Front tires wearing in inside - why?

[SimpleXJ]

Hi guys, my front tires are wearing really fast, and on the inside edge. I have just replaced all the tie rods and tie rod ends, steering box and trac-bar. The rear tires are wearing fine. I rotated them up front and 2 months later I have major wear on the inside again, and they are cupping from the bouncing. I have 235-75-15's dunlop mud rovers on rusty's 3" lift. All this is on a 89 XJ.

I checked the ball joints (had a friend shake the tire as I looked for movement) - looks ok. Is there another procedure for checking ball joints? What could be the cause of this much tire wear?

Thanks all

 

[Blaine B.]

How's your alignment?

 

[lawsoncl]

Is the toe-in adjusted properly? If they are toed-in or toed-out a lot they will wear unevenly.

 

[RichP]

Check the ball joints this way
Jack the front end up about an inch off the ground, take a long steel bar and put it under the tire then pry up. If it moves your ball joints are worn. If you were local I'd show you on one of my TJ's, need to do them though they are not that bad and don't wear the tires.

 

[the_weirdo]

Check your toe-in/toe-out. In my experience too much toe-in will wear the outside of the tires; toe-out will wear the insides.

 

[SimpleXJ]

When I replaced the TRE's and steering box, I aligned it myself. I have done this before, so it's not new to me. I have the front set to 0 degrees. I do however drive on a lot of dirt roads with pot holes, so it could have gotten knocked off. I'll go check it again right now and post results.

RichP: so am I prying up on the tire and looking for upward movement at the balljoint fork?

Thanks all

 

[5-90]

Toe errors will cause "cupping" - which is distinctive (caused by tyre scrubbing.)

If you're just wearing out the inside or outside edge, but it's even, then it's a camber problem (caster doesn't usually cause tyre wear - just steering issues. Caster, on our vehicles, isn't adjustable and doesn't change much - unless you have other issues anyhow.)

"Camber" is the tilt of the tyre/wheel from vertical, and is usually measured at the top of the wheel. As I recall, "negative camber" means the tyre/wheel is tiled inwards overmuch (which will cause wear on the inside of the tyre,) while "positive camber" is the tyre/wheel being tilted outwards too much - which will accelerate wear on the outside of the tyre.

Have your alignment checked.

 

[cdryder43]

You need an alignment! Anytime you change your tierod, ends, trackbar, or any parts that position the axle, you should follow up with an alignment. It sounds to me that your toe is out. This could be caused by the trackbar not properly centering the axle and so pulling the draglink & tierod to one side or the other. It could also be that your tierod or ends are not set properly.

You can check it yourself with a measuring tape. Find a point on your tire tread that is uniform all the way around it and measure across to the opposite tire at the same point on the tread. Do this on both the front and rear of the tire. These measurements should be the same. Also, You can find a point on the framerails you can measure to at one point of both sides. You should be able to use the measurements (and I like to eye down each side and reassure my measurments) to tell whether or not your axle is centered properly. An off-center axle is a common problem with lifted XJ's. I recommend an adjustable trackbar and an alignment by a qualified technician on a modern alignment machine.

 

[SimpleXJ]

Well, I just re-checked the alignment. It was at 0 degrees toe. I adjusted it 1/8" toe-in (1 degree) just to be safe. I did the prybar trick RichP mentioned with a friend, and.... yeah there's play in the balljoints. When my friend pries up on the tire the balljoints on the drivers side move upward about 1/16". On the pass side they move about 1/8". That's bad balljoints, right? I found some on jcwhitney's site for $16.99 each. If this is a bad idea (buying them from JCW that is) please let me know. I'm kinda tight on cash right now but I need this fixed.

Thanks for the help

 

[cdryder43]

Toe errors will cause "cupping" - which is distinctive (caused by tyre scrubbing.)

If you're just wearing out the inside or outside edge, but it's even, then it's a camber problem (caster doesn't usually cause tyre wear - just steering issues. Caster, on our vehicles, isn't adjustable and doesn't change much - unless you have other issues anyhow.)

"Camber" is the tilt of the tyre/wheel from vertical, and is usually measured at the top of the wheel. As I recall, "negative camber" means the tyre/wheel is tiled inwards overmuch (which will cause wear on the inside of the tyre,) while "positive camber" is the tyre/wheel being tilted outwards too much - which will accelerate wear on the outside of the tyre.

Have your alignment checked.

Camber angle is built into a solid axle like the front of an XJ and is not adjustable. Tire wearing issues are ussually caused by toe in or out. Wearing & cupping on the inside is caused by toe-out.

 

[RichP]

I plan on ordering the ones from Summitracing, they have grease fittings on both the upper and lower ball joints, Moog, I figure about $200 for all 4.
http://store.summitracing.com/egnse...=700+400381+115&Nao=0&Ntk=KeywordSearch#rstop

 

[SimpleXJ]

I plan on ordering the ones from Summitracing, they have grease fittings on both the upper and lower ball joints, Moog, I figure about $200 for all 4.
http://store.summitracing.com/egnse...=700+400381+115&Nao=0&Ntk=KeywordSearch#rstop

I'm not sure you could ever get a grease gun on the lower one without pulling the axle shaft out of the way. The ones on my jeep now are not greaseable on the bottom, just on top. Clearance is really tight under the u-joint.

 

[WB9YZU]

I plan on ordering the ones from Summitracing, they have grease fittings on both the upper and lower ball joints, Moog, I figure about $200 for all 4.
http://store.summitracing.com/egnsearch.asp?Ntt=jeep+wrangler&N=700+400381+115&Nao=0&Ntk=KeywordSearch#rstop

Bad news Rich. The lowers you can't install with the zerks attached
You press'm in, attach the zerks, pump'm up, remove the zerks, and install the plug.
There just is no room for the zerks once the axle is installed and they will interfere with the axle.

You might just as well go down to your local autoparts store and get those same MOOG parts, for the same price, and save the shipping.

Ron

 

[5-90]

Camber angle is built into a solid axle like the front of an XJ and is not adjustable. Tire wearing issues are ussually caused by toe in or out. Wearing & cupping on the inside is caused by toe-out.

Bugger. I'm still finding out just how scrambled my brains got...

 

[RichP]

Bad news Rich. The lowers you can't install with the zerks attached
You press'm in, attach the zerks, pump'm up, remove the zerks, and install the plug.
There just is no room for the zerks once the axle is installed and they will interfere with the axle.

You might just as well go down to your local autoparts store and get those same MOOG parts, for the same price, and save the shipping.

Ron

Oh well, I've not really looked at the clearance and with the 8 inches of $$#$## SNOW we got yesterday and last nite I'm not going to.. Guess a 90deg is out too....