poor judgement... same thought i have... check and make sure your dog bones are not getting caught up in the diff cups... when they start to wear, the end of the dog bones bind in the diff cups... can be adjusted with the pillow balls and adding a o-ring to each diff cup.. mine used to do this and locked up the truck.. when I would pick up the truck, the bones would fall back into place.. I finally figured it out after bending or breaking many dogbones...