tire wear, specifically front

Jack_Berry

Moderator Emeritus
does the outside tread wear more than the middle?

reason i ask is the fronts on the truck I will be driving has higher tread in the center by about 1/3. the former fronts were cupped and an alignment was to be done and shocks installed. i knew i was getting used fronts but wonder about the difference in tread. tomorrow i will get a guage and measure the depth across the tire.




Jack Berry
 

ATeam

Senior Member
Retired Expediter
There is a lot to know about truck tires and tread wear patterns, and I'm no expert. Not so long ago, I would have said the same thing Greg said about your tires, underinflation. On car tires it would be a good bet, but on truck tires, it may or may not be. That is because truck tires are designed differently and behave differently under varying conditions. Car tires are less subject to such variables.

For example, on one truck, it may make perfect sense to run the steer tires at the inflation printed on the side of the tire, say 110 lbs. On another truck, with the same steer tires on it, it may be better to run at 80 p.s.i. Differences may include load characteristics (weight on the steer tires), the speed at which the driver normally operates over the road, the wheel cut built into the truck (how sharp the front wheels will turn), and more.

As I continue to study truck tire characteristics, I am learning that OVERINFLATION may cause the problem you describe. To confuse things further, if you use the number printed on the side of the tire to determine your proper inflation level, a steer tire inflated to 110 p.s.i may seem to be properly inflated. But a look at your particular tire's load table may reveal that 90 p.s.i. is best for the load your steer tires generally carry. Further research may indicate that an entirely different tire may be better suited for you.

If your steer tires are designed for heavy loads and you are running them at maximum pressure, but if you are carrying lighter loads than the tire was designed for, you will not have an even footprint across the surface of the tire as it contacts the road. The center ribs (treads) will contact the road well but the outside ribs will not. This may produce the irregular wear pattern you describe.

As Goodyear puts it,

"If a tire is highly loaded, it tends
to have a square footprint shape. The
shoulder rib contact area is very long,
about the same length as the center ribs.
As the tire rotates, contact with the road
is good.

"By contrast, a lightly loaded tire tends
to have very short shoulder ribs, much
shorter than the center rib. As this tire
rotates, the footprint center maintains
very good contact but the shoulder
area does not. This causes much more
scrubbing action and wearing away of
the shoulder rib."

Some of this is counter-intuitive but it makes sense as you think about it. It takes a little work to get familiar with terms like shoulder ribs, crown, sidewall, etc. But the work is worth the effort if you want to "dial in" your tires to your particular truck and the way you drive it.

A helpful publication is free online at:

http://www.goodyear.com/truck/pdf/radialretserv/Retread_All_V.pdf
 

unorthodoxneon

Expert Expediter
I was told by a few tire people that straight trucks are harsh on steers. Mainly because they are not really ment for the work that they do. They are under alot more of a weight load then they would on a semi. This causes the tires to wear funny.
 

theoldprof

Veteran Expediter
The front tires on my GMC van were cupping badly on both insides. Took it to a REAL alignment guy who said when I replaced the tires to bring it in with fresh skins and he could take care of it. At about 95,000 miles I put the spare down and bought three new boots. The alignment shop was closed for some reason and I didn't get the front end aligned with the new tires. I traded the van off at about 200,000 miles when I retired. The fronts were wearing properly. The only thing I could figure was the Detroit roads bent whatever back into alignment and caused the tires to wear evenly. Who'd a thunk?

:+ :+
 

arkjarhead

Veteran Expediter
Randy,
That may be sure, but 12,000 the max for both t/t and straight truck? I found that alot of weight on the steers comes from fuel. It weighs 8 lbs a gallon. So if you have a load and are close to being over on the steers, and have 1/2 tanks of fuel do the math to figure out how much more you can take on before going over. That 8 lb thing is a nice tidbit of info to have at times.
 

Broompilot

Veteran Expediter
These two items and one suggestion will add up to 50% longer tire life.

Centramatics $200. Steers installed at Petro and other Truck Stops

Correct Tire pressure.

Your responsible for front end alignment, one should be able to detect pulling or uneven tire wear. It should be done every PTI and everytime entering the truck between stops. Late afternoon or early morning using the sun and shodows will aid you in finding problems. USE your hands as well rub those tires, and when it has rained and you stop, they are generally clean and smooth to use ones hands in checking tires dry in about 3-5 minutes after you stop.
 

Jack_Berry

Moderator Emeritus
yeh, the truck i was supposed to be in needed shocks and a kingpin. fl told me that the kp should be done in pairs. just as well it didn't happen.

took the wife for a ride in a repoed fld ex w/g today. there was a 4 rib bs on the right and a 7 rib gy on the left. thought i saw unusual wear on the left tire. drove the truck and the wheel was never centered. okay 1500 bucks right there. she was amazed at the size and noise of the truck compared to the m2 i was supposed to be in.


how you doin with the new company robsdad?

Jack Berry
 
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