The Ford Barn

rotorwrench · 11-02-2018, 08:47 AM

GL-5 can be used in rear axles with no problems. As I mentioned before, SAE-50, 100-grade ashless dispersant aircraft motor oil (with no Lycoming additives) is the same viscosity as SAE-90 gear oil. It is more highly refined than GL-1 and will not hurt any phosphor bronze bushings in transmissions. I've gone to a lot of airports around the country to purchase it for my motorcycles when traveling that way and have never had a problem finding it. SAE-140 is kind of heavy for transmissions and may cause shifting problems and especially in cold weather. If a person uses SAE-140 in a transmission due to leaks, they should fix the leaks.

I prefer AeroShell W100 but AeroShell 100 straight mineral can also be used. I use this in my 51 Mercury car transmissions with electric overdrive and it works well.

11-02-2018, 08:47 AM	#19
rotorwrench Senior Member Join Date: Jun 2010 Location: San Antonio, Texas Posts: 17,410	Re: GL 1 tranny oil GL-5 can be used in rear axles with no problems. As I mentioned before, SAE-50, 100-grade ashless dispersant aircraft motor oil (with no Lycoming additives) is the same viscosity as SAE-90 gear oil. It is more highly refined than GL-1 and will not hurt any phosphor bronze bushings in transmissions. I've gone to a lot of airports around the country to purchase it for my motorcycles when traveling that way and have never had a problem finding it. SAE-140 is kind of heavy for transmissions and may cause shifting problems and especially in cold weather. If a person uses SAE-140 in a transmission due to leaks, they should fix the leaks. I prefer AeroShell W100 but AeroShell 100 straight mineral can also be used. I use this in my 51 Mercury car transmissions with electric overdrive and it works well. Last edited by rotorwrench; 11-02-2018 at 08:53 AM.