Hello, what kind of oil need the rear axle and the differential gear? It's a Chevy 3600 build 1953. Here are pics of the rear axle: Bilder | Unterrichts- und Übungsmaterialien Ask Wolfgang
From your book: 1954 Chevrolet Truck Shop Manual Using modern lubes, I'd us one marked GL-4. That way you could also use it in the transmission. GL-5 is OK for the rear end, but not for use in your transmission which had brass/bronze parts.
Start by reading this page which explains why you shouldn't use GL-5 in your gearbox: The difference between GL-4 and GL-5 explained - Rymax Lubricants Lubricants are much better today than in 1952 when these trucks were new. Specifications in 1952 called for "SAE 90 multipurpose gear lubricant" in the rear axle and transmission. A modern GL-4 lubricant rated at 80W-90 will do the job well.
