1946 super six 3 speed manual lubricant

engr1962

Hi everyone,

Just wondering what most people run in their manual transmissions?  90 weight Gear oil?  ATF?

/dan

Toddh

90w GL-1

Toddh

Also as I understand it, GL-4 attacks yellow metals but GL-1 thru GL-3 are good for our Hudson transmissions and rear axles. 

EP = Extreme Pressure:

Gear Oil Industry Specifications - API

GL is short for " GEAR LUBRICANT"

API has the following GL classifications: for Gear Oils - 

GL-1: Oil without EP additive.

GL-2: Usually contains fatty materials.

GL-3: Contains a mild EP additive.

GL-4: Equivalent to MIL-L-2105B and is usually satisfied by a 50% GL-5 additive level.

GL-5: Equivalent to MIL-PRF-2105E. Primary field service recommendation for Passenger cars and trucks worldwide.

GL-6: For severe service involving high offset hypoidgears. Often used to describe oils used in limited slipdifferentials. (Obsolete now)

MT-1: For non-synchronised manual transmissions in buses and trucks at a higher level than GL-4.

MIL-PRF-2105E: Designed by the US military, it takes conventional GL-5 and adds more demands to the specification. Most hypoid oils conform to this standard. Now superseded by SAE J2360 (2003).

35 Terraplane

Look up 

PENNGRADE 1® CLASSIC GL-4 GEAR OIL SAE 80W-90

Toddh

35 Terraplane said:

Look up 

PENNGRADE 1® CLASSIC GL-4 GEAR OIL SAE 80W-90

What’s the advantage of GL-4?

35 Terraplane

I looked into this a several years ago and per the Brad Penn which is now Penngrade data this classic GL-4 is designed to be used with yellow metals in manual transmissions.  At the time I searched for GL-3 but didn't find any.  Could be it's available now.