WOLF GUARDTECH 85W90 GL 4. It is a manual transmission oil with moderate characteristics of extreme pressure. It is specially developed to prevent corrosion of copper alloys. APPLICATION. It is suitable for lubrication of gearboxes with synchronizers, transfer cases, power steering mechanisms and most rear axles (certain rear axles require GL5 oils). FEATURES. Protection from wear: a long gearbox service life. PERFORMANCE. This oil comprises active components ensuring proper lubrication and long reliable service life. Approvals and specifications: API GL-4; MIL-L-2105