M37 lubricants and fluids

[55CanuckM37]

Hey everyone, new member and owner of a 55 M37 canadian model. What are acceptable modern lubricants and fluids to use for:
-engine oil
-transmission oil
-transfercase oil
-front and rear differentials
-brake fluid

I plan on restoring it, but for now i just want to drive it! Thanks in advance for any recommendations.

 

[poppop]

Welcome aboard!! I have just acquired an M37 myself. This is what I think and I an not the expert. Most any good engine oil is acceptable and seeing your location you need to check on what viscosity is good for your temps. All gearcases on old vehicles usually require 90 weigrt GL 1 mineral oil. Brake fluid depends on what was used before. Dot 5 was used for years in mil vehicles. You can test what is in it if it still has some to see if it is Dot 5 or Dot 3. They do not mix well but the system can be flushed and either one used. The Military used Dot 5 because water will not mix with it and damage components on vehicles not driven very much.

 

[ranger.41]

55canuckm37,
I have a 1951 M-37, I run Shell Rotello 15-40 in the engine, I have Valvoline 50w synthetic racingmotor oil in the transmission, Lucas 75- 90w gear oil in the transfer case and the differentials. Dot 3 in tthe master cylinder.
ranger.41

 

[WarrenD]

You must be very careful with the lubes for the tranny and t-case, they must be compatible with yellow metal. GL-5 and synthetics are generally not recommended.
I use 15-40 Rotella in the engine and CRC GL-4 85-90 in the rest of the driveline. I top off the t-case with CRC GL-4 140 when I need to add a little.

 

[Stan Leschert]

Get the TMs. Go to this site : MilitaryTrucks.ca - M37 Truck

 

[55CanuckM37]

Thanks everyone for the replies and pointing in the right direction!

 

[GUNNY 155]

Warren D pretty much nails it down. GL4 Type gear lube because it will not damage non ferrous metal parts. Engine oil needs to have a high zinc base for older type engines with flat tappets to prevent galling. I use Valvoline VR1 series racing oil but Shell Rotella is good too. DOT5 for the brake fluid. If not sure what fluid you currently have flush the system and refill. For Antifreeze I stayed with the good old green stuff. Though color is no longer a good indicator anymore. Cheers!

 

[pwrwagonfire]

I run 15w40 in my M-37...at work we have 3 power wagons (64s all of em), and we run only SAE 30 in them...however they get NO use during winter months.

We use 80w90 in the diffs, and DOT3 brake fluid

 

[808Morgan]

I've been using Archoil friction Modifier in place of zinc, it's better, check out the tests.

 

[hndrsonj]

I run 15w40 in my M-37...at work we have 3 power wagons (64s all of em), and we run only SAE 30 in them...however they get NO use during winter months.

We use 80w90 in the diffs, and DOT3 brake fluid

Same here.

 

[just me]

I run Rotella because I have it and use it in everything but my Alfa Multi-air. I run GL1 in the trans and axles and Lucas 50wt synthetic in the transfer case. When the new engine and trans are installed later this year I will put the Lucas in the new trans, also. GL1 is easily obtained from Tractor Supply as Ford Tractor Oil.

 

[Lumbar Jack]

Hi All,
I’m a newbie here, proud owner of a 1952 M37 bought from a fire department. Questions about engine oil:

1. Most who’ve posted here are using 15W-40. When I look up that oil, it’s always referred to as for DIESEL. Am I missing something?

2. For those using Rotella, does that mean Rotella T4 15W-40?

3. The original Army technical manual specifies engine oil as “OE 30”. Can anyone explain that designation?
Thanks!

 

[hndrsonj]

3. The original Army technical manual specifies engine oil as “OE 30”. Can anyone explain that designation?
Thanks!

It's just straight 30 weight.

 

[John Mc]

I'm using 10W-30 based on the technical manual's recommendation of 10 weight for the temperatures I see in the winter, and 30 weight for the temps I see the rest of the year.

I'm using a full synthetic which has zinc additives (Amsoil Z-rod 10W-30) specially for these older engines. Many modern oils do not have zinc due to its incompatibility with catalytic converters.

It's not cheap, but with their preferred customer discount, and buying a case of 12 at a time, it's not much different than other synthetics. (BTW - the myth of synthetics "causing" oil leaks is just that- a myth. Early in their Introduction, there were issues with synthetics Leaching various compounds from some seal materials. However, in order to meet current oil specs, synthetics include additives to prevent that now.)

I've had good luck with it so far.