The rear control arms bushings slipped out of the retainer on the rear axle. I had the u-bolts very tight but not tight enough (I guess). I rebuild the rear suspension with IPD polyurethane bushings the rear axle painted with por-15 had the u-bolts tight. The 544 ran nice put about 500 miles on the rebuild dumped the cluch (hole shot) and a big thump noise from the rear end. The control arms at the axle spread out and jump over the bushing guides on the axle which caused the axle to move forward. Actualy shorting the wheel base a bit and bound up the drive shaft. The por-15 paint and the ploy bushings are very slick and the bushing guides are not very tall. How tight can you tighten the u-bolts? I will put her up an the lift tommorow hope not any unseen damage.