What could cause this problem?

Question

I am borrowing a friends truck and when i accelerate to 60 miles an hour it starts to shake. What could cause this?

Answer 1

Hmmmmm maybe the fact that a redneck drives the truck....or maybe the person who you got it from "loves their horses" or maybe it just needs the tires to be balanced and the brakes are going bad. See i know this cause i be a Mechanic....

Answer 2

Wheel/Tire out of balance.  Can be exacerbated by worn out shocks.

Also, could be an out-of-round tire, often caused by tire damage.