Have this problem on one of my Sierras, I think the beam mounting bolts have been over-tightened by someone in the past and its broken the spot welds on the nuts so the bolts don't tighten

Anyone had this problem before, looks like I'm going to have to cut into the shell somewhere to fix it, the question is, is it easier to do this from inside the car or underneath it (I don't know where the bolts are located specifically), but its one of the long bolts (the main one that holds the beam on) and one of the small ones on the beam mounting plate that won't tighten. I'd rather know what to do first before I go attacking it with a grinder in the wrong place

 

There was a lad in our group had the same problem with the longer bolt, he had to cut a section out from under the back seat. The smaller bolt should be accessible through the drain hole?

 

I thought you could get to it with the back seat out. I can check mine at the weekend if you like.

 

Could you not clean up where the bolt goes in to the chassis and clean the bolt and give it a couple of spot welds there and then take a little off the tube that goes up to it to save having to chop the car about and strip it?

OR cut a slot in the end so that you can hold it to stop it moving?...even weld something on?

 

You need to go in from the top

There is a locating tube that protrudes from the bottom in order to locate the top of the bush into place

Make sure that once it's done you put plenty of that was oil stuff up there to prevent it from reoccurring as it's the bolt head rusting up rather than the nut causing the issue

 

The small ones for the plate you can get a spanner to through one of the side holes to hold the now unwelded nut