What kind of oil is added to the transfer case?
3 Answers
The transfer case uses transmission oil. The transfer case is a device that distributes the engine's power, directing it to the rear axle or simultaneously to both the front and rear axles. It is a transmission component found in four-wheel-drive vehicles. The characteristics of the transfer case include: 1. Enhancing the vehicle's off-road capability; 2. High reliability; 3. Switching to two-wheel-drive mode on smooth roads can reduce fuel consumption. The working principle of the transfer case is: after the engine's power passes through the transmission, it is directly connected to the rear axle via the driveshaft. The transfer case then extends an additional output from the transmission and transfers power to the front axle's output shaft through a silent chain.
The transfer case on my Wrangler just had its oil changed recently. To be honest, transfer cases are even pickier about oil than engines – you've got to make sure it's GL-5 grade gear oil. My 2018 model uses 75W-140 full synthetic, and I specifically noticed the sulfur smell when pouring in that amber viscous fluid. For manual transmission models, it's best to use limited-slip formula oils like ZF MTF which works really well. But newer models like the Haval Dargo with on-demand 4WD actually require ATF transmission fluid instead. When removing the drain plug, I spotted shiny metal particles in the old oil – the mechanic said that's the early warning sign it's time for a change. After off-roading, oil temps can spike over 100°C, causing substandard oil to thin out and fail immediately. Once after charging through mud pits during rainy season, the transfer case started squeaking, but went completely silent after the oil change.
Last month at the repair shop, I witnessed the entire process of transfer case oil change. When the drain plug on the cast iron housing was unscrewed, the fluid came out like melted chocolate sauce. The key is matching the correct viscosity - an old Land Cruiser only needs 85W-90 mineral oil, while a Range Rover Sport requires 75W-85 full synthetic. The worst mistake is using wrong fluid type; there was a Pajero that accidentally got engine oil, making its limited-slip differential scream. I noticed mechanics always double-check fluid level with dipstick, saying even one extra drop could cause overheating. In Mohe where temperatures hit -30°C, they even switch to 70W oil, otherwise it'd turn to paste.