RECOMMENDED OILS FOR THE MITSUBISHI TRANSFER CASE

89-94 DSM: The recommended oil for all transfer cases in the Mitsubishi DSMs GL-5 90w Hypoid gear oil. However, If the vehicle is going to be drag raced, road raced or being operated in climates that are 45*F or warmer we highly recommend using Redline Shockproof Heavy for it is an excellent oil for the transfer case. Also, you may use a GL-5 or higher Hypoid gear oil that has an ISO of 320-460 if temps are 45* or warmer because of the heat load that is generated is sufficient enough to thin the oil out so it doesn't aerate, web, foam up or cause lubrication issues due to the oil being too thick to perform properly. If do not have access to the recommended oils you can use any high quality straight GL-5 or higher Hypoid gear oil that is a straight 90 weight or an ISO index of at least 220.

OIL VISCOSITY INDEX CHART

96-07 EVO: Mitsubishi recommends that the transfer case in the EVOLUTION be filled with the factory oil, Diaqueen LSD Gear Oil part#  3775610 or a high quality GL-5or higher 90w Hypoid gear oil. If the vehicle is going to be drag raced, road raced or being operated in climates that are 45*F or warmer we highly recommend using Redline Shockproof Heavy in the transfer case for it is an excellent oil for the transfer case.

Also, if you are driving the vehicle aggressively you may use a GL-5 or higher Hypoid gear oil that has an ISO of 320-460 if temps are 45* or warmer because the heat load that is generated is sufficient enough to thin the oil out so it doesn't aerate, web, foam up or cause lubrication issues due to the oil being too thick to perform properly. These oils will offer added protection against metal on metal contact that can happen during high shock loads. If do not have access to the recommended oils you must use a high quality straight GL-5 or higher Hypoid gear oil that is a straight 90 weight or an ISO index of at least 220.

OIL VISCOSITY INDEX CHART

Do not use GL-3/4/5 gear oil in the transfer case

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 oils. These 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.

Hypoid ring & pinion gears

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.

Filling the transfer case

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.

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 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 has to travel through the clutch pack assembly before making its way to the ring & pinion and you must make sure to get the proper amount of oil in the transfer case.  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 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.

Change the transmission oil every 5000 miles. Vehicles that are being road raced require race car maintenance and all drivetrain oils should be inspected after each race and changed if the oil is dark or stinky. 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.

 © 2008 TRE