M38 Speedometer???

1950 - 1952, M38, questions, discussions, regarding anything related to the M38.
Post Reply
Travelfix
G-Second Lieutenant
G-Second Lieutenant
Posts: 551
Joined: Tue Oct 21, 2003 2:54 pm
Location: Dudley, MA

M38 Speedometer???

Post by Travelfix » Tue Oct 12, 2021 6:29 am

IMG_7750 (5).jpg
IMG_7749 (7).jpg
Has anyone seen one of this type of speedometer or know what or where it would have been used on. Supposedly it goes to an M38???? I've never seen one of these??? The numbers on the face of the odometer are 7527357 AC1580972 The numbers don't match the G740 parts manual but their not far off.
Bob


User avatar
dpcd67
G-General
G-General
Posts: 8798
Joined: Mon Jul 25, 2011 4:41 pm
Location: Iowa

Re: M38 Speedometer???

Post by dpcd67 » Tue Oct 12, 2021 7:40 am

Definitely not an M38; looks like it is for a submarine; note the sealed connector.
U. S. Army 28 years.
Armor Branch

User avatar
W. Winget
LTC, U.S. Army
LTC, U.S. Army
Posts: 3786
Joined: Mon Dec 16, 2002 12:37 pm
Location: USA, Virginia, Carrollton
Contact:

Re: M38 Speedometer???

Post by W. Winget » Tue Oct 12, 2021 10:04 am

More than likely an Armored Vehicle Speedo.
Why? It uses Electric drive VS cable, so they could run a sensor on a shaft and tell the speed VS plumbing in a cable.

All jeeps (from beginning to the HUMVEE) and most ground wheeled vehicles used cable driven units off the transmission or transfer case, so it's not an M38.
A photo of the face would help (especially the speed). It has the side illumination cutouts for military dash board light system of the M-series vehicles VS WWII front illumination style.
So it's on e-bay: https://www.ebay.com/itm/Vintage-AC-Mil ... 3803931871
Sold in Canada, so possibly one of their mil vehicles....
0-60 on face, illumination gel coating on the 0-30...so that's the operating speed range expected at night...but that is identical to the M38/M38A1 :D so not really that helpful.

So possibly something with rear drive like an, M88, M1 Abrams that has a long way to go to reach the drivers position making electric wiring a better solution.
(M60 tank had a 150" speedo cable so that's not it, and M88 used the same driveline, but back further, so a "maybe" here)
M2 Bradley has the PACK right next to the driver but I can't recall the speedo being electronic.
It's not something before the 70's, as Hall Effect sensor sender units weren't tiny early on, so figure late 70's and up vehicle.
V/R W. Winget

Face is close to this but numbers are off and obviously wiring behind the unit would be a pain...
Image
Looking for 1918 Standard B 'Liberty' truck parts

User avatar
dpcd67
G-General
G-General
Posts: 8798
Joined: Mon Jul 25, 2011 4:41 pm
Location: Iowa

Re: M38 Speedometer???

Post by dpcd67 » Tue Oct 12, 2021 10:51 am

Read this page; it is TACOM managed and I am not sure what it is for.
https://www.parttarget.com/6680-00-752- ... BC9800A2FF
U. S. Army 28 years.
Armor Branch

JMZ421
G-Second Lieutenant
G-Second Lieutenant
Posts: 545
Joined: Sat Jun 02, 2012 2:21 pm
Location: N.E. Ohio

Re: M38 Speedometer???

Post by JMZ421 » Wed Oct 13, 2021 3:55 am

AC-1580260 is the M38 speedometer. Several months ago I found one on ebay brand new. John

User avatar
dpcd67
G-General
G-General
Posts: 8798
Joined: Mon Jul 25, 2011 4:41 pm
Location: Iowa

Re: M38 Speedometer???

Post by dpcd67 » Wed Oct 13, 2021 8:12 am

I had a guy who used to work for me in TACOM look it up; it is/was TACOM managed but he couldn't find a use on code. It's obsolete.
U. S. Army 28 years.
Armor Branch

User avatar
W. Winget
LTC, U.S. Army
LTC, U.S. Army
Posts: 3786
Joined: Mon Dec 16, 2002 12:37 pm
Location: USA, Virginia, Carrollton
Contact:

Re: M38 Speedometer???

Post by W. Winget » Wed Oct 13, 2021 9:50 am

Might fit something like my XM104, a tracked experimental 105mm Howitzer on a mix of M151 and M114 drivetrain for example.
Hard to tell unless someone had removed and installed one in something before.
W. Winget
Looking for 1918 Standard B 'Liberty' truck parts


Post Reply

Return to “M38 Technical Knowledge Base”

Who is online

Users browsing this forum: No registered users and 5 guests