Tire cupping on 91

[slsmith]

I've had my 91 EB 4WD for about year (140k) and am noticing cupping on the right front tire.
Bearings appear to be tight.
I see in other forums a lot of Radius Arm Bushing and Ball Joint replacement.
Where should I begin to look?

Thanks

 

[dsfii93sport]

Sorry to respond w/ a question but,, what is cupping?

 

[Alec]

http://www.tirerack.com/about/techcenter.html

 

[slsmith]

Cupping is uneven tire wear. Makes your tires into mudders.