I recently had a lowering job done on my 2002 150 Super crew. I had a 2" belltech kit put on the front and a 4" DMJ shackel kit put on the rear. I also bought new tires and wheels. 20" lightning look-a-likes, and Goodyear Eagle II 275/45/20. The truck looks great, but, When I get upto about 65 miles per hour the truck shakes. I have had the front end aligned and the wheels balanced. Could this shaking be from the drive shaft angle being changed??? I am beginning to think the wheels maybe bad. Also does anyone know what changes Ford makes to the Harley in terms of suspension or drive shaft. Thanks for any help.

 

If I had to guess, which I am, Id say it is the drive shaft angle. You probably need shims that go between the leaf spring and axle. The wheels may be out of round, but I'd look into the shims first.

 

what shakes. the front end. or a nibble in the steering wheel. or in the seat of your pants. like rear end. and does it change if you let off the gas and coast down through that 65mph range. or is it worse faster you go over 65.

 

I dropped my expo on a 3/3 belltech kit, springs in front and re-position rear airbag sensor in back. Anyways, it shakes a little bit, not really in your seat as much as the side view mirrors a little bit, nobody notices it but me, but I thought the same thing when i first noticed it (driveshaft that is)

 

I think I might have the vibration problem solved. I talked to another mechanic and explained to him the problems. He did mention the shems in the rear springs, but said to try Butler Tire company in Atlanta. They do a on the vehicle high speed balance. I just got back from the shop. The vehicle rides smooth now. The technican said the tires needed to be indexed to the wheels and that the computer balance machines do a pretty good job but nothing beats a on the vehicle high speed balance because you balance the axels, the rotors, and the tires and wheels. What he said made sence (at least to me it did). The truck rides smooth now. The only draw back is the price. It cost $40.00 per tire for this service. Thanks for all the ideas. This is a great site. Thanks guys!!