The Ford Barn - View Single Post

JSeery · 08-04-2020, 04:33 PM

[QUOTE=looking for GL4 140wt trans gear oil and found Valvoline 75W-140. label said its GL4 but worried about leaking, found Sta-lube 140wt on Amazon but trying to get local. Thanks in advance for the help and suggestions.[/QUOTE]

It depends on the driving conditions. If you are only going to drive it in hot weather, then 140 SAE viscosity would be ok. But in cooler / cold weather you would want the 75W. That is what is nice about the multi-viscosity, will work under both conditions. If you end up getting excessive leakage you would be better off address those issues.

08-04-2020, 04:33 PM	#3
JSeery Member Emeritus Join Date: Nov 2012 Location: Wichita KS Posts: 16,132	Re: Motor and trans installed today [QUOTE=looking for GL4 140wt trans gear oil and found Valvoline 75W-140. label said its GL4 but worried about leaking, found Sta-lube 140wt on Amazon but trying to get local. Thanks in advance for the help and suggestions.[/QUOTE] It depends on the driving conditions. If you are only going to drive it in hot weather, then 140 SAE viscosity would be ok. But in cooler / cold weather you would want the 75W. That is what is nice about the multi-viscosity, will work under both conditions. If you end up getting excessive leakage you would be better off address those issues.