Old bias ply tires also develop flat spots from sitting unused for a long time. Until they warm up and work the kinks out, the truck will shake like it's got square wheels. Back in the dark ages we called it "Nylon Thump". I had a 1959 3800 dually with 18" bias ply tires that would rattle teeth for 10 miles before the tires warmed up and got round!
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
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