HELP: odd bolt size on 1985 LX

Oct 23, 2004 10 Replies
1985 Mustang LX
3.8 L V-6

I'm changing out the original corroded negative battery cable, for which there is no factory replacement available. I bought the work-around set from Napa, which seemed to fit the bill.



The negative cable has a bare-wire ground connection on the motor compartment sheet metal, then winds down to another ground on a bolt on the underside of the block. The nut on this ground post IS NOT 5/8", 9/16", 15 mm, or 16 mm. That leaves something like 19/32". Its in a tight spot (to tight for an adjustable wrench), and siezed w/ rust, I'd really like to get a socket on it instead of an adjustable wrench, but that means finding a



19/32" socket.

I'm just suspicious that they'd use a 19/32" nut. Is it so?



Thanks a heap. J.B.Bobbitt


Seems unlikely for something so common. At times manufacturers will put something like a torx bolt in a cylinder head as an "idiot protector", but I don't see that being the case here.

Is it rusty and rounded-off at all?

J.B. Bobbitt wrote:

19/32 is an old Henry Ford size.... For years Craftsman tool sets ship with both 19/32 and (IIRC) 21/32. 19/32 is so close to 15mm it makes your teeth hurt. Make sure that there isn't an scale or dirt block your wrench and that the wall of the boxed end isn't too large for the space you have. Occasionally, there may be a metal tab or such getting in the way. Also, is this bolt threaded into whatever or is there a nut on the other end? Rare or motor or transmission (common on frame and body parts), Ford will sometimes use a "captive" nut or bolt... these 'feature' a metal tab that makes it impossible to get a good purchase on the flats of the fastener.

As you might guess, cheap tools can add their own problems and turn the project into a frustrating, expensive mess.

HTH.

The post is a little rusty but the nut is in oretty good shape.

The threaded bolt sticks out of the block, and it looks like there's a thin nut on the post, up against the block. The ground cable is next, then a small metal piecethat holds a wire harness, then the nut in question. I can't see or feel any obstructions.

Thanks for the replies.

-jbb

What we see quite often is that the nut will sieze on the stud sticking up from the bolt.... we can break the bolt loose but are left with an assembly that is impossible to turn. Check to see if this has happened in your case - if so, you have my deepest condolences....

Interesting... I stand corrected... why in the?? It's like 17/64.

I defer to Jim > 19/32 is an old Henry Ford size.... For years Craftsman tool sets ship with

Wound Up opined in news: snipped-for-privacy@swbell.net:

I doubt ... do your math. And I suspect the original nut had been replaced with one from a junk box.

Quit noodling around, get a cold chisel and crack that nut from the side, then find a proper one, brass if possible.

Or, buy yourself a nut splitter. I've had one for ~20 years. I use it every year or two. It's especially good to have when the siezed nut is near fragile materials.

It is in fact a 19/32" or 37/64" nut (a 19/32" wrench has just a tiny bit of room). Go figure.

I found an old open-end combination wrench of my Dad's that fit. That and a quick pass or two with a blow torch and it came off easily.

Thanks a heap for the input.

-jbb

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