02 FX4 Supercab 5.4. 6" Fabtech on 35" BFG A/T's on 16.5x12 wheels with 51mm off set. Truck has the "death wobble" between 40-50 mph. Friend says it could possibly be the idler arm. Not too sure. Just had the tires and wheels mounted and balanced today. I didnt have this problem running my 17x8 Pro Comp alloys and 35" Mickey Thompsons. Any advice would be greatly appreciated.

 

my dads truck did that, but his rims were out of round

 

Recommend having them recheck the balance on the new tires. I have had occasional problems with them not being done correctly resulting in a significant wobble.

 

I agree with Wink...get your tires rebalanced, and if the problem persists then you know it's one of your steering components (tierods, pitman arm, idler arm, wheel bearings, etc.)

 

Get your wheels rebalanced. Same thing happend to me when I first got my new rims put on.

 

Bent rim, tire out of round, tire out of balance. Pretty much it unless your front end steering goodies are toasted. Even then, won't cause that much of what you're experiencing.