I happen to notice when I am towing my 30ft. RV, I don't have any clunk at all in the rear end. I do have a little hesitation or wrap-up and clunk or catch when not towing starting off from a stop. My hitch weight is around 1k lbs. when towing and the truck is level with the weight dist. hitch. So, I started looking at the spring and axle configuration and saw that the bottom leaf at both ends only, where the pads are, has about 1/2"- to 3/4" space between it and the next leaf up when unloaded and not towing. When hitched up for towing there is no space between the springs at all. I noticed that there is no torque arms on the rear axle which mean that all the torque is taken up in the springs at each end where they attach to the frame. With the rear not loaded I put a wrench on the u-bolts that clamp the springs to axle and was able to put approx. 3/4- to one turn on most of the bolts. On a recent trip of 900 mile or so, I noticed that when not towing most of the clunk/wrap-up is gone except when accelerating rapidly. I plan to load the rear up with my trailer again and see if I can take up on the bolts any more without over torquing them. I would guess though, that it would be better to not have the space at the ends of the bottom spring which would not rely on the u-bolts to keep the axle housing from rotating. This I suspect is what lets the u-joints get over misaligned so that they are out of spec on the max. misalignment angles and causing a clunk or snap. I may cut some blocks of wood to fill the spaces on the springs and see if that completely eliminates the problem. I would like to hear if anyone else has tried this. TIA MR
- posted
19 years ago