Gas float sending unit

[OutpostM37]

I installed a new sending unit a year or two back. These do not seem to be the most robust of devices. Gave up the ghost, gauge is fine, sending unit resistor wiper dead. Anyone found a more robust sending unit for these M37 trucks?

 

[foxtrk2]

I put one in my truck six years back, got it from vintage, only thing id advise is to besure all things in your system match and are in good shape ie wireing from front to back , that gauges match with right connectors. I tried using metal and rubber connectors and they wont work together .also be sure the time frame for the fuel guage matches sending unit again an older guage wont work right with a newer sending unit

 

[Usmcmoose]

I understand how the fuel sending unit and fuel gauge work, (need to have the same ohms resistant's).
I rewired the unit to the gauge along with a new electric fuel pump wiring.
The problem I have is the sending units I get are poorly made and fail fast or junk right out of the box. I know they are imported. Most companies, state no returns on electrical parts, so I'm/were screwed.
I found a company GTSU (https://www.gastankdepot.com/gtsum37-sending-unit-for-1951-1968-dodge-m37-truck.html ) that carries a fuel sending unit for the M37. Looks different from the ones I bought from other vendors.
Take a look and let me know what you think. Second, I have also been looking up automotive type sending units to use, and then match a gauge to it (ohm wises). The one problem I have so far is the tank opening being a different size. Will need to make a adapter piece for it. I d not mid paying for the parts I need, I just want them to work.
Thanks Moose

 

[OutpostM37]

I understand how the fuel sending unit and fuel gauge work, (need to have the same ohms resistant's).
I rewired the unit to the gauge along with a new electric fuel pump wiring.
The problem I have is the sending units I get are poorly made and fail fast or junk right out of the box. I know they are imported. Most companies, state no returns on electrical parts, so I'm/were screwed.
I found a company GTSU (https://www.gastankdepot.com/gtsum37-sending-unit-for-1951-1968-dodge-m37-truck.html ) that carries a fuel sending unit for the M37. Looks different from the ones I bought from other vendors.
Take a look and let me know what you think. Second, I have also been looking up automotive type sending units to use, and then match a gauge to it (ohm wises). The one problem I have so far is the tank opening being a different size. Will need to make a adapter piece for it. I d not mid paying for the parts I need, I just want them to work.
Thanks Moose

USMCmoose, I will give one of these a shot. The previous sending unit starting flaking out after about a year and is non functioning now. I do have the 20 gallon S10 tank that several people are using. When I purchased the M37, it was in sad shape. The gas tank was replaced with 12 gallon tank. Enough to get me to town for coffee and back. LOL
I had to fab a new top flange out of thin sheet steel to cover the hole in the S10 tank properly. Seems to work ok. I just do not want to buy another sending unit to have it fail in 1-2 years again. These are not robust units. looking at the wiper/resistive pad that it slides on = very light duty. Attached are several pictures
first is the old rusted 12 gallon tank that came out of the M37
The new S10 tank is shown with the float and the rod adjustment to read close to zero when the float sits on the bottom of the tank. This new tank has baffling that must be accounted for.
Fabrication of the flange collar to seal the tank/sending unit.
Several tests with the VOM to check float at empty and full conditions. I used a zip tie attached to the float rod and lifted it mimicking a full tank condition. See the black plastic clamp holding the float to the full level.
A good ground cable is attached to the bolt that mounts the sending unit.
Hope this helps anyone with similar gas tank issues.

.

 

[Usmcmoose]

Outpost
That was good intel. I did not know about the S10 gas tanks. Just thinking out loud; Use that tank along with the S10 sending unit and match a gauge to the sending unit ohms. The only thing is the total cost. But if it works well and lasts a long time, then it might be worth the added expense. Its a good thing we do this ourselves, labor would be expense. Thanks Moose