'66 Battery Hold Down "J" Bolt

[Rob A.]

Although it appears to be a simple piece, I assume there is some distinguishable difference between an original and a repro?

[Mike M.]

Re: '66 Battery Hold Down "J" Bolt

Yes, usually the re-pops are about an inch too long with the configuration of the end of the thread being non-typical of factory production.
HaND

[David L.]

Re: '66 Battery Hold Down "J" Bolt

I am resurrecting this thread to confirm that the battery hold down bolts in the photo beloe are original equipment from my 1966 Corvette (Feb. 24th).

The J-bolt, GM # 3688699, measures as follows:
8 3/4" in overall length
8 7/16" effective length
1 3/4" thread length

The stud, GM # 3715712, measures as follows:
9 3/8" overall length
1 1/16" thread length at each end
My 1966 Chev. Parts Catalog describes GM # 3715712 as "STUD, retainer (5/16-18 X 9 21/64" - thd. both ends) clamp".
9 3/8" = 9 24/64", close enough

The wing nut, GM # 148313, measures 1.31" long, 0.67" diameter, 0.26" ear width, max. ear width = 0.30".

The seriously pitted washer, GM # 446363, measures about 0.40" I.D. X 0.85" O.D. X 0.07" thickness.
In Gr. 8.929 of my parts catalog GM # 446363 is described as 3/8" X 7/8" X 7/64" (0.38" X 0.88" X 0.11").

I would appreciate any comments.

Dave

[Henry J.]

Re: '66 Battery Hold Down "J" Bolt

David:

If you don't get a reply to your question, please contact me in late April when I retrieve my 66 from winter storage. I'm sure my pieces are factory originals and will be pleased to check for you.

[R N.]

Re: '66 Battery Hold Down "J" Bolt

David:

If you don't get a reply to your question, please contact me in late April when I retrieve my 66 from winter storage. I'm sure my pieces are factory originals and will be pleased to check for you.

Hi Henry,

I'd like to know too - keep me in the loop please.

[Bill C.]

Re: '66 Battery Hold Down "J" Bolt

Resurrected again, was anyone ever able to confirm Davids dimensions as being originals? I wonder the same regarding the two j-bolts used on a/c or 396 cars. I assume those may be a bit longer?

[David L.]

Re: '66 Battery Hold Down "J" Bolt

Bill,

GM # 3688699 is the part number of the battery J-bolt as per my 1966 AIM. GM # 3688699 appears in my 1957 Chevrolet Parts Catalog (Mar. 1957) in Group 2.334 and is described as "hook hd. 5/16-18 X 8 7/16 overall". This agrees with the measurements of the original battery box j-bolt from my 1966 (see photo on my 02/23/2013). According to Chevrolet Parts History GM # 3688699 was replaced with GM J-bolt # 6255817 in October 1960. GM # 6255817 is described as "hook hd. 5/16-18 X 8 1/8 O.L.".

Apparently J-bolt # 3688699 was discontinued in October 1960 as a service part but it was still used on the assembly line in later years.

I could not find anything about the 3710340 J-bolt that was used on AC & 396 models in any of my many vintage Chevrolet parts catalogs. However, my GM "Part Number Replacements and Supersessions" catalog (effective Sept. 1978) shows that GM # 3710340 was replaced with GM # 3688699 but no exact dat was given for this part number change.

I have a feeling that the 3710340 J-bolt measures 5/16"-18 X 8 3/16" (slightly shorter than the 3688699 J-bolt). Type in "3710340 bolt" on google. You will be referred to a GMC Parts Catalog (Sept. 1963) and then look in Gr. 7.7770. GM # 3710340 was replaced with GM # 3688699. The length of the 3688699 J-bolt is 8 7/16" as per my Chevrolet parts catalog so, in my opinion, the 3710340 bolt must have been 8 3/16" long. I have noticed that when part numbers are changed in the parts catalogs the description sometimes does not always get changed correctly.

Dave

[Bill C.]

Re: '66 Battery Hold Down "J" Bolt

David,
Thanks very much for the update!
Bill

[Tom S.]

Re: '66 Battery Hold Down "J" Bolt

Kurt,
i found your 67 car on one of my GM Canada Shipping microfische's.
I sent it to your business email.
tom

[R N.]

Re: '66 Battery Hold Down "J" Bolt

Kurt,
i found your 67 car on one of my GM Canada Shipping microfische's.
I sent it to your business email.
tom

Got it - many thanks Tom!