Tire Cupping

[shooked]

I have a 98 EB AWD with horrible tire cupping on the inside of all 4 tires. Wear across the rest of the tire is normal. I cross rotate as per my tire dealer and still didnt help. Ive had the alignment checked 2x, and within spec. I plan on replacing the shocks (see other thread) soon. Whats got me is it is all 4 tires, the left driver has it a bit worse than the other 3. I have seen the TSB for a modified alignment for the sport trac, does anyone know of the same for the Ex? Anyone else with AWD and similar issues?

 

[SnTx4]

My fronts wear on the outside edge, always.( 98 Awd) I do know once a tire starts a wear pattern it will continue to wear that way. So if your fronts are wearing, even if rotated to the rear its still going to continue. I think the Awd are just harder on front tires. But cupping alone is usually suspension related, worn shocks. Or tires out of balance.

 

[my98nnj]

Check the ball joints, my 98 took a perfect alignment with completely toasted lower ball joints. Driving on them was playing havoc on truck. Figured it out after I realized how to check the b.j. for play.

The alignment while the truck was sitting stationary on the alignment rack was perfect, but once the truck was moving the worn out ball joints allow the tire to squirm all over the road causing the tire cupping issue.

 

[shooked]

Turns out to be the upper ball joints. The tops of tires were splayed in and bottoms outward making it look like camber was off, sort of like a low rider. Lowers were not too bad, but replaced them as well. Popped right out and news in with impact gun and Snap-On ball joint press.

Drivers side control arm on top was a bear to get rear bolt out, with the 3 lines in the way to get bolt past. Different ride now. Thanks guys!