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'Bolter
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This was in a box of miscellaneous parts when I purchased my project. (1940 cab, '37-'39 bed, 1947 chassis)

It has a 5/16" thread.

It looks like something that "When you need it, you need it!"

Thanks
Attachments
IMG_9998.JPG (141.82 KB, 217 downloads)
IMG_9999.JPG (54.63 KB, 216 downloads)


Nick
1940 KC Model 1/2 Ton Pickup Project
(with '37-'39 Bed and what we think is a '42-'46 Frame)
Taos, New Mexico
Joined: Sep 2010
Posts: 1,717
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back yard wrench turner
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Possibly the pivot bolt for the vent in front of the windshield?


Wayne
1938 1-Ton Farm Truck
Stovebolt Gallery Forums
1989 Silverado
1996 Mustang GT convertible
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'Bolter
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Hi Nick, Somebody else found a similar one of those recently. Yours is a hex, the other one was slotted. Maybe a variation?

Here's the link.

https://www.stovebolt.com/ubbthread...87131/anyone-recognize-these#Post1587131


1950 Chevrolet 3100 (Ol' Roy)

1939 Packard Standard Eight Coupe (The Phantom) | 1956 Cadillac Coupe de Ville (The Bismarck) | 1964 Ford Galaxie 500 coupe |1966 Ford Mustang (Little Red) | 1969 Pontiac GTO (The Dishpit) I 1979 Ford F-100 | 1976 Ford F-150 (Big Red) | 1995 Ford F-150 (Newt)
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The part I have is similar, but not the same. It may have the same/similar application though.

This one is 1 1/8" long overall and has a 1/2" hex head.


Nick
1940 KC Model 1/2 Ton Pickup Project
(with '37-'39 Bed and what we think is a '42-'46 Frame)
Taos, New Mexico
Joined: May 2015
Posts: 11,152
Housekeeping (Moderator) Making a Stovebolt Bed & Paint and Body Shop Forums
Housekeeping (Moderator) Making a Stovebolt Bed & Paint and Body Shop Forums
Joined: May 2015
Posts: 11,152
If it's oily, it's likely the bolt that holds the oil pump in place. It would have a jam nut on it as well. Here's a pic of a 235 I was tearing down. The 216 has the same retaining bolt (2nd Pic.)
Attachments
IMG_7621.JPG (33.74 KB, 191 downloads)
IMG_7757.JPG (227.81 KB, 187 downloads)

Last edited by klhansen; 03/05/2026 11:04 PM. Reason: added 2nd picture

Kevin
1951 Chevy 3100 work truck
Follow this saga in Project Journal
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1929 Ford pickup restored from the ground up. | 1929 Ford Special Coupe (First car)
Busting rust since the mid-60's
If you're smart enough to take it apart, you darn well better be smart enough to put it back together.
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Gearhead, Stovebolt Tech and Parts Tracker, Mod for Swap Meet and GTT
Gearhead, Stovebolt Tech and Parts Tracker, Mod for Swap Meet and GTT
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I'd say Kevin has this one pegged. Here's a screen shot from a Chevy Master Parts Book showing the exploded view of the earlier oil pump with the retaining bolt and associated hardware. Good catch Kevin! thumbs_up
Attachments


~ Dan
1951 Chevy 3 window 3100
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Great! I will label it as such so that we don't have to figure it out again.

Thanks!


Nick
1940 KC Model 1/2 Ton Pickup Project
(with '37-'39 Bed and what we think is a '42-'46 Frame)
Taos, New Mexico
Joined: Mar 2010
Posts: 10,305
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Renaissance Man
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The tip looks too long and the wrong shape for the oil pump retainer bolt.


1952 5-window - return to "as built" condition | 1950 3100 with a 235 and a T-5 transmission
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Well, shucks! I thought we had it nailed. I could post more photos if it would help.


Nick
1940 KC Model 1/2 Ton Pickup Project
(with '37-'39 Bed and what we think is a '42-'46 Frame)
Taos, New Mexico
Joined: May 2015
Posts: 11,152
Housekeeping (Moderator) Making a Stovebolt Bed & Paint and Body Shop Forums
Housekeeping (Moderator) Making a Stovebolt Bed & Paint and Body Shop Forums
Joined: May 2015
Posts: 11,152
I may have a spare I can measure. I'll look in the morning.


Kevin
1951 Chevy 3100 work truck
Follow this saga in Project Journal
Photos
1929 Ford pickup restored from the ground up. | 1929 Ford Special Coupe (First car)
Busting rust since the mid-60's
If you're smart enough to take it apart, you darn well better be smart enough to put it back together.
Joined: May 2015
Posts: 11,152
Housekeeping (Moderator) Making a Stovebolt Bed & Paint and Body Shop Forums
Housekeeping (Moderator) Making a Stovebolt Bed & Paint and Body Shop Forums
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Originally Posted by klhansen
I may have a spare I can measure. I'll look in the morning.
Don't have an extra. Sorry. It went away with the engine, apparently.
I'm pretty sure that it is the oil pump retaining screw, contrary to what Carl says. I think the tip shape doesn't matter, It just depends on the diameter of the pin where it goes into the blind hole in the oil pump. If someone has an engine that's partially torn down they could measure to confirm.

Last edited by klhansen; 03/08/2026 8:39 PM. Reason: fixed spelling

Kevin
1951 Chevy 3100 work truck
Follow this saga in Project Journal
Photos
1929 Ford pickup restored from the ground up. | 1929 Ford Special Coupe (First car)
Busting rust since the mid-60's
If you're smart enough to take it apart, you darn well better be smart enough to put it back together.
Joined: Feb 2004
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Kettle Custodian (pot stirrer)
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The oil pump setscrew has a bigger thread, 7/16, I believe, and the tip has a taper, not a stepped down round tip. The jam nut has a 5/8" wrench size.
Jerry


"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
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Housekeeping (Moderator) Making a Stovebolt Bed & Paint and Body Shop Forums
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Do you have one to confirm that Jerry? My recollection is that the hex head was a 1/2", which would indicate a 5/16" thread. The jam nut is larger, I'm recalling 9/16" hex. And I do think that the tip is stepped down to match the blind hole in the oil pump.


Kevin
1951 Chevy 3100 work truck
Follow this saga in Project Journal
Photos
1929 Ford pickup restored from the ground up. | 1929 Ford Special Coupe (First car)
Busting rust since the mid-60's
If you're smart enough to take it apart, you darn well better be smart enough to put it back together.
Joined: Apr 2020
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It looks very similar to a couple of bolts that hold the plate down on the top shifting 3 speed trans. The small extension goes down into a rod in the trans. I have a spare trans I can pull the bolts out tonight and compare.


1947.2 GMC 1/2T SWB panel
1947.2 GMC 1/2T long bed
1948 GMC 1/2T short bed

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Originally Posted by klhansen
Do you have one to confirm that Jerry? My recollection is that the hex head was a 1/2", which would indicate a 5/16" thread. The jam nut is larger, I'm recalling 9/16" hex. And I do think that the tip is stepped down to match the blind hole in the oil pump.

Yes, I have several engines in various stages of disassembly. I will take a few pictures, along with thread diameter and pitch measurements in the daylight tomorrow.
Jerry


"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!
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1/2" head, 5/16 coarse thread, goes in the two forward holes of the 3 speed top shifter plate. It may fit others as well but I do not know.
Attachments
1000015428.jpg (167.97 KB, 82 downloads)


1947.2 GMC 1/2T SWB panel
1947.2 GMC 1/2T long bed
1948 GMC 1/2T short bed

Joined: May 2015
Posts: 11,152
Housekeeping (Moderator) Making a Stovebolt Bed & Paint and Body Shop Forums
Housekeeping (Moderator) Making a Stovebolt Bed & Paint and Body Shop Forums
Joined: May 2015
Posts: 11,152
Rich, are you just saying it threads into the shifter plate? Did it come from the oil pump bracket? I don't know of any other bolt that has the pin end.


Kevin
1951 Chevy 3100 work truck
Follow this saga in Project Journal
Photos
1929 Ford pickup restored from the ground up. | 1929 Ford Special Coupe (First car)
Busting rust since the mid-60's
If you're smart enough to take it apart, you darn well better be smart enough to put it back together.
Joined: Apr 2020
Posts: 322
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It goes through the top plate into the trans. The tight group of 4 bolts (1 is missing) in the center mount the gear shift.
Attachments
1000015429.jpg (217 KB, 76 downloads)


1947.2 GMC 1/2T SWB panel
1947.2 GMC 1/2T long bed
1948 GMC 1/2T short bed

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'Bolter
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Originally Posted by Twin Jimmys
It goes through the top plate into the trans. The tight group of 4 bolts (1 is missing) in the center mount the gear shift.

It's in my 1929-51 parts book...

Group 4.312...Gear Shifter Shaft and Yoke Lock Screw...1940-47...ALL COMM (3-speed)...shaft lock (5/16-18 x 15/16 to end)...p/n 590863...2 required.

Mike B smile


Mike Boteler

1956 Chevy 3100 Resto Rod
1952 Willys M38 Army Jeep
1983 Jeep CJ7 Laredo
1984 Jeep CJ7
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'Bolter
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Thanks for identifying it!
I am going to make a note of the group and part numbers and put it in a plastic bag with the part in case I ever need it!


Nick
1940 KC Model 1/2 Ton Pickup Project
(with '37-'39 Bed and what we think is a '42-'46 Frame)
Taos, New Mexico

Moderated by  klhansen, Rusty Rod 

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