Why is 19/32ths in the wrench repertory?

I replaced the starter motor in my old Jeep today. Of the two bolts that hold it to the housing, one has a 9/16ths hex head, and the other a 19/32nds. It took a few socket changes (every time in and out under the vehicle) to remember that the last time I changed the starter a 19/32nds was wanted for one side. I don't understand why the bolt head size would vary so slightly in this instance. And why a 32nds dimension socket (or other wrench) should get into the replacer's vocabulary at this juncture. The other peculiarity of the starter is that one side of its own housing is threaded, and one side of the vehicle bell housing is threaded. And the bolts go in in 180 deg to each other. Clearance dictates this, I'm sure; but why the differing bolt head sizes?

32nds socket sizes don't filter down to my level otherwise (maybe, 17/32nds). Another of those just wondering posts. Frank Morrison

Obmetal: (And, no, I wasn't bright enough to disconnect the battery before getting under the vehicle and addressing the starter with metal wrenches)

Reply to
Fdmorrison
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I once had a *very* bright red allen wrench for similar reasons, once....

Jim

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Reply to
jim rozen
19/32 is so close to 15mm that you couldn't see the difference.

Reply to
FuhhKyu

Saw 12 volts get across my brother's watch bracelet while he was changing the starter on his '56 Chevy. Burnt him big time. Wrecked the watch. I was fortunate to be very young when I learned that lesson.

Garrett Fulton

Reply to
Garrett Fulton

I would like to know who orchestates this , do they all get together like the mob and say there must be a chaotic standard ? One would think that after a good 100 years that they could build an engine with only 3 to 4 different sized wrenches . Dash pannels really mess with me , its like they have to give the engineers something to do. Ok, we're going to buy from 15 different screw comanies to put one thing together. Somehow the mind set is that they will come back to buy another piece of crap cause we have a deal with everyone else in the world to screw them up like us and they won't have a choice but buy another time unwarrented fixable vehicle.

I got to see someone pull their skin off all at once from a class ring with a starter cable and the frame .

Reply to
Sunworshiper

Second son was totally amazed when he couldn't find the needed 19mm among my miscellaneous good tools so I handed him an old reliable 3/4" Gerry :-)} London, Canada

Reply to
Gerald Miller

I donno, looks like 0.003" differance from here! Greg

Reply to
Greg O

Buddy of mine broke his arm when his Volkswagon decided to drive off with him under it.........

Disengage the gear train or disable the ignition at the very least............

Reply to
"PrecisionMachinist"

I learned the same lesson on a 61 Chev. Laid the watch across the battery and inner fender. Flung around fast enough to fling the watch off and it crushed against the wall. I haven't worn a watch or ring in over 35 years. lg no neat sig line

Reply to
larry g

Sunworshiper wrote: (clip) I got to see someone pull their skin off all at once from a class ring with a starter cable and the frame . ^^^^^^^^^^^ My suggestion is to remove the GROUND cable at the battery. Wedding rings (including mine) can be very hard to get off. Why the ground? If you take off the 12v connection, there is a chance to brush the tool against ground. This is not a hazard on the ground side. And, once the cable is off, the rest of the job will be spark-free and burn free.

Reply to
Leo Lichtman

GM is about the worst when it comes to changing bolt sizes and heads. When the oil pump failed on my 86 pick-up, it took metric, SAE and Whitworth tools to drop the pan and change the pump. The alternator had three different bolt sizes on it. One was SAE head and thread, one was metric head and SAE thread and the third was all metric. It was a nightmare to work on. The rest of the truck wasn't much better...mixed standard hardware all over the thing, and not a single assembly that I ever found that had only one standard used in it.

Craig C. snipped-for-privacy@ev1.net

Reply to
Craig

slightly in this

wrenches)

See thread: Plumbing Conspiracy I guess you could pound a good 19/32 on to a worn out 9/16 bolt head. Otherwise,you could follow wrenching back to pre US standards relating to pipefitting(see thread),shipfitting, or weaving. Or else Uncle Sam had a hand in it.

wws

Reply to
wws

19/32 = 15mm. The thread in the starter was dictated by the supplier and the thread in the bell housing was decided by the engine manufacturer.

John

Reply to
John Manders

My Ford pickup has Imperial hardware on the engine, and metric everywhere else. Built in Canada. I could imagine a metric starter being used on a AMerican-made jeep My Dad and his father were both millwrights and mechanics, and I have several of their old wrenches, including 32nds types. In the old days there were many ideas about bolt and nut head sizes, and some auto and aircraft manufacturers made their own hardware. There was a huge variety of sizes, thread pitches and shapes and so on until the industries standardized to the stuff we see today. 11/32 is a common wrench used on light aircraft (fits #8 nuts) and is never seen in any wrench set except for perhaps ignition wrenches. Had to find one separately. I can see where there may have been a metric starter attached to an American Jeep, and the threaded hole in the starter may be metric, not 19/32.

Dan

Reply to
Dan Thomas

GM Norrh America never uses a Whitworth, So I'll assume you mean Vauxhall.

GM North America had metric transmissions, metric engines, standard transmissions, and metric transmissions. Each component was either ALL metric, or ALL standard. The bodies used to have some of each, with metric screws etc died blue.

Reply to
clare

When I tried to remove the spare tire winch on my '90 Lumina APV, the heads on the bolts holding it in place were an exact fit in a 3/8" socket, so I was very gentle with them. Increasing the effort to the point of not so gentle application of a 16 oz. hammer, they finally came loose. Turns out, they are 8mm bolts with flanged 3/8" hex heads. When it went back together, it was with standard fasteners, to h*ll with the couple grams of weight reduction! I have also seen the scooped out bolt heads that collapse when you try to use standard open wrench on them, the only way to work these puppies is a six point box or socket. Gerry :-)} London, Canada

Reply to
Gerald Miller

Well, lets put it this way.... Mine was mixed in every assembly we and two local shops ever worked on. And yes, I did have to get my Whitworth tools out to get the appropriate socket to remove one bolt on the oil pan. 5 different wrench sizes on the oil pan.

As to the blue markings...they were random...

Craig C. snipped-for-privacy@ev1.net

Reply to
Craig

I've come to the conclusion that GM installs fasteners with a shotgun. Whle an 'assembly' (like a gearbox) might be all metric, the bell housing mounting bolts and other external fasteners could be either metric or imperial or both.

-Carl

Reply to
Carl Byrns

What's really funny is that no matter how much I despise GM vehicles, we've ended up with nothing but GM's here at the house. I've been trying to get rid of every GM I've owned since the 86 got wrecked. No matter how hard I try, by some quirk of fate, I always end up with a GM product. Fortunately, after the first of the year, the one GM we own and the family loaner GM truck are going away......

Craig C. snipped-for-privacy@ev1.net

Reply to
Craig

What's really funny is that no matter how much I despise GM vehicles, we've ended up with nothing but GM's here at the house. I've been trying to get rid of every GM I've owned since the 86 got wrecked. No matter how hard I try, by some quirk of fate, I always end up with a GM product. Fortunately, after the first of the year, the one GM we own and the family loaner GM truck are going away......

Craig C. snipped-for-privacy@ev1.net

Reply to
Craig

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