Penrite Outback Hardened 4x4 75W-90 is a premium semi-synthetic gear oil formulated with an Outback Hardened additives package suitable for use in manual transmissions, transfer cases and transaxles that require API GL-5 and MT-1 specification fluids. Penrite Trans Gear 75W-90 is formulated with semi-synthetic base oils and Outback Hardened additives to provide excellent wear protection, extended service life and increased smooth shift performance. The oxidation stable formula will help to keep harmful deposits from forming and to assist in maintaining oil and component cleanliness. Trans Gear 75W-90 is also suitable for conventional differentials that recommend 80W-90 oils. To find the manual transmission or diff oil suggested for your vehicle; either add your vehicle to My Garage or check with your manufacturer, vehicle user manual, your local mechanic or head in-store and talk to one of our friendly team.