That happened to me a couple of times when I was driving FURD pickups with rusted-out front cab mounts. The weight of the cab puts a strain on the flex joint. Better check the steering shaft for alignment, and look at cab mounts in particular!
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!