Are rear bumpers adjustable (up and down)? My tailgate rests on the rear bumper when open, just enough to put a little pressure on the plastic trim. Don't want to take a chance of it cracking. The hinges seem to be ok and the cable on each side is not stretched, I checked against new ones.

 

Depending on the truck - but generally yes. Most will have sliding nuts inside the frame that moves. Put a jack under the bumper, loosen the bolts and lower the jack a bit. If it doesn't move on its own, tap it with a hammer.

 

I know this is way overdue but thanks for the reply. Yes the bumper is adjustable but the prev owner installed the hitch so high it prevents lowering the bumper, plus he welded the exhaust pipe hangers to the frame so they would have to be cut and rewelded. He apparentl gave no thought to how the tailgate would rest on the bumper.