Tire wear problem plus a weird dealer recommendation (Ford truck)

My daily driver is a high mileage 1999 F-250 Super Duty. 400,000 miles.

Over the years I have had a pervasive tire wear problem which I can't diagnose.

It is currently wearing Cooper Discoverer ATR's. They are a 10 ply all terrain road tire designed as an original replacement tire.

The tires are LT235/85R16's with an "E" load range.

No matter what I do, I usually get about 20K miles out of the front tires. The rears wear evenly. The fronts do not.

But the wear is weird. Most wear patterns are viewed across the face of the tire. Center ridge wear, outer wear, cupping, second rib wear, one side wear, or feathering ALL imply something happening across the face of the tire.

In this case the wear is rotational. The tires wear "evenly" across the face (that is to say they have similar issues across the entire face), but each individual lug is wearing front to rear. That is to say, the leading edge (first to contact the road) of each individual lug is higher than the trailing edge, then the next lug is worn in a similar manner. There can be an 1/8" or more variation from the trailing edge of one lug to the leading edge of the next. The whole tire looks like the individual lugs are ground cockeyed, like an alligator skin.

Over the years, I've done the alignment, checked the front end components, bearings, brakes, shocks, everything (although not always at the same time). No matter what I do, the tire wear is similar.

I finally gave up on it, and resigned to replacing a pair of tires every 20K (and listening to the noise and vibration).

I don't usually deal with the dealership, but had a reason to be there recently.

The service department suggested it was not uncommon on these trucks, and that it was related to the alignment. He said that over time the alignment adjustment is limited, and there isn't enough adjustment any more. He said "fortunately the after market has a solution- after market adjustment cams", and said they could install them for something like $800- 1000.

While the price was steep enough, I was trying to figure out the diagnosis. Why would Ford have insufficient alignment adjustment for normal highway driving conditions? Why would they admit it? Why would they turn to the after market, instead of issuing a fix?

Any thoughts? I don't get Ford's perspective. Should I just resign to the fact that it is a high mileage truck and keep on replacing tires? What would cause wear patterns like this?

I know nothing about this problem...

But my BS meter is flying mad. Same brand tires? Sounds like weak tread block design.

Do you drive it in 4wd alot? Isn't there some minimal amount of "push" between the front wheels and teh back? If so, this could be the wear problem.

Just a total stab in the dark!

Sounds like the dealer is one turning to the aftermarket for a solution, not Ford. It sounds like the dealer is out to lunch to me. Did they say what parameter was out of alignment to cause this wear? Sounds like they have turned to the aftermarket to increase their profits. If it was a known Ford problem wouldn't there be at least a TSB out there for it?

If I had to guess, I would attribute it to the tire and try a different brand. Did the truck always do this or is a recent development?

Twin I-beams.... wild camber change through the travel. Common as the sun comes up everyday.

Normally, you can get around it with more negative camber with the aftermarket cams. Especially if it's wearing out the outer edge of the tire.

Brian

the googles tells me that the tread blocks wear like that from braking. How often do you rotate the tires?

I think this is called heel and toe wear and could be caused by incorrect caster.

I had a 97 F-150 which I lowered 2" in the front. The stock bolts did not have any cams for adjustment on them. The place where I bought the drop components and had them install them was aware of this. They included bolts with adjustment cams as part of the package.

IIRC, the bolts added ~$20 to the total cost and then I had the cost of an aligment to pay also.

Don't know if the 150's and the 250's had the same suspension but the dealer may be correct in saying that different bolts are needed. But the price they are giving you seems rather outrageous to me.

Ranger50 wrote: Twin I-beams.... wild camber change through the travel. Common as the sun comes up everyday. Normally, you can get around it with more negative camber with the aftermarket cams. Especially if it's wearing out the outer edge of the tire. Brian

Was twin I-beam still used in the SuperDuty?

Even if so, the description of the wear is not camber related - camber wear is excessive shoulder wear.

This sounds to me like running a aggressive off-road tire on pavement. The tread blocks soft and "fall over" as the truck sits on them, causing the leading or trailing edge to wear faster. I thought it was usually the leading edge that wore quicker, though... odd.

I'm going to second the rotate them more often opinion. If done in an X-pattern across the vehicle, that would change the leading and trailing edge of each tread block and they should average out to even wear.

Cupping is a common problem from lack of rotation, incorrect toe, and/or worn shocks.

Rotate every 5K to even the wear between front and rear tires.

i've seen what you're describing called cupping, caused by too much toe. as the tread block hits the pavement, the toe causes the block to flex as it passes through the arc where it meets the contact patch. as it begins to lift, there is less weight holding the tread block to the pavement, and it starts sliding more and more as it rolls off of that tread block. this gives the slanted shape on the treads, at least thats how i thought it out in my mind.

if your truck is a 4x4, it shouldn't be too hard to get the camber/toe correct, and caster is non-adjustable iirc. if you're 2wd, you might have the twin i-beam, which was non-adjustable for camber, and as the truck aged, the springs would sag, taking the camber out of adjustment as it does. not sure what the front end would be if its not twin i-beams, probably a beam axle similar to the 4x4 front suspension.

In reply to ReverendDexter:

Yes, still used.

I went back and reread the OP and I am wrong. I thought I read it as a camber problem and posted as such.

Brian

Wow- you guys are are quick! Let me try a few answers:

tuna55: What BS? The Dealer, the tire manufacturer, or me?

wvumtnbkr: No. It's a 2wd truck.

TJ: I stand corrected. Dealer, and you are probably right about him bumping up his profits. Truck always did it as long as I owned it (for the last 150,000 miles)

Ranger50: Yes twin I-beams, but no outer edge tire wear.

TJ: Brakes have been redone twice while I've owned it. I rotate the tires, but could be more diligent. In one post you said braking, tire rotation AND caster- which story are you sticking with??

Hal: F-150, and F-250 are very different animals (but similar designs- maybe similar problems). I agree, the price is stupid.

Reverend Dexter: Yes, twin I-beam in the Super Duty. I agree with your assessment about typical Camber wear (but TJ does not!). The ATR's are not an aggressive off-road. They are a multi-use factory replacement (primarily road, occasional off-road).

psychic mechanic: see above. I confess, but I haven't been that bad.

Cone_junky: This really doesn't look like cupping. Got it on the rotate.

Strizzo: I like your description. Sounds good...

Whew! Am I any closer to a solution???

does the truck see a lot of highway miles, or mostly around town? toe could be fine in a straight line, but the ackerman could be making strange things happen while turning. shot in the dark there though.

LOTS of highway miles. It averaged 60,000 miles per year for it's first 250K, and 30,000 since.

How many miles on the shocks?

Maybe 35K

I forget to ask what kind, too.

Just wondering if the shocks don't have proper valving to keep the tire planted on the ground and is allowing it to be springy and causing odd wear.

Factory replacement spec Monroes.

I suspected the shocks, but the wear is similar before and after replacement.

Rubber technologist's handbook

Look at page 371. There is an explanation of heel and tow wear and why it occurs on the non-driven wheels of a 2WD vehicle.

Not sure what the take away is as far as preventing it other than more frequent tire rotations. Have you tried altering the tire pressure?

Bad shocks tend leave larger flat spots. Toe and not rotating tend to screw with the individual tread blocks as described.

A friends F250 does the same thing. He never has been able to get it fixed. My E250 did this on the first set of Wranglers. I switched to a Uniroyal street tire and am now getting around 90K out of a set of tires. $1000 for a set of camber adjusters is out of this world unless he is doing the ball joints at the same time. The only other thing I can recommend is don't let just anyone align it. Find someone familiar with a twin I-beam front end. I've used the local Ford dealer for alignments for years now and don't have problems with front tire wear on any of my 5 Ford vans. They aren't as cheap as the local tire shop but I don't have to have them aligned as often either.

I stuck camber sleeves in an Excursion front end for a buddy for ~$100.00, check Rock Auto. That one was gobbling right front tires, the camber was way goofy on both sides, 1/2 positive on the left and 1 1/4 positive on the right. I went to something like 1/4 deg negative on both sides and so far so good.

Here's something to consider: do you haul loads with it constantly? If so, when it's aligned without a load the twin I beam is not set for the change brought about by lowering the back of the truck with weight. Also, as the front suspension drops (as the the front of the truck goes up) the TIB goes through some funky toe changes. So you might actually need to record your rear ride height when it's aligned, then if you carry a load set it back to that height (air lift bags or similar).

EDIT: Aggressive block pattern tread tires can also aggravate toe problems, the tread blocks 'twist' causing all sorts of wear weirdness. that could be why Toyman's gotten better mileage out of a 'rib' tread tire.

that's typical braking wear, and you can probably increase tire life by rotating with every oil change.