Topic: Changing #4 body mount
in Forum: C3 Body
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I need to change my #4 body mounts on my 1978. One of them is shot.I'm doing this with the body on. I've broke the bolts loose but my concern is when I remove it is the nut inside the support welded to something or will I never be able to get the bolt to the nut. Also the spacers are a concern with alignment to the bolt. Any suggestions or comments.
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Hot Springs, AR - USA
Joined: 4/24/2004
Posts: 3236
Vette(s): 69 Conv #'s match 427, TKO-600/.64, 3.36HD-Posi, HT, T/T, PS, PB, PW, SP, Leather, Comp XE264HR & Roller Rockers & Lifters, Air-Gap RPM intake, Holley St Av 770 VS, MSD 6AL+Dist+Blaster SS, K&N, Jet-Hot Hooker Side-Pipes, Steeroids, Al Rad, Spal Fans
Kenny78 said: I need to change my #4 body mounts on my 1978. One of them is shot.I'm doing this with the body on. I've broke the bolts loose but my concern is when I remove it is the nut inside the support welded to something or will I never be able to get the bolt to the nut. Also the spacers are a concern with alignment to the bolt. Any suggestions or comments. |
the little cage in there allows the bolt to move a little.. of one mine rusted out and the other broke out.. i was able to get a new nut in the hole and move it with a large twelve point socket..
then inserted the bolt and began threading.
Ben's pretty much on it, I had a similar prob with both of mine. New bolts, new nuts. I put a thick body washer under the nut on mine and used a square nut and lock washer. Tightened right up.
BTW, I had to cut both of the old bolts out from underneath.
BTW, I had to cut both of the old bolts out from underneath.

They can be fun to get out. How are the rest of the mounts? Usually if one is bad so are the rest. Pull the carpet back and you will find the nut is only held in place by a cage that is riveted to the fiberglass. The metal plate on the bottom is riveted to the fiberglass also. Grind off the rivets and it will come off fairly easy.
Brian - NCM Lifetime Member
73 coupe L48, Flat-top pistons, Performer RPM Heads, Crane Cam and roller rockers, Holley 650 vac sec. Performer intake,
3.55 gear BTO 200-4R trans,
Leather seats, Seatbelt Plus 3point seatbelts, Pioneer CD player
Magnaflow Exhuast System
Dewitt radiator and dual electric fans
Borgeson Steering box

Thanks for the information. Tomorrows project will hopefully go smooth now that I have some tips. Will let you know how things work out. 


Kingston, PA - USA
Joined: 11/26/2003
Posts: 636
Vette(s): 1977 L-82 originally white/buckskin interior.
Currently undergoing a frame-off resto. and modifications.YEEHAW!!!
Ron 78 said: Ai'nt nothin goes smooth,with these old cars,except the green stuff in your wallet,it goes right out the window! |
HAHAHAHAHA



How true!!!
If you broke the bolts loose, hopefully, they are truly broken loose, and you didn't rip the cage nuts from the fiberglass. The cage nuts on my 77 were frozen, and like an idiot, I just tried to loosen the bolts from underneath, and BANG!!! I broke the whole deal.
I had to lay new fiberglass, after I removed the nuts with a sawzall, then drill new holes in the fiberglass, and then mount everything back together. That was a fun job, trying to wiggle in there, and actually see what you're doing.
Good luck.
Alan

I think the #4 mounts tend to get worse first in a convertible. They're down in a hole that doesn't drain. Between washing and getting caught in the rain with the top down, it's the first place water can go.
All my other mounts came out just fine, and I have a fairly rust free car. It's been stored inside since '89.
All my other mounts came out just fine, and I have a fairly rust free car. It's been stored inside since '89.

in Forum: C3 Body
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