I'm in the process of replacing my body mounts, #1 and #4 reinforcement brackets and much more other stuff than I was hoping to do. I've found countless threads on the #4 bracket, but I cannot find a single one on the #1 bracket. Both of mine are shot. Does anyone have any insight on getting to the other side of the bracket for the rivets? I've looked through my AIM and everywhere else I can think of...no luck. I can't see anything under the dash. I have a bad feeling I'm going to get an answer that I don't want to hear . Thanks a bunch!

 

Are you talking about the brackets that attach to the firewall?

 

I think I might have some pics of a car I parted out that might help you.







Hope those help out.......
I have no idea how you'd remove them without removing the fender.....
I have the brackets for sale if you need them....let me know.


dodosmike

 

Hi 72,
In the 71 AIM the support (bracket) installation on UPC 1 (bolt/weld), sheet A14.
I agree that there's no way of gaining access with the front fenders bonded in place.
You'll see there's a metal backing plate on the other side of the fiberglass. If you're REALLY lucky when you drill the flat rivets out to put the new support in place, the rear plate will stay in place till you get the first pop rivet installed to hold it where it is.
Good Pictures dmike!
Regards,
Alan

I just looked again at Mike's pictures..... can you stick your hand through the kick-panel vent opening to hold the plate in place? It LOOKS like you might be able to just reach. It would probably be easy for a 5 year olds hand and arm!

 

Yes, I'm referring to the brackets that are attached to the firewall, or at least supposed to be attached. Both of mine fell off when I removed that body mount bolt.

 

Thank you for the excellent pictures. I wish my brackets looked as good as the ones in your pictures!

Alan, I will certainly try to get at those from the vent opening. Do you know if pop rivets will work in place of the solid rivets? I wouldn't mind using small stainless steel machine screws and nuts, but if I can't get behind there to get the nut on, that won't work either.

 

If you go with stainless steel bolts pay attention to the grade. Most common S/S bolts are not as strong as big box store low end bolts. Go with a strong grade 5/8 and coat the area for future rust protection.

 

I don't think "Pop rivets' would be nowhere close to strong enough!!!

 

BTW......these pics are from a NON A/C '78.....so it may not be exactly like your '72 (??)
'78's with A/C have the vents, but they are not manually operated like a non A/C car.


Those vent openings are pretty small....even for a 5 year old hands.
I'd say once they're open you'd have only 2.5" to 3" to get your hand through, let alone reach through and try and fasten a nut and bolt. and they dont open to 90* (degrees) to the opening either....more like 45*.

The flap is mounted on a verticle post like assy with a "spring" type mechanism holding it...should be able to lift out the door.


YEP.....more pics



might be best to try and remove the vent as a whole. Be careful....the springs and flaps are pretty brittle after 30 some-odd years.....

dodosmike

 

YA....buy the right stuff the first time.
Use loctite (sp?) AND nylock nuts to hold it in place.

pop rivits are aluminum and pretty soft. I wouldn't use them.

If you need the mounts let me know, I have the ones from the pics taking up space in my shop.


dodosmike

 

Hi,
I believe the original rivets were soft aluminium.
The strength was achieved by the number of rivets used and the backing plate which spread the load over a much wider area than just covered by the rivet's heads.
If you're concerned about strength there are steel pop rivets readily available. They are a bit more difficult to pop than the aluminium version, but still easy to install.
I think bolts would work too if you can gain access to the rear of the plate.
Good Luck!
Regards,
Alan

 

I just finished doing them on my friends 72. We were able to get at them with the side grills removed(body is on a Dolly) Drilled out the old rivets and used steel pop rivets to mount the new ones.

 

Well, I removed the vent door and that didn't help at all. It really looked like there might have been hope based on the above pictures, but no such luck. Maybe the '72 is different. Mine only had the door on the passenger's side, it's an A/C car, maybe that's why.

 

I replaced the #1 driver's side bracket on my '68. Oddly, while the driver's side bracket was rusted thin, the passenger side bracket on my car was perfect. At any rate, I used large head aluminum pop rivets to fasten the new bracket in place. Don't worry about the rivets not being strong enough, most of the stress in that area is carried by the #2 mounts (access behind the interior kick panels and immediately behind the #1 mounts) that attach directly to the bird cage. I did use original style rivets (which are aluminum too) in all other locations on my car but was afraid I'd do more damage than good in this case because it would involve breaking the bonds attaching the front fender and possibly ruining the pristine front end fiberglass. A little body filler in the dimple of each of the large head aluminum pop rivets and they look just like the originals when painted.

Behind the fiberglass firewall panel is a steel backing plate that the bracket rivets to. If you're lucky like I was, it will still be in good shape since it's not exposed to the elements. I was able to fish it into place through the rivet holes with a coat hanger so that all the holes lined up before riveting it into place. I believe I also used a strong magnet to help hold it in place on the back side of the fiberglass since I was working blind.

You can find replacement brackets from Vette Products of Michigan. They manufacture many of the sheet metal brackets and reinforcements used in Corvettes. They also manufacture complete frames as well as frame sections.

Good luck! I'd love to hear how your repair works out.

 

Just use this 2 part urethane structural adhesive from the front side.
It will have several times the shear strength of the oem alum rivets when properly installed.
GM uses Pliogrip from Ashland in the new vettes and other lines for structural assembly.
More flexible than epoxy.
Instructions on this link too.

http://www.tcpglobal.com/autobodydepot/pliogrip.aspx

If you are really worried you can add some of these 6.6mm (1/4"dia) pop rivets to tie in the backer reinforcement.

http://www.harborfreight.com/20-piec...2mm-67567.html

 

Thanks for all the help and ideas!

 

Maybe I'm reading too much into this picture, but the 6 aluminum cylinders missing from the plastic piece hanging in the middle of the picture might help solve your problem. At least they won't hurt.

 

MN80Vette is correct with his astute observation.

At least, that's the way my neighbor Lars would address the issue.

Good luck.

Ralph.

 

I agree....if you look just left of the "cylinder holders" you'll see what happens when a individual (not me!) consumes too many "cylinders" and drive a 'Vette...
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A few adult beverages+Vette+a ditch+motorhome+house=




And the guy lived!


dodosmike