Author Topic: Proper length for 67 - 68 battery hold down bolts?  (Read 4127 times)

Offline Murf

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Proper length for 67 - 68 battery hold down bolts?
« on: December 19, 2009, 01:47:58 PM »
In the current issue of MM Bob Perkins notes that it is common to find that most 67 and 68 Mustangs have battery hold down bolts that are too long, and that the current reproductions as well as many NOS bolts are longer than the original assembly line parts.  Can someone with the "real thing" provide an overall length that is correct for these parts?  Shortening them "about 3/4 of an inch" could be better stated by providing the correct measurement.  I guess most will have a group 24 battery, but if a group 27 was used and it is different than the 24 perhaps someone will provide that length as well?
John Murphy

1965 "K" GT fastback Honey Gold exterior, Ivy Green and White Pony interior, many options
1966 Conv., high option, removeable hardtop, thermactor "C" engine, AC, Springtime Yellow exterior, Black Pony interior
1968 California Special, "J" code, ,many options, white with red interior

Offline BillEBobb

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Re: Proper length for 67 - 68 battery hold down bolts?
« Reply #1 on: December 19, 2009, 11:52:22 PM »
That is a wonderful question!  It's the same thing for '69s as well.  In two different MCA National shows the hold down bolts on my car were "dinged" for being the wrong length, but I have yet to learn what the "right length" actually should be!

Offline caspian65

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Re: Proper length for 67 - 68 battery hold down bolts?
« Reply #2 on: December 23, 2009, 01:05:22 AM »
Perkin's sent this to me:

67-69 is Ford Part # C5AZ-10756-A    8 5/16 length
70-71 is Ford Part # D0AZ-10756-A    8 5/8 length      The 70 holdown is thicker.
Charles Turner - MCA/SAAC Judge
Concours Mustang Forum Admin

Offline Murf

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Re: Proper length for 67 - 68 battery hold down bolts?
« Reply #3 on: December 23, 2009, 11:48:34 AM »
Thank you, Charles.  A member of another forum sent me some images of an original and it looks as if there are about ten or twelve threads extending past the top of the nut on the factory issue hold downs on a 68.  The battery tray construction will have an effect on how much thread extends past the nut, so check before cutting if you have a reproduction battery tray. 
John Murphy

1965 "K" GT fastback Honey Gold exterior, Ivy Green and White Pony interior, many options
1966 Conv., high option, removeable hardtop, thermactor "C" engine, AC, Springtime Yellow exterior, Black Pony interior
1968 California Special, "J" code, ,many options, white with red interior

Offline DTruitt

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Re: Proper length for 67 - 68 battery hold down bolts?
« Reply #4 on: December 23, 2009, 05:24:03 PM »
Thanks, Charles.  A few people have told me to cut my hold down bolts down; but I have resisted not knowing the demensions.  This will be helpful.

Murf,
Can you re-post the picture here?

Danny
1968 Raven Black, S- Code, 4 spd., GT Fastback, San Jose, March 1968
1968 Candy Apple Red, J- Code, C-4, GT Convertable, San Jose, April 1968 (SOLD)
1968 Raven Black, R- Code, 4 spd., GT Coupe, Dearborn, April 1968

Offline Murf

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Re: Proper length for 67 - 68 battery hold down bolts?
« Reply #5 on: December 23, 2009, 05:46:05 PM »
Danny, I am too stupid to post a picture here.  Will try and send it to you at home.
John Murphy

1965 "K" GT fastback Honey Gold exterior, Ivy Green and White Pony interior, many options
1966 Conv., high option, removeable hardtop, thermactor "C" engine, AC, Springtime Yellow exterior, Black Pony interior
1968 California Special, "J" code, ,many options, white with red interior

Offline J_Speegle

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Re: Proper length for 67 - 68 battery hold down bolts?
« Reply #6 on: December 23, 2009, 08:06:46 PM »
One of the challenges for all will be to get the end looking as if it wasn't cut.

But a little work and some experimenting should produce something (since it sticks directly towards the viewer) that looks original
Jeff Speegle

Anything worth doing is worth doing concours ;)

Offline gtamustang

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Re: Proper length for 67 - 68 battery hold down bolts?
« Reply #7 on: December 24, 2009, 11:58:40 AM »
It takes a little work but a thread restorer, fine-stone grinder, and phosphate/oil does the trick for me.

After cutting j-bolts to the correct length using a hacksaw, I use a thread restorer to chase the threads (left the chase on through the end of the next step). Then I put the cut end up to a grinder to smooth the end surface and to duplicate the bevel on the end. After getting the end the way I want it to look, I dip them in the phosphate solution, rinse them in water, and spray with oil.

Of course, your mileage may vary...

Offline Murf

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Re: Proper length for 67 - 68 battery hold down bolts?
« Reply #8 on: January 02, 2010, 11:23:13 AM »
Duplicating the ends of the threaded hook is interesting.  Is it possible that anyone can post an image of an original battery hold down bolt showing the end in detail?  Reproducing something one has never paid attention to or has never seen is tough - a picture of the real thing could make this job much easier. 
John Murphy

1965 "K" GT fastback Honey Gold exterior, Ivy Green and White Pony interior, many options
1966 Conv., high option, removeable hardtop, thermactor "C" engine, AC, Springtime Yellow exterior, Black Pony interior
1968 California Special, "J" code, ,many options, white with red interior

Offline J_Speegle

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Re: Proper length for 67 - 68 battery hold down bolts?
« Reply #9 on: January 03, 2010, 12:27:06 AM »
Duplicating the ends of the threaded hook is interesting.  Is it possible that anyone can post an image of an original battery hold down bolt showing the end in detail?  Reproducing something one has never paid attention to or has never seen is tough - a picture of the real thing could make this job much easier.

Here to help







Jeff Speegle

Anything worth doing is worth doing concours ;)

Offline Murf

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Re: Proper length for 67 - 68 battery hold down bolts?
« Reply #10 on: January 04, 2010, 11:46:15 AM »
Thanks, Jeff.  Now we have something to help in duplication.  Again, the images and support you provide are appreciated very much.
John Murphy

1965 "K" GT fastback Honey Gold exterior, Ivy Green and White Pony interior, many options
1966 Conv., high option, removeable hardtop, thermactor "C" engine, AC, Springtime Yellow exterior, Black Pony interior
1968 California Special, "J" code, ,many options, white with red interior

Offline rockhouse66

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Re: Proper length for 67 - 68 battery hold down bolts?
« Reply #11 on: January 11, 2010, 09:35:38 PM »
Perkin's sent this to me:

67-69 is Ford Part # C5AZ-10756-A    8 5/16 length
70-71 is Ford Part # D0AZ-10756-A    8 5/8 length      The 70 holdown is thicker.

OK, now I am confused.  My repro hold down bolts measure 8-5/8" long and stick up more than an inch above the top of the nut on my '69 CJs (G27 battery).  This suggests that the repro is only 5/16" too long to be "correct"...??  Is that what this is all about?

I was planning to reduce the length of mine about 1" to bring the end of the hold down bolt just a little above the nut.
Jim
'66 GT FB, '69 CJ Grande