This happened to me several years back as well. I was offroading with my cousin when I still had my OME lift and I was too lazy to air down that day. We were playing in some rock gardens and big puddles, and were bouncing around pretty good. When I got back onto the road, I noticed that the steering did not want to return to center without me giving the steering wheel a good amount of input to get it there.

I took my 4Runner into my shop and they determined that I bent the steering rack. So they order a new one and install it, then call me to tell me that the steering resistance was still there and determined that I had bent the shaft as well. They were very cool and only charged me for the steering shaft (no charge on labor to remove everything again and realign it), but I was shocked that I was able to bend the steering shaft the way I did.

I believe the combination of the extremely stiff OME setup coupled with the fact that I didn't air down that day is what caused enough force to be transferred through the tires and suspension up into the steering rack and ultimately the steering shaft.

I've since swapped out my OME setup for Icon CO's with remote resi's, as I had thought the OME shocks road too stiff on road anyway, and the bent steering shaft was the final straw before making the move to CO's.