M-37 Oil Pressure {Gauge}

[rimshot]

My oil pressure gauge has been slowly showing less and less pressure.
Engine has 3200 miles on it. New everything. I bought it restored. Not sure if it's the correct gauge. It goes to 120 and barely reads above 15 now. Should it be the one that goes up to 60. It's a 1952. Could it be the sending unit? Faulty gauge? God forbid-- oil pump? Engine sounds good. No smoke. No knocking. Any ideas?

 

[NDT]

The 0-60 gauge has a specific sending unit as does the 0-120. There is a PS article about this, as the Army has been mismatching these forever. I would put a mechanical gauge on the truck temporarily to rule out the engine.

 

[rimshot]

The 0-60 gauge has a specific sending unit as does the 0-120. There is a PS article about this, as the Army has been mismatching these forever. I would put a mechanical gauge on the truck temporarily to rule out the engine.

Finally got around to checking pressure with a mechanical gauge. I had an old gauge out of a John Deere 2 cylinder tractor.. Rigged it up and it shows just above the L at idle and above the M with a few more RPMs. Who knows how accurate that gauge is but I'm pretty sure it's good enough to rule out the oil pump. So I guess I will replace the sending unit first. Any recommended vendors.

 

[rimshot]

Finally got around to checking pressure with a mechanical gauge. I had an old gauge out of a John Deere 2 cylinder tractor.. Rigged it up and it shows just above the L at idle and above the M with a few more RPMs. Who knows how accurate that gauge is but I'm pretty sure it's good enough to rule out the oil pump. So I guess I will replace the sending unit first. Any recommended vendors.

I'm having a hard time finding an original style sending unit. I found a couple that have some kind of rubber style end on it. I need an original one that twists and locks on. Any vendors you guys know of that would have one. 120psi

 

[glcaines]

Finally got around to checking pressure with a mechanical gauge. I had an old gauge out of a John Deere 2 cylinder tractor.. Rigged it up and it shows just above the L at idle and above the M with a few more RPMs. Who knows how accurate that gauge is but I'm pretty sure it's good enough to rule out the oil pump. So I guess I will replace the sending unit first. Any recommended vendors.

I would obtain a good quality modern gauge and check your oil pressure. Reading just above the L at idle on an antique gauge wouldn't give me any comfort that your oil pressure is OK. If your engine was just rebuilt, you don't want to damage it.