My 05 has a hop coming from the rear at 40 to 45 mph. I have re balanced and rotated the tires to eliminate that possablity. I suspect the drive shaft. Anyone had this problem or know about it?

there were early problems with the cross member having loose bolts. Check that and all mounting bolts on the drive line.

Axle hop has traditionally been attributed to spring wind-up in many cases. One correction for this was the staggered front to back mounting of the shocks. Also many higher powered cars and trucks had aftermarket traction bars installed to cure the problem. So it is possible one or both of your shocks in back is bad or failing. Look also for the spring hanger bolts to be sure all is tight and unbroken there.

Let us know when you solve the problem as to what you found to be the cause.

Red

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2005 Titan KC SE, Helwig, True-Track, ARE MX Canopy