I just had my truck checked out at the dealer for a rattle in the engine. The truck runs just as it always has no performance problems. It has 117000 miles & I am the only owner. I always change the oil every 3000 miles.They are telling me I need a new engine I first noticed the rattle after I had the rear seals replaced. Only heard the rattle when the starter first kicked from the rear of the engine. Recently from the rear of the engine I could hear a slight rattle during acceleration after starting (like a jar of marbles bouncing around inside). It has become louder but still happens starting the truck & only when accelerating.
If this helps this is how the mechanic listed the cause on the work sheet:
Rod Loose Knob crank Low end rattle rear engine
Thanks, Gary