of the car doesn't squat when it isn't running. There are hundreds of us that have fixed the exact tire wear problem the OP described simply by getting Carfixer's alignment. Without the car running.

[Got_1]

^^^ if it does he's got an air suspension problem that should be addressed

[MMBLUE]

The rear of the car doesn't squat when it isn't running. There are hundreds of uw that have fixed the exact tire wear problem the OP described simply by getting Carfixer's alignment. Without the car running.

BC4E's car has eibachs and lowers the car to begin with. And when the ass end of the car is down YES it will throw off the caster and, yes caster (out of the limits) wears tires.

[Bluerauder]

see my post,yes carfixers specs are good but if the ass end of the car is down it'll change the caster. You can't really argue that.

I agree that the rake of the vehicle acts in the same direction as Caster but the overall impact is minimal. Toe and Camber will have much more impact on front tire wear and should not be impacted much at all by the small change in rake because they act in different planes than rake. Improper Toe will scuff the tires and increase wear. Improper Camber will cause the tires to wear on low side.

Linky here >>>> http://www.ozebiz.com.au/racetech/theory/align.html

Use carfixer's alignment specs and make sure that the shop is not substituting Grand Marquis specs.

I have nearly 7 years and 70,000 miles on my MM and have never had an alignment done at all. Tires wear evenly across the front tread and I am getting 34,000 - 36,000 miles on the OEM BFG's. No inner wear at all.

If your Toe is out that bad visibly, I suspect that the alignment was not done properly. Alternatively, you may have hit a pothole, curb or something to knock it out of alignment.

JMHO.

Here is the link to Carfixer's Alignment Specs .... the first one is the most current >>>>> http://www.mercurymarauder.net/forums/showthread.php?t=53921&highlight=camber

CARFIXER'S ALIGNMENT SPECS

For best tire wear, here is what I use on all MM alignments:
Camber: -.3 to -.5 degrees (was 0 to -0.3 degrees previously).
Toe: Zero degrees.
Caster: 5-6.5 degrees positive with .3 degree lead on the right side.

[FordNut]

The rear of the car is only down if it has been adjusted to be down. It does not squat when the car is not running. Unless something is broken. Leaving the car running during alignment will make NO DIFFERENCE.

[Got_1]

Caster will ONLY do the following... cause a pull to left or right, make steering difficult or easy

Camber and Toe are wearing angles

[MMBLUE]

Caster will ONLY do the following... cause a pull to left or right, make steering difficult or easy

Camber and Toe are wearing angles

What is camber?

Camber (http://www.goodyear.com/cgi-bin/gov/govcat.pl?to=camber) is a measure of the tilt of the top of a wheel inward or toward the vehicle or outward and away. Negative camber is the tilt of the top of a wheel inward toward the vehicle. Too much negative camber causes accelerated wear on the inside edge of the tire. Positive camber is the reverse -- the tilt of the wheel outward or away from the vehicle. Too much positive camber causes accelerated wear on the outside edge of the tire.
Linky
http://www.policedriving.com/article76.htm

[Got_1]

thank you for verifying what i just said

[MMBLUE]

thank you for verifying what i just said

Your welcome, now Caster.

What is caster?

This is the forward (negative) or rearward (positive) tilt of the spindle steering axis on a car or the kingpin on a truck. Correct caster on a vehicle is never perfectly vertical but is always set on a slight angle. A bicycle provides a good example of caster. The front fork on which the front wheel is mounted is almost always tilted back, giving the front wheel positive caster.
The basic purpose of caster is to maintain directional control, give more on-center "feel" to steering, and return the vehicle to a straight ahead position when exiting a turn. Insufficient caster causes wander, road shock, and a light feeling in the steering. Excessive positive caster can cause hard steering, shimmy, and tire wear in extreme cases. Unequal caster causes the vehicle to pull or lead toward the side having the least positive caster.
When caster is out of manufacturer's specification range, tire wear may occur as a result of incorrect camber on turns. However, loose or worn steering or suspension parts that would produce an incorrect caster angle would also affect camber and toe, which would also cause tire wear.

[FordNut]

If the car gets turned off then the rake can go up or down depending on temperature of the air in the bags and the ambient. I've also noticed that my car dumps air out of the system after about 45 seconds. I don't know why it just does.

The height of the rear end adjusts based on the position of the sensor. If ambient or internal air bag temperature difference is enough to change the position outside limits determined by the sensor, it will let some air out if it is too high. If the key is on, it will turn on the compressor and add air if the rear is too low.

The car probably lets a little air out because you got out of the car, not because you turned it off. When you get out, there is less weight in the car so the rear raises a little bit. Safety interlock prevents the car from letting air out while the door is open, that way the bottom of the door doesn't get hung on a curb (or smash a foot or head or whatever). When you close the door, the air suspension then lets some air out.

Try it. Turn off the car and stay in it. Sit there a little while and see if it adjusts the rear suspension.

You can actually measure the difference by having somebody turn off the air suspension while you're sitting in the car and measuring the distance from the ground to the fenderwell lip. Then get out and measure again. It's probably 1/4" or maybe even 3/8" difference.

[Got_1]

Caster would have to be WAY out to have any "noticeable" wear from incorrect camber on turns...also called tire scrub radius.

i do alignments all day at the Ford dealership i work at.

the original point was that if the rear of the car was lower it would throw out the caster angle enough to wear tires and that will not happen unless the ass of the car is sitting on the bump stops

[bobsawyer7]

The rear of the car doesn't squat when it isn't running. There are hundreds of us that have fixed the exact tire wear problem the OP described simply by getting Carfixer's alignment. Without the car running.

:bows:Carfixer specs solved the problem on my '03

[BigCars4Ever]

Wrong.
Have it aligned to Carfixer's specs. They are still within the factory tolerance range, just at one end of the limits, so if a shop tells you they have to align to factory specs there you go...
It's more work because they will have to remove the ears from the adjusting bolts in order to get enough adjustment range.

Not only do I have it set to carfixers' specs but I have removed the ears and elongated the slots in the frame. That's why I think something else is going on.

[FordNut]

Maybe the fact it is lowered puts the suspension geometry in a place where the camber is causing excessive wear. Pull the lower control arms in a little bit more.

[BigCars4Ever]

That's why I slotted the frame so I could max out the adjustment and pull the arms in as far as possible. I think the shop just screwed it up. I made an appointment for Monday at Central Florida Lincoln Mercury. The tech there is really good. He's the one who suggested making the slotts longer. I got two new Kuhmo Estcas so we'll see how this goes.

[babbage]

Flip switch in trunk to off after car is "level" then they won't release.

[BigCars4Ever]

Well I watched my car go on and off the alignment rack 3 times. While it doesn't pull over uneven pavement anymore it still "looks" like the toe is out. I'm going to borrow some levels and check it myself like MMBlue suggested. I can't afford to keep putting tires on this car.

[Bluerauder]

Well I watched my car go on and off the alignment rack 3 times. While it doesn't pull over uneven pavement anymore it still "looks" like the toe is out. I'm going to borrow some levels and check it myself like MMBlue suggested. I can't afford to keep putting tires on this car.

To be honest, mine gives the visual impression that the front wheels/tires are pointed outward by 1-2 degrees. However, the car tracks true and the steering wheel remains straight at highway speeds even if I take my hands off it. No edge wear at all. Maybe it is just an optical illusion because the front fascia does not line up with the edge of the tire giving the impression of a "toe out" condition. :dunno: Like I said -- I got 36K on my 1st set and 34K on my 2nd set (probably had 2K left in those but decided it was time to let 'em go). I have been running the BFG OEM 235/50/18 since I bought the car new in October 2003. Never had an alignment either.

[Stranger in the Black Sedan]

I am aligning my own cars at home, finally shelled out for enough tools to do it, and I played with vehicle rake vs. caster measurements on the Marauder. A 1.2" change in rear ride height affected the caster reading by 0.4 degrees, equally on both front right and left as you'd expect. The lower the rear ride height, the lower the caster and vice-versa. However the caster will be effected equally on both sides as the rear ride height changes, so this will not cause a tire wear issue. If your car reads +5.5 caster left and right or +6.0 caster left and right, it will change how aggressively the return to center feel is, and it will change camber during the turn, but that small of a caster change caused by a small rear ride height deviation, shouldn't be the problem.

And yes the shape of the front bumper makes the wheels look toed out when they are not.

If you are getting iner edge wear you either have too much toe out, too much negative camber, or both. The fastest way to wear inner tire edges is to have a combination of too much toe out AND too much negative camber. That is how our cars came stock.

[LeoVampire]

Well I watched my car go on and off the alignment rack 3 times. While it doesn't pull over uneven pavement anymore it still "looks" like the toe is out. I'm going to borrow some levels and check it myself like MMBlue suggested. I can't afford to keep putting tires on this car.

Toe or Camber?

Lowering or raising the hight of the car will effect Camber not the toe.
Toe being off for a long enough amount of time will usualy cause a feathering effect accross the tread of the tire and usualy wears the tire out accross the face of it.

But Camber will wear the outer or inner edge of the tire without having much of an effect on the rest of the tread area.

When you guys post these questions you need to take some pics of the tires to post the wear paterns and how it looks on the car sitting wise.