A have an 04 stx 2wd scab, at 60mph i'm getting a nasty drive line vibration, rotated tires still same. Anyone got an idea where to start, no u joint squeaks either

 

My dad had a 04 150 with the EXACT same problem. Same speed and everything. It ended up being the pinion in the rear end. Ford had to put 3 rear ends in that truck before he traded it for his 07.

 

You could try getting the driveshaft rebalanced. Around my area its pretty inexpensive like 40-50 bucks at a driveline shop. I don't think it could be the pinion angle on a stock truck.. Other than that I'm not sure, possibly something internal in the tranny or rear end?

 

75k out of warranty

 

Pat, I know a guy who has a home shop and he will regear it for you (if thats what is needed) for 3 bills, you supply the parts. Sounds like a good time to throw in some 4.10's or 4.30's and a truetrac.

B.T.W. since you have an stx, you have the smaller 8.8 axle with 31 splines, if you want to do just gears try this

http://nationaldrivetrain.com/shopsi...high_perf.html

http://nationaldrivetrain.com/shopsi.../mbk_ford.html

 

I would definitely check the balance on the driveshaft and you may also want to look at you u-joints. A balance should not costs you more than $30-50.00 and u-joints can be purchased at any parts store.