Spinning Body Mount #3 Bolt

[Kenn S.]

Like many of you, it was time for me to launch into my resto. I'm working on a 1980 so I learn and don't destroy my 1970 LS-5 waiting in the wings. Here is lesson #1 for me, a gift from the 1980 (a car I actually do love and want to get back on the road).

While removing the body bolts, #3 behind the driver's seat is loose but I have a suspicion the underlying nut is loose and spinning. I have the AIM dawing of this (shown), but never having removed these bolts before, I don't have the detailed understanding of what's under the mount (the bolt detail). #3 on the passenger side did come out. The AIM detail in this case is not of sufficent quality to tell what's going on.

I tried (repeatedly) to douse all bolts with penetrating oil to de-rust, but #'s 2 and 3 proved useless from up top (so once I find a lower access I'll douse the '70 from below, if possible).

To my questions...

1) Am I left cutting the bolt head off (challenging given limited access, so will use a Dremel)? I assume a drill/tap nut effort once I do.

2) If the nut is spun, can I deal with (repair/replace) the spun nut, and how if not obvious? (May be obvious once I lift the body.) Or is my suspicion incorrect and the nut can't posibly spin (and I'm not being patient enough)?

3) Other advice/direction?

As always, thank you for your guidance...

[Kenn S.]

Re: Spinning Body Mount #3 Bolt

Maybe to answer my own question (which often happens...as soon as I ask, I figure it out)...

The nut can indeed spin if pressed hard enough. I searched the archives as best I could and didn't strike gold, but wouldn't you know not a dozen posts before mine was Bob B's 1969 doing something similar.

Bottom line, cut the bolt head and replace the cage underneath. I found a couple of different replacement cages, so I'll order up what I need once I see which design is required. Not a show-stopper at all.

[David H.]

Re: Spinning Body Mount #3 Bolt

#3 on my passenger side (1980) also spun the nut. I took a hacksaw blade, wrapped one end with duct tape, and pretended I was escaping from prison.

[Kenn S.]

Re: Spinning Body Mount #3 Bolt

LOL... That works.

I used a reciprocating saw (same idea) and cut from the base of the head at a slight downward angle. When the head popped off, I used a Dremel tool with a grinder bit to remove the head residue. Worked great.

I was worried about cutting it off as I didn't know the nut arrangement underneath. But I've since found several outlets for the nut cages, so I'll be replacing all four when the frame is ready.

Thanks!

[Bill M.]

Re: Spinning Body Mount #3 Bolt

Kenhad same problem on my 66 I used a dremmel with a good around 1 1/8 " steel cut off wheel cut the bolt head into 6 or 8 slices and tapped it apart with a chisel. don't try sawsalling the rubber bushing flex's and the blade does not cut. took a while .Bill

[Chuck R.]

Re: Spinning Body Mount #3 Bolt

I used an air driven automotive die grinder with smaller cut off wheels and carefully ground the head off. Dremmels are a good choice, but if time is an issue, you'll be done and gone in fifteen to twenty minutes with the big gun die grinder.

Chuck