T-Case Oil

89-94 DSM: The 89-99 DSMs used a spiral bevel gearset in the transfer case. The recommended oil for all transfer cases in the Mitsubishi DSMs GL-5 90w Hypoid gear oil.

>REDLINE SHOCKPROOF HEAVY If the vehicle is going to be drag raced Redline Shockproof Heavy is an excellent oil for the transfer case but make sure temps are 45*F or warmer because the oil is not thin enough for cold weather use.

OIL VISCOSITY INDEX CHART

96-10 EVO: The 96-2015 EVOs use a Hypoid ring & pinion gearset in the transfer case.  You must use only a GL-5 of higher oil in the transfer case. Mitsubishi recommends that the transfer case in the EVOLUTION be filled with their factory oil, Diaqueen LSD Gear Oil part#  MZ320345.

REDLINE 80W-140 GL-5 GEAR OIL  If the vehicle is going to be drag raced, road raced we recommend using Redline 80W-140 GL-5 Gear Oil. Their part number is # 58104. Do not use the “NS” version of this oil in the transfer case.

MOTUL GEAR Competition 75W-140  If the vehicle is going to be drag raced, road raced we recommend using MOTUL 75W-140 GL-5 Gear Oil. Their part number is # 101161.

REDLINE SHOCKPROOF HEAVY  If the vehicle is going to be drag raced Redline Shockproof Heavy is an excellent oil for the transfer case but outside temps should be 45*F or warmer because the oil is not thin enough for cold weather use.

OIL VISCOSITY INDEX CHART

You must use a hypoid type gear oil that is a GL-5 or higher in the transfer case.  It doesn’t take anymore than a drive around the block to cause irreversable damage so make sure you understand what oil go where. Do not mix oils. The old saying, “A chain is only as strong as its weakest link” holds true with oil as it only take a small amount of the wrong oil to ruin the film strength and you will sheer the oil film and you will ruin your gears.

When it comes to the transfer that is found in the Mitsubishi EVOLUTION, do not make the fatal mistake of using any oil that claims to be a magical GL-3/4/5 gear oil. One size fits all type oils are not recommended anymore than a one heat range fits all spark plug. These oils are notorious for ruining the ring & pinion gears in the EVO.

The transfer case in the EVOLUTION features hypoid gears; commonly referred to as ring & pinion gears, to transmit that power to the drive shaft. The word hypoid is short for hyperboloid which refers to the design of these gears. Hypoid gears don’t share a common axis, run quiet (for the most part) and they are very strong by design. Yet by this design, the gear teeth must slide across one another during their meshing and this is why you must use the correct gear oil with at least a GL-5 rating in the transfer case. Use the wrong oil and the transfer case and the ring & pinion gears will be ruined almost immediately from the intense heat that is generated.

Oil must be level with or slowly flow back out of fill/level plug.  Transfer cases that have the ACD fill rather slowly due to the fact that the oil has to flow through small passageways.  You will need to fill and check the oil level many times during the filling of the ACD transfer case. Chances are that when you think have an ACD transfer case filled with the correct amount of oil, it’ll still need a little more. Drive a short distance, around the block, and recheck the oil level.

EVOLUTION OWNERS TAKE NOTE: It is of utmost importance that the transfer oil be checked again after you have driven the car a few miles at speeds over 25mph to allow the oil to properly coat everything inside the transfer case, this is especially important when using REDLINE Shockproof in the transfer case. Drive a short distance and recheck the oil level.

EVOLUTION OWNERS TAKE NOTE: The Active Center Differential transfer cases require special attention during the filling with oil.  Due to the design of this transfer case the gear oil must travel through tiny passageways in the ACD clutch pack assembly before making its way to the ring & pinion. You must make sure to get the proper amount of oil in the transfer case or you will ruin it immediately.  Make sure to check the oil level several times during the filling procedure making certain that you have filled the transfer case to its full capacity. When you think that you have enough in there wait a couple minutes and recheck the oil level. If you try to rush this process, chances are that when you think have an ACD transfer case filled with the correct amount of oil, it’ll still need a little more. Ideally, you should be able to let the transfer case sit for at least 5 minutes and upon inspection of the oil level it should be full enough that the gear oil should drip back out of the inspect/fill hole.  When you are all done, drive a short distance, like around the block, and recheck the oil level. I know it sounds like a hassle but I’m trying to help you out here. If you run the transfer case low on oil you will ruin the ring & pinion gear.

Change the transfer case oil every 5k-10k miles.Vehicles that are being road raced require race car maintenance and all drivetrain oils should be inspected after each race and changed as needed.Road racing applications may add an additional 1/2 pint of oil to the transfer case for added lubrication and cooling. New or recently rebuilt transfer cases should have the oil changed after the initial first 500-1000 miles.