C3 Battery reinforcement assembly

[Gary S.]

Reference 1972 AIM UPC 12 Sheet A10 and item 5, "Reinf Asm", 3919636. I've seen the repro photos of this but can't find a photo of it installed. I have the proper 1.25 inch "pointy" bolt with E marking, maybe black phospate? but the underside of my battery box doesn't have a weld nut to secure the holddown, aka clamp, via the bolt 3858700. Is this item 5 actually under the body and does anyone have a photo of it? Right now my battery has nothing securing it .

Thank you as always.

Gary

[Patrick H.]

Re: C3 Battery reinforcement assembly

There's a small bracket riveted to the fiberglass on the underside of the battery box.
This bracket has threads that the bolt screws into.
And, as you note, the aluminum rivets often corrode and the bracket falls off.

I can see it in a couple of picture of my car (posted online). However, none specifically of the bracket.

[Ray K.]

Re: C3 Battery reinforcement assembly

Gary,
The battery reinforcement assembly, (Item #5, GM #3919636) has a nut welded to it. It's attached on the underside of the battery box and held in place by two rivets (item #4, 9409245). When tightened, the "pointy" bolt (item #2, 3858700) retains the clamp (item #3, GM #3887588) and secures the position of the battery (along with clamp item #7, GM #3919633)

The "pointy" bolt is black phosphate.

My '71s at the shop and in storage right now, I can send pictures later this week (if nobody replies & posts the pictures before then).
Ray K (#43777)

[Patrick H.]

Re: C3 Battery reinforcement assembly

If you Google "Corvette battery reinforcement" you will find a lot of photos of the part.

https://www.corvettecentral.com/68-8...nt-rear-173014

[Gary S.]

Re: C3 Battery reinforcement assembly

Ray, I would appreciate photos. Ray & Patrick, I asked because the bottom of my battery box is pristine as far as my limited inspection has shown.. I am, however going to jack it up and see if the reinforcement is really there and only the weld nut has surrendered to the elements. It's wet & cold and I haven't had the time to get full under there yet.

[Gary S.]

Re: C3 Battery reinforcement assembly

If you Google "Corvette battery reinforcement" you will find a lot of photos of the part.

https://www.corvettecentral.com/68-8...nt-rear-173014

Patrick,
Thank you. However in my first post I mentioned I had seen the repro part. Further googling brought up original pieces for sale.

[Patrick H.]

Re: C3 Battery reinforcement assembly

Ray, I would appreciate photos. Ray & Patrick, I asked because the bottom of my battery box is pristine as far as my limited inspection has shown.. I am, however going to jack it up and see if the reinforcement is really there and only the weld nut has surrendered to the elements. It's wet & cold and I haven't had the time to get full under there yet.

Those rivets don't seem to take much to disintegrate, but I'll be interested to see what you find.

[Mike E.]

Re: C3 Battery reinforcement assembly

Originals of the upper clamp are a lighter gauge steel than the reproductions, btw.

[Edward J.]

Re: C3 Battery reinforcement assembly

Gary, here are some pic,s of my 72F3FB6DC8-1D52-4355-8F39-3C8CD3836DB8.jpg90FE207B-8824-4753-AD7C-FE44F6BD78E1.jpg37230FA2-7E88-4E03-8D68-80D499EEF617.jpg

[Gary B.]

Re: C3 Battery reinforcement assembly

20220412_083457.jpg
Not the best picture, but you get the idea.
Gary B

[Gary S.]

Re: C3 Battery reinforcement assembly

Great photos gents. Thank you. I'll jack the car up and crawl under to see what I have. I do have the clamp and bolt (mine is an "E" headstamp) but I'm guessing that the reinforcement is there because the rivets are still intact as viewed from the inside of the battery box. I'll post photos this afternoon

[Patrick H.]

Re: C3 Battery reinforcement assembly

You can probably just stick your phone under there and take a picture, and not have to jack it up at all.

[Ray K.]

Re: C3 Battery reinforcement assembly

Gary, Found these in my archived photos, shows the rivets and clamp.
Ray K
'71 Vette Battery Box Reinforcement - GM #3919636 - 112Apr22.jpg'71 Vette Battery Box Clamp - GM #3887588 - 112Apr22.jpg

[Gary S.]

Re: C3 Battery reinforcement assembly

I know that, Patrick. But it gets a full "coming out of hibernation" makeover to include transmission and differential fluid check so as long as I have to jack it up for that ...

[Gary S.]

Re: C3 Battery reinforcement assembly

Well, it looks like I could have saved some typing by crawling under there first. The reinforcement and rivets are all there but the weldnut is MIA. I am not sure if it shows but the bolt is an E.

reinforcement assm.jpgbattery box.jpgclamp & bolt.jpg