My truck shakes in overdrive and a lil in 3rd only at low rpm’s if anyone has any idea what could cause this plz let me know

 

Misfire? CEL on? Last time it had a tuneup? When I misplaced two plug wires on my truck doing a tuneup, it drove smooth (though down on power) until it shifted into O/D, then it felt like it was going to shake the truck apart...... Fix those wires, and it ran MUCH better/smoother.

 

Yep could very well be a misfire. I'd check pending codes even if no CEL

 

Could also be tranny mount or u joints, get a clunk when putting in gear?