On my 89 runner i have a set of BF Goodrich All Terrain TA tires that have some significant cupping, as in, my truck shakes when driving. Feels like a rumble strip almost.
I recently had an alignment done and got new shocks.
Im asking because i recently had an incident where i slid off the highway into a pole in rainy conditions and i have a gut feeling the cupping played a role.
The tires came with the truck when i got it from the PO 2.5 years ago. The truck also sat for 8 months as I it was inherited to me before i got my license.

Ill try to snag a few pics.

 

You sure the tires are balanced? Is one of the rims bent?

 

Tires are balanced and rims are fine. I can see the cupping but it dosen't really show up in pics. I didn't have working shocks untill i got the alignment 3 weeks ago.