DSM, 3S and EVO transmissions require 2.5-3 quarts of oil. For our DSM transmission rebuilds we recommend factory Mitsubishi 6-speed manual transmission gear oil from the 2005 Mitsubishi EVO MR. This is the best oil to use as it has the perfect blend of friction modifiers to keep the tranny shifting smoothly and prevent gear failure. Gear oil choice is very important and varies based on preloads and synchro blocker ring design, therefore it is strongly recommended that you stick with this fluid for our transmissions. If you are unable to locate Mitsubishi MR 6-speed oil from the Mitsubishi dealer, Redline MT90 gear oil will also work just as well. You can find this fluid here on our website.

For transfer cases and rear ends:

DSM:

• Use Redline Lightweight Shockproof in t-case and rear diff. If you have an EVOIII rear diff, do NOT use Shockproof as the LSD will not work with it.

EVO 8-10:

• For the t-case, the recommended fluid for stock to mid horsepower level street cars is the OEM DIAQUEEN Mitsubishi part# 3775610. For high horsepower and/or drag use, we recommend running Redline Heavyweight ShockProof(Red).
• For the rear diff, we recommend the factory Mitsubishi rear diff oil as the LSD clutch packs will no longer work correctly if you use Shockproof.

Transmission, ALL Mitsubishi:

DO NOT use Synchromesh, BG Synchroshift I or II, or Royal Purple. These fluids will destroy synchros and gears and void your warranty!
Shockproof in trans:

Absolutely DO NOT use Redline Shockproof in your transmission!

Shockproof is designed for ring and pinions found in t-cases and rear diffs, if you use it in your trans, you will break gears and ruin your synchros!
The pic below is of an EVOIII 1st gear which only had 6 months of use with Shockproof oil. Shockproof causes odd gear failures like this one where 1 tooth in your 1st or 2nd gear will end up breaking off and missing. We have seen a bad rash of odd failures like this with Shockproof users.


Shockproof can also cause fretting with gear teeth in your trans. Here is a picture of an EVO 9 1st gear and input shaft after using Shockproof:

How that customers gear didn't break is amazing!
Shockproof also has no friction modifiers, which means that synchros will be unable to work correctly and will have to work serious over-time in order to synchronize your trans correctly. Synchros need friction in order to properly operate. When there is no friction, they are under a large amount of pressure and will wear out very quickly. They will also feel notchy and unpleasant to shift.

The wax found in Shockproof oils will also plug up your small oil passages found in the synchros, shafts and center diff in your trans. Just please don't use it!
Shockproof oils are an unbelievable achievement in engineering and a miracle oil, but only if used as intended. Use Shockproof in your t-case and you will never have to worry about worn ring and pinions again. Use it in your trans, and you'd be lucky to get 6 months out of it. It is clearly stated on Redlines instructions to NOT use Shockproof in your trans. Take their word for it, they are the people who engineered it and know best.

Take our word for it, use the factory Mits oil in your trans at any HP level! We don't see gear failures like this when people stick to the factory fluid. Yes, we know, many people believe that you must have some kind of aftermarket oil for your trans if you are to push a lot of power through it. The Mits trans fluid is pretty amazing and will give you the cleanest gear wear, and shift possible.
It's hard to believe that oil from the factory is best, but it is and the reason why is due to the poor engineering of the EVO 6-speed trans found in the 9 MR. The trans broke synchros and gears at factory HP levels. Mits had this fluid developed to allow that horrid trans to survive. Due to this, it is the best trans fluid on the market today!

Next question we always get is: Can I use a mix of Shockproof or some other aftermarket oils with the factory fluid? The answer is NO! Please get away from the mentality that you must have some kind of aftermarket fluid in your trans! Use 100% Mits fluid mixed with nothing but more 100% Mits fluid. It works great as it is and will give you the best life and performance possible.
We don't know who has been starting the rash of Shockproof in your trans or mixed with other fluids as a good thing, because it's not. Please don't do it!

 

Bummer, no wonder I have gear lock IN issues..been using Redline for quite a while..55k miles.

 

I'm at a loss... Ya'll built my trans and i have ran stock fluid since up until i had shep rebuild my tcase and rear diff. When i asked shep what i should run they said mt-90 with 1 qt of lightweight shockproof... I literally have 30 miles since i put it in since my turbo blew the day i reinstalled the two and is still out, so i have no frame of reference for saying if the redline causes any issues. I trust both companies since you are nationally/internationally respected experts. So who do i follow? My warranty has expired i assume. Its been a year now since i installed the trans and i only have 3000 miles on it. Theoretically it shouldnt show any damage at this point since its primarially been highway/ breakin driving with no missed shift no gear grinds no racing to this point. When i drained the fluid last time i had metal slivers some nearly an inch long on the magnet. I dont know which way to go on this one.

 

^^^^^ agreed. I have talked to a very reputable person who said stock fluids except in rear diff run shockproof heavy.

 

I would never consider shock proof for the rear diff. Nor for my tcase. But I have the wavetrac diff in my tcase and they say don't. Only Orem diaqueen in both. I swapped to a different rear diff fluid and in three days burnt my bearing, Lucas oil if I'm not mistaken. That's what spurred my rebuilds.

The trams fluid is really blowing my mind and I would hope we could get a rep from Shepard in here to get their side of things.

 

I would follow the recommendations from the company which rebuilt your parts. If it breaks due to bad advise, then they can warranty it.

For our stuff, we recommend:

Trans- OEM Mits fluid or MR 6-speed fluid
T-case- Shockproof red or OEM
Rear diff- OEM

Joseph143, the shavings could have been from the front diff inside the t-case as the trans fluid is pumped through there. Did you send your t-case it to get rebuilt due to a failure?

 

So if you are unable to locate oem , what happened to using redline heavyweight shockproof 50/50 mixed with valvoline 80w-90?

 

In time your gears will look like the pictures above.

 

Great stuff! Thanks for the reminder!

What do you recommend for fluid change intervals for all 3 for DD? I only ask because a shop in Denver recommended every 5K miles for the transmission (he didn't mention transfer or rear).

 

Ok .....so your instruction you sent me were wrong then?

 

I would recommend:

Trans and t-case- 10-20k depending on if it's raced a lot
Rear diff- 20-40k

If you race the car heavily, then more frequent changes is best. If it is driven on the street and not raced much then less frequent is good.

 

How long ago was this? We used to have a mix in the instructions, but that was long ago. The new recommendations are in this thread as over time we found issues with Redline Shockproof used in the trans.

 

What's your opinion on RL MT-85 versus OEM and RL MT-90? IIRC RL is much cheaper, however, it's on once or twice a year expense.

 

The instructions were provided to me on 5/13/11, by Tim.

I have contacted your shop several times regarding my transmission not shifting. From your previous posts it would appear that your suggesting that the fluid (I was instructed to use) could be the problem.

1. I trailered my car to your shop to have my clutch adjusted to make sure it was adjusted properly before I drove it for fear of voiding my warranty.

2. Your shop (Jack himself) stated my clutch pedal assembly was supposably missing parts. In comparison to Mitsubishi's schematics and comparing to other Evos that I have worked on this is an incorrect statement as my car is not missing any parts.

3. I spoke with other shops who specialize in dealing with Evos or automotive repair and I have been advised that the only way the clutch/tranny would not shift is due to severe crank walk not motor vibration. I have the specifications showing that my motor was checked for crank walk. The spec range for my crank, from the shop that built it, stated it should be between .002 - .009. My crank tested at .005. Also, my motor was balanced to within a gram therefore there shouldn't be much, if any, vibration.

 

If you're in an area with cooler temps it wouldn't hurt to us the MT85. MT90 is what we normally recommend for anyone who wants to stick with fluid that will work year round.

We sell the Mits fluid for only $10.50 per quart.