# 4 Body mount

[Jack P.]

I am working on replacing the # 4 body mount bushing if possible. Looks very rusty at cage nut . See photo of underbody.

And suggestions as I have not tried to remove bolt yet. I am soaking the top of bolt in deck area. I have clean the rubber from the bushing. Is the bolt surrounded by a casing (part of original bushing) You can see it in the cleaned photo.

Thanks Jack

[Paul S.]

Re: # 4 Body mount

Soak the nut like you are already doing . If the head of the bolt is still good , you can try and get on it with a socket , get someone in the car with a big screwdriver or small pry bar and see if they can hold the nut if it starts to turn . If all this fails take a die grinder with a cut off wheel and cut the bolt in half. Then replace the nut and cage when you put the body back on ( long island corvette sells them)

[Timothy B.]

Re: # 4 Body mount

That is going to be tough to get loose, it looks like you might as well get it over with and try to turn it a bit. If the cage needs to be replaced the deck lid and spring need to come out.

Hopefully others with more experience will offer opinions.

[Richard M.]

Re: # 4 Body mount

Jack,

The nut will be badly rusted. The bolt won't break because the nut will spin in the cage. If you can get a Sawzall in there with a metal cutting blade, I'd try that first. Be careful as the fuel tank is nearby.

If not, Post #6 in This Thread may help.

Rich

[Bill M.]

Re: # 4 Body mount

I used a dremmel and small metal cutting blades. cut head off cap screw like a small pizza pie. took forever

[Timothy B.]

Re: # 4 Body mount

I don't think he wants to remove the body.

[Jack P.]

Re: # 4 Body mount

Hi, no I am not going to remove body. It seems like I am looking at the liner of the bushing with the bolt in it. I will try to remove the sleeve to get at bolt before I turn it. If that fails , can I cut into the fiberglass on side of mount to reach nut ?

Jack

[Bill M.]

Re: # 4 Body mount

Jack

if you are not worried about looks you can run a cap screw and nut right through with head of cap screw under car and nut buried under carpet

[Richard M.]

Re: # 4 Body mount

Maybe a misunderstanding, but I did not remove the body on the last '67 I did. DS #4 was very bad. I was able to hold the nut with a helper and got it free. I did everything with body on. Threaded 10-24 and used screws to hold the cage.

Rich


P2200247.JPGP2200249.JPGP2200261.JPGP2200263.JPGP2230012.jpg
P2230016.jpgP2230017.jpgP2240023.jpgp2240026.jpg

Before & After
P2230009.jpgP2230013.jpg

[Timothy B.]

Re: # 4 Body mount

Richard,

Are the last two pics before and after with the same # of shims.

[Richard M.]

Re: # 4 Body mount

Richard,

Are the last two pics before and after with the same # of shims.

Here's the before of the DS #4......It looks like 4 shims. The rubber was deteriorated and caused the door gap.

P2230002.jpgP2230014.jpgP2230017.jpg

I recall and looks like 6 or 7 in the "after". The extras, with the new rubber mounts closed the gap better.

p2240026.jpg

Rich

[Jack P.]

Re: # 4 Body mount

Hello to all,


We left off with the bolts soaking and all the rubber peeled away on # 4 mount.


I went out this afternoon to soak the bolts again and while there I picked a bit at the bushing sleeve and bolt.


I decided to give the bolt a little bit of a turn. The result, the bolt came out with the nut . The nut capture cage is not rusted , but the frame mount and and mount reinforcement was rusted, one turn and out it popped.


I will let you all give me advice on what to do next. I do not weld !


Mount with rubber still on it





Bolt and nut with bushing sleeve





Frame mount and nut cage

[Jack P.]

Re: # 4 Body mount

Hello to all,


We left off with the bolts soaking and all the rubber peeled away on # 4 mount.


I went out this afternoon to soak the bolts again and while there I picked a bit at the bushing sleeve and bolt.


I decided to give the bolt a little bit of a turn. The result, the bolt came out with the nut . The nut capture cage is not rusted , but the frame mount and and mount reinforcement was rusted, one turn and out it popped.


I will let you all give me advice on what to do next. I do not weld !



Frame mount and nut cage





Side view

[Richard M.]

Re: # 4 Body mount

Ouch Jack.....A case of too much penetrant and it soaked into the fiberglass weakening the material to a point it tore it up when you wrenched it. Because the nut was rusted solid to the bolt, there was no way it would loosen. That's why several of us suggested cutting the head of the bolt. You also have a badly rusted frame mount with the typical rusted out area. But fear not, there is a way to fix you up.

Unfortunately, you've got more work to do to repair it. It's still winter in Maine so you have time before the driving season begins. I think I know you often prefer functionality over "correctness", so I will keep that in mind.

I have a few possible solutions.

Preferred method

The ideal solution is to replace the frame mount, but very difficult with the body on, and risk of fire while using a grinder to break the welds, as well as when welding a replacement bracket on.

The fiberglass damage should also be repaired after removing the oily residue with a denatured alcohol bath from the topside, letting gravity clean the fibers as it drips down. It would need much to clean in properly in preparation for a glass mat and resin repair.

To expand on the FG repair, I'd use at least 4 or 5 layers to build up to original thickness.I'd suggest laying in 1 layer at the bottom end, from underneath, covering the square area to create a "dish" to hold subsequent layers from above. Once cured, from the topside(inside the rear compartment after removing the decklid and the hinge mount), cut rounded pieces of mat and lay in several layers at a time to fill it to the proper thickness. Probably a 10 minute cure between each lay-up to get a good bond before it's totally cured, not all at once. I would add one final square layer up and inside the cavity up to the corners of the edges.

When fully cured overnight, line up your new cage and line it up to drill your hole for the bolt to pass, then 2 small holes to capture the cage later.

Install your nut in the cage and locate it in the cavity with the bolt loosely in place. Tap 10-24 through the rivet holes. Use short SS machine screws to hold the cage. You cannot re-rivet(soft rivet) the cage in place easily. Pop rivets stick down too far so those are not a good option.

P2240024.jpg



Not-So-Preferred-Method (May be considered the Bubba approach, but it'll work. )

Clean out the oily residue out of the FG as explained above. Get a piece of 12 or 14 gauge aluminum plate and cut it to fit in the well of the fiberglass cavity from above. I'm suggesting aluminum so it won't rust. Locate the center of it and drill the hole for the mount 7/16" bolt, probably go 1/2" diameter. This will be a easy but strong enough way to capture the body and reattach to the frame later. You will not be using a cage nut as original.

Now for the frame bracket......Acquire a very large steel washer, like a fender washer. Enlarge the hole so it will accommodate the lip of the new rubber mount. Lay that on top of the frame mount after cleaning and painting the top of the bracket for future rust prevention. Use a new 7/16" bolt of proper length and flat washers to attach the mount up into the body and aluminum plate. Have a helper wrench it tight. Anti-seize everything threaded.

Here you can see what I had in front of me once. I could not change the bracket either on this one.
P2230020.jpgP2230021.jpgP2230022.jpg

You can barely see the edge of the big washer I added, laying on top of this rusted bracket.
P2240025.jpg

On the left, the washer is seen below the rubber mounts.
P2230016.jpg

The result....functional, yet barely noticeable.
p2240026.jpg

Rich
p.s. you had duplicate posts last night and I replied to the first.

[Jack P.]

Re: # 4 Body mount

Thanks Rich, just what I needed to make a decision . I don't know if my body can handle the rear deck glass work (hips , knees fake)

the nut cage is solid, a plate above and below , plus the frame bracket washer may do the trick.

Jack