Topic: Proper length for 67 - 68 battery hold down bolts?

[Murf]

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?

[BillEBobb]

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!

[CharlesTurner]

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.

[Murf]

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. 

[DTruitt]

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

[Murf]

Danny, I am too stupid to post a picture here.  Will try and send it to you at home.

[J_Speegle]

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

[gtamustang]

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...

[Murf]

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. 

[J_Speegle]

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

[Murf]

Thanks, Jeff.  Now we have something to help in duplication.  Again, the images and support you provide are appreciated very much.

[rockhouse66]

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.