YO!
e ok
in re; "well I checked the body mounts and"...did you pull da carpet or vinyl mat up around the area where da mounts are? figure on a horror picture type scene,,, guessin' (based on some shore-based & road salt attacked and destroyed Broncos I've seen - as in your case I believe) that there is absolutely nothing left of floor pan/support bracing area where da bolt head is .. sorry
GL!
EDIT; found following by Steve;
"It didn't take me more than 5 hours working alone to change the whole truck, and I had to hacksaw 2 mounts and file 2 bolt heads. I wouldn't try doing them one at a time - you might twist the body permanently. Work down one frame rail, tighten them all back down, then move to the other side.
The rearmost bolts are the easiest to get to - just remove the tailgate
threshhold and peel the carpet back. The bolts (13mm heads)
are right there. If the heads are rusted (like mine), you can file
them down to a smaller hex so you can turn them again.
Continue peeling carpet forward and you'll see the access plates for
the next mounts, beside the wheelwells. I think the screws have 8mm
heads and all the rest of the bolts are 15mm.
The next set is just behind the front seats and I got to mine by pulling
the door threshholds, seatbelt reel covers, and kick panels (for the
next bolts). Then peel the carpet around until the access plates are
visible.
The last inside bolts are in the footwells. With the threshholds and
kick panels out, the carpet can be peeled from around the e-brake cable
and high-beam switch. I think these access plates have different screws.
The core support bolts are just outside the radiator opening on the
back side. These will be the worst because of battery acid and road
salt.
The lower section of the mounts consists of a nut welded to a round
plate with a tube sticking up. The tube has a flare near the top end.
The upper section is a plate with a tube going down that has a neck
near the bottom. At the factory, these tubes are pressed together
thru the frame with the rubber captive between the plates. This holds
them on before the body is dropped on and bolted down. It's also the
only reason this is a tricky job. The tubes lock together with corrosion
over the years and when the rubber sags, they funnel grit down onto
the bolts and their threads, making them sometimes impossible to remove
intact.
The tricks:
1. If you can con someone competent into doing it for less than $100,
get him working on it before the drugs wear off.
2. If you must do it yourself, have a good socket set with good ratchets,
extensions, and breaker bars, as well as a ball peen hammer, a blunt
drift (punch), vise grips, pry bars, a jack, 2-4 jack stands, a 6-foot
4x4 post, a hacksaw (Stanley Contractor with bimetalloy blades is the
best), anti-sieze lubricant, and all the Liquid Wrench from your state
and the 3 surrounding.
3. Soak the bolts (especially INSIDE the tubes) with Liquid Wrench
several times over the course of a week before starting.
4. Use the pry bars to lift the body and get the Liquid Wrench spray
tube on top of the top plate to fill the top tube.
5. Back up the nut from below (above on the core support) with vise
grips or wrenches so you don't twist it off the plate.
6. If the bolt won't turn, try vibrating it with the hammer & drift
(only on the head) to loosen the threads and let the Liquid Wrench
get in.
7. Work down one frame rail at a time so the body doesn't shift out
of line.
8. When you finally get a bolt out, rinse it and the hole it came
out of with Liquid Wrench and thread it back in about 5 turns. Put
the drift squarely on top of the head and smack it with the hammer.
After you lose a few fingernails, the tubes will separate and the
bottom section will drop out.
9. BIG TIP ! ! ! Coat the threads with "Anti-Sieze Lubricant" !!!
(I use it on everything.)
10. If the bolt won't turn, or the head strips, or the nut breaks
off, you will have to hacksaw through the tubes. Do it as high as
you can so you can reuse the lower section when you eventually separate
them. If the bolt breaks, you can still separate the tubes with the
drift and get the bolt out later. Don't be afraid to rip the old rubber
out of your way - you won't be reusing it.
11. When you have an entire side free (even if there are mounts that
need to be hacksawed), put the post under the door running front-to-back
along as many body reinforcements as possible. Then use it to lift
the body with the jack - 2 inches should be plenty. Don't go too high
or you'll damage the fuel filler and the fan or shroud. Later models
also have ground straps that may be too short, but they can be pried
off and hammered back on.
12. Remove the old mounts (by hacksawing if necassary) and top sections
and immediately replace them with the new ones. (You should have already
prepared them per mfr. instructions.)
13. Lower the body straight back onto the new mounts and reinstall
the bottom sections and bolts (this is where an assistant is handy).
If you must buy new bolts, get at least grade 5 or class 5.5; grade
8 or class 8.8-10.8 is better.
14. If you have a mechanical clutch linkage (like me), adjust it.
Automatics may have to adjust the shift linkage."
and of course our good friend
Justshootme has a lot of info on his body mount/cage installations
I've seen people weld plates in there, etc. so strip it back and see what the damage is