Aug 15, 2007 · * API Categories GL-1, GL-2, GL-3 and GL-6 were declared inactive by SAE Technical Committee 3 in 1995, even though oils may be marketed with these designations. …

Feb 11, 2010 · The API (American Petroleum Institutes) GL-1 service designation denotes a lubricant that is intended for manual transmissions operating under such mild conditions that …

Jan 20, 2005 · GL-1 vs GL-4/other I seriously want to apologize if this has been covered already; I did not read all threads dealing with this issue. But I am referring to LO 9-2320-209-12-1, …

Feb 11, 2010 · GL-1 is a light duty oil made for light duty gearboxes without synchronizers. You will not find much GL-1 around my part of the country. In fact it is getting down right difficult to …

May 13, 2008 · GL4 is the "official" replacement for GL-1 (did not have as much of the high-pressure additives at GL-5, which caused the yellow-metal incompatibility). GL-5 with MT-1 …

Jun 15, 2012 · 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 …

Mar 29, 2013 · For GL-1 head over to tractor supply 17.00 for 2 gallon jug, I am still concerned about using the newer lubes in the older transmissions and transfer cases, as they were …

Sep 16, 2009 · I went over and 'prepped' my deuce I recovered in San Antonio two weeks ago; I added Valvoline GL-5 gear oil, which was rated MT-1. I just kind of topped off all of the …

Feb 8, 2009 · Use GL-1 or GL-5 with Yellow Metal Compatability. Napa sells it in 5 gallon pails. Same oil for the axles and transfer case too. If you pick GL-5 make sure it is good for yellow …

Nov 2, 2007 · GL-1 itself does not seem to have the chemicals in it that attack the M35 transmission and transfers and so would be inherently MT-1. I believe important thing is to …