cupping tires

[blzrgb]

New shocks, recent alignment and balance, all new steering linkages, new wheel bearings and king pin bushings w/lower bearing, rotation every 3000 miles or less and i STILL end up with cupped tires !! (excessive wear on every other lug) This has happened on two different makes of tires (goodyear and mickey t) What else is there to do. I've even made sure the axle tube is straight. What the hell causes this ???

 

[Blood_of_Tyrants]

Is your avatar a pic of the vehicle with the problem? You might have too much tire or not enough suspension control.

 

[zout]

Great call Bloods - suspension control
The tire is getting allowed to "hop" and you would think your would shocks control this. IN a normal case - it would - but you are going outside the boundary.

There is another form of cupping and that comes from the build and mixing of the rubber in the manufacture stage. There was a specific tire mfg a few years ago notorious for cupping tires.

You can see your "footprint" from your pictures - you need to control that out of center footprint.

 

[paulfarber]

I would try harder springs.. maybe some rubber wedges to narrow it down first. Shocks only dampen the oscillations of the springs, changing the rate of the springs wold probably help.

Also try and up the air pressure. Firming up the tire with PSI may take some of the bounce out of the tire.

 

[Cucvnut]

plus the boggers you have in your avatar are a uber soft compound. there DOT certified but there wear on a road everdays makes there life very short.

 

[rlwm211]

Cupping is typically a worn suspension component issue. If your have replaced everything, this is not likely, however, you should check your wheel bearings and make sure they are properly adjusted.

When you lift and change the original suspension system it makes diagnosing a problem a specialist activity as opposed to looking for answers in "factory service" manuals.

Another factor is the large offset your rims have placing the center of the tire way outside of the spindle centerline. This aggravates any suspension issues. Additionally, it is possible your front axle is literally flexing under turns and adverse conditions.

I would assume you added drive line shims to your spring pads to change the pinion angle to accomodate the lift and this has changed the caster of the suspension and could likely be a cause of cupping as the amount of turn each tire makes in a turn is a compound measurement of both toe-in and caster and camber.

I would suggest finding a 4x4 shop that specializes in lifts and setting up steering and ask them for help.

 

[4bogginchevys]

Cupping is typically a worn suspension component issue. If your have replaced everything, this is not likely, however, you should check your wheel bearings and make sure they are properly adjusted.

When you lift and change the original suspension system it makes diagnosing a problem a specialist activity as opposed to looking for answers in "factory service" manuals.

Another factor is the large offset your rims have placing the center of the tire way outside of the spindle centerline. This aggravates any suspension issues. Additionally, it is possible your front axle is literally flexing under turns and adverse conditions.

I would assume you added drive line shims to your spring pads to change the pinion angle to accomodate the lift and this has changed the caster of the suspension and could likely be a cause of cupping as the amount of turn each tire makes in a turn is a compound measurement of both toe-in and caster and camber.

I would suggest finding a 4x4 shop that specializes in lifts and setting up steering and ask them for help.

It's definately the castor as pointed out. You shimmed for driveline angle and added nagative offset wheels that BOTH changed the "scrub radius". If you are serious about fixing it you can have an offroad specialty shop cut and turn the knuckles to reset the castor and point the pinion wherever you want.....just watchout for inadequate oiling in the front diff if you go a long way up with the pinion

 

[blzrgb]

Thanks Guys !

 

[rosco]

Another thing about "cupping", or excessive wear, is braking. Especially on cross lug tire pattern. Normal braking will wear the front part of the lug. When you look at the wear patterns, we usually look at the top of the tire, but the wear patter is backwards there, from where it is actually meeting the ground. When this patter starts, other wear traits can confuse it too.

Lee in Alaska

 

[paulfarber]

I don't think its anything unique to this setup. My front motorcycle tire cupped (quite common) as did the stock F150 I used to have.

Most tire shops tell you its the tire pressure. I've run my front motorcycle tire at MAX pressure (36PSI) and no cupping this year.

It could be the wired geometry you have, but its not unique to lifted vehicles.

 

[11Echo]

I don't think its anything unique to this setup. My front motorcycle tire cupped (quite common) as did the stock F150 I used to have.

Most tire shops tell you its the tire pressure. I've run my front motorcycle tire at MAX pressure (36PSI) and no cupping this year.

It could be the wired geometry you have, but its not unique to lifted vehicles.

I run 42,(maximum tire manufacturer suggested pressure), in the front tire on all my radial equipped bikes. I average 16-17,000 on them with even wear. Guys that run the bike recommended front tire pressures,(31-36), all have cupping problems. I adjust the rear tire pressure for loaded weight. I run more front pressure in my K-30's than the rear except when loaded real heavy also.