Gear oil

I was looking for a source of gear oil and came across this
MIL-L-2105 : Former specification equal to API GL-4 performance level.
MIL-L-2105 B : Mono-grade automotive gear oil equal to API GL-4 performance level.
MIL-L-2105 C : Multi-grade automotive gear oil equal to API GL-4 performance level.
MIL-L-2105 D : Multi-grade automotive gear oil and heavy duty closed gear oil equal to API GL-4 performance level.
MIL-PRF-2105 E : Applied in 1995 in place of MIL-L-2105 D, after oxidation test, piston cleaning and thermal stability CRC L-60-1, Mack Cycling test, API MT-1 contra test.

API GL-1 : Non-additive lubricant oil for mid level service conditions spiral-bevel, spiral, chronic endless gear type differential and some plate gearboxes.
API GL-2: Special additive for gear type differential if API GL-1 not sufficient.
API GL-3: Special additive for plate gearboxes and conic spiral type differentials working under mid service conditions.
API GL-4: Hypoid gear oil working under heavy duty conditions that has no shocking burden.
API GL 5 : Hypoid gear oil working under heavy duty conditions that has shocking burden.

US Military, MIL-L-2105 C and D, 75W.
US Military, MIL-L-2105 E 80W90

seems the gear oil in a deuce is GL-4 not GL-1(per GO 80/90 Lubricating oil, gear, multipurpose MIL-L-2105 SAE 80W90) thought everyone might want to know.

bump so every one can see.

interesting. I made a stop in at Memphis equipment about 2 weeks ago and asked them what they install in all their rebuilt trucks. he said std GL5 goes in everything they do. transmissions and axles. makes me wanna change out my GL1 goop for GL5 synthetic.

Wish I'd known you were in town - I'm about 20 minutes from Memphis Equipment.

David, seems that you're never in town. LOL

Kenny,
You gotta point there!

DD

Caution: the extreme pressure additives of some GL5 gear oils can be corrosive to brass and bronze used in syncros and bushings. I always used GL4 dino oil in my Mog tranny for that reason. Everything else got GL5. I read somewhere that GL5 oils can cut a brass synchro's life in half. Now, GL5 synthetics are better about not eating your synchros. They usually are corrosive, but at higher temps than dino oils with EP additives. 300-350 deg syn vs. 200-250 dino with EP add.

Delo Gear Lubricant ESI is ok with yellow metals I called tech support to check if I remember right valvoline gear oil is ok too,
the military use's castrol I'm waiting to hear back from them.

I thought any of the oils with the API rating were yellow metal friendly?
James G.

I just noticed this Google add at the top of the SS page. They are are supplier of Mil Spec Oils.http://qclubricants.com/index.htm

If you use a GL5 in an application where you are concerned about yellow metal, make sure that your GL5 is also rated MT1... The MT1 suplemental rating shows that it is yellow metal "friendly". Not all GL5 is, and if it is not marked, you have no way of knowing if it is or isn't.

I have a post floating around somewhere here or on the www.g741.org site concerning the differences in the API GL ratings and how the MT portion fits in. FWIW, I can get single weight GL1 and multiweight GL5/MT1 at my local agri-supply right off the shelf, but I have to special order anything else...

CASTROL AP GEAR LUBRICANT
is a API MT-1 still have not heard back from the company on if it's safe.

After calling speaking with the chief chemist of Warren oil company, a Mr. Gary Whiteside, I am informed that the Warren 80W90 and 85W140 GL-5 do meet or exceed the MIL-L-2105 specification (superseding the spec) called for in the LO as well as having the correct "MT-1" formulation to prevent the corrosion of yellow metals (brass and bronze). Mr. Whiteside assured me that the oil is safe for use in the transmission and tranfer case.

that was sept. 2006, and 3000 miles later no issues, transmission shifts very smoothly and easily, much better than with GL-1.

Now only if I knew who would sell it locally, Tractor supply?