HybridKOOP

iTrader: (3)

Hey everyone,

I'm right in the middle of my clutch install... and have done some research on exactly what component needs fluids changed etc. in the drivetrain, and I see a bunch of conflicting information out there. I thought this might be a good place to have everyone post FACTUAL info all in one thread.

To start, obviously, the transmission uses Diaqueen transmission oil... about 2.5 quarts, and obviously needs no bleeding upon refill. For the EVO X, I know some people like AMSoil in the trans, but most seem to like the Redline MTL, and not the MTL/90 cocktail that was used on the EVO 8's and 9's. I'm going with 100% MTL in my transmission.

For the transfer case, most of what I read... people insist on keeping the Diaqueen in there and not to deviate from OEM fluid. This is the Diaqueen LSD oil, which is a 90 weight oil. It comes in a gallon metal container from the dealer for about $50, and is used in the transfer case and rear differential.

Here is where *I* personally am confused... Inside of the transfer case is our ACD. From what I understand, the ACD is in its own separate compartment and is SEALED off from the transfer case itself. I believe the ACD runs ATF in it.

The rear differential seems to be similar, in that it has a fill for the ATF, and a separate fill for "gear oil" which would be the Diaqueen LSD oil.

My question is really this... on the transfer case, are there two separate drain plugs? One for TC gear oil, another for the ACD? I want to make sure what I drained is the TC and not the ACD and not vice versa. Also, on the EVO X, there is a oil line that runs from the rear of the car to the front and attaches to the TC. I clamped this off when I removed my transmission/TC for my clutch install. Is this line running into the TC, or into the ACD compartment?

Then finally, the bleeding element of this all. When do you HAVE to bleed, and when do you not have to bleed... and are you bleeding the ACD only? Are the ACD and the rear AYC oil passages/resevoir tanks connected? Does anyone know how to bleed this stuff without the Mitsubishi MUT tool? Any insight and info shared would be greatly appreciated!

Lou

journeymansteve

There's a good maintenance schedule sticky -- check that for more details, but let me help answer a couple of your questions so you don't get confused when you print that out. BTW, print it, keep the schedule updated with what you do for it as an official maintenance record.

So there's nothing "called" a transfer case. In the front, you have the manual gearbox, it takes MT oil -- be careful not to put in wrong DOT spec because of the brass bushings. Use "MT" oil only. The other front item is the ACD. It takes Diaqueen straight 90 LSD (whale sperm anti chatter additive to the Mitsubishi spec ratio).

On the "bleeder" question the answer is "Don't touch it". If its low, fill it, but it's a PITA to get a scan tool out. It's brake fluid for the AYC. Since it's not used near brakes that get hot, that fluid has a VERY long lifetime, since you never ever need to open the top of the reservoir that could allow air into it. No heat, no air, that stuff has a long time before you want to mess with it.

Besides, in the rear, you have the torque transfer fluid you MUST change (ATF mercon/dexron iii) and the rear differential (more Diaqueen LSD). Plenty of fun! Takes a pump to get the stuff in the rear of the car pumped back in. The drain plugs are marked btw, and the fluid fills are on the same side as the fill plugs which help remind you where to drain and where to fill.

HybridKOOP

iTrader: (3)

Steve, thanks for the reply. I have a question for you. In the transfer case that that you're saying Mitsubishi refers to as the ACD only... are you really stating that this unit ONLY contains Diaqueen 90 weight oil? From what I understood, the transfer case houses the ACD in a separate compartment. If you recall, Edmunds broke the ACD in their car and "the fluids mixed between the two compartments". Your take on that?

Lou

oftheheavens

iTrader: (1)

Where is the schedule sticky you mentioned I have not seen it?

journeymansteve

I am so SORRY, they do call the ACD the "transfer case". Yes, Diaqueen LSD. I've been reading too many threads! The reason I had it confused is "of course only a Active Center *DIFFERENTIAL* will take limited slip differential oil" One and same. I hadn't heard of the Edmunds issue, so I'll look into it. There's a great tech video posted on You tube for the service training of dealers. Have you found that? It's actually 4 or 5 segments. So cool and informative.



It is in the Engine sub-thread: https://www.evolutionm.net/forums/ev...fications.html

https://www.evolutionm.net/forums/mi...ml#post6750417

journeymansteve

DOH, more bad terminology on my part. The ACD is the rear diff. The official mitsubishi stuff doesn't really call anything a "ACD" explicitly except in places like "capacities". Dumb as hell. The ACD and AYC somehow are same unit? At least according to one place in the manual. Anyway, the rear diff is where the ACD is, and it IS cool. Watch a video. Basically the car has "steering by wire" that shifts the ACD left and right based on your angle of attack.

robevo8

ACD= active center diff (up front with the front lsd, and in the transfer case connecting to the drive shaft going back {quite the piece if engineering if you can see a cross section})

AYC= active yaw control (in the rear diff, coupled with the lsd, thus sending torque left and right as needed {also i nice piece of work})

there are not in the same unit, ones up front, ones in the back

LaXGSR

To answer your question, you do have to go to the dealer when you're done to get the ACD/AYC bled. That's related to the one line you disconnected and clamped off during the clutch install. Only a dealer with a scan tool can do the bleeding effectively.

The only fluids you should have to replace after the clutch install are the transmission fluid for the transmission, and the LSD oil for the transfer case up front. Additionally, if your AYC/ACD fluid reservoir in the trunk is low after you're finished (because it leaked too much before you were able to clamp that line), then you should top it off with ATF fluid before going to the dealer for the bleeding.

Also, depending on how you did the install, you might need to top off the brake fluid and bleed the clutch (which shares the same reservoir as the brake fluid). I believe most people don't disconnect the clutch lines when doing the install though.

phemes

iTrader: (3)

That has to be the most confusing thread I have ever read on any forum :-)

journeymansteve

https://www.evolutionm.net/forums/mi...rvice-how.html

Read and learn the goofy terminology. Short story:

(Not including motor oil)
Up front - two fluids to change, one is LSD (get Mitsubishi brand) and one is gearbox manual tranny fluid

In back - two fluids to change, one is LSD (same stuff as up front) and the other is automatic transmission fluid, mercon III-dexron.

-->Also in the back of the vehicle is brake fluid; fill is on the right hand side of in the trunk. If that AYC thing with brake fluid ever has an issue, you have to refill it and bleed it with a special tool, a "scan tool". You DO NOT change it.

If you want more information, check out the fluid specifications sticky in the general area.

LaXGSR

Are you sure the reservoir in the trunk uses brake fluid? I was pretty certain it was ATF SP3 (reddish in color).

phemes

iTrader: (3)

If it's just for the control circuit why would you want to change it anyway ?

Ltdanish07

iTrader: (1)

There are too many damn threads going around providing so much different information.

I was told that the Trans, Transfercase and rear diff can all use the same stuff. I was going to put in Mobile 1 75w-90 ls in .Its supposedly good for limited slip applications.

So am i wrong in doing this? i already had the rear bleed by mits, all i have to do is the other fluids.

LaXGSR

Transmission and transfer case definitely do NOT use the same fluid. Transfer case uses LSD gear oil, and so does the rear diff. The transmission is the only piece that uses transmission fluid.

Scroll down to the end of the first post (last PDF image) for the official fluid types from the service manual:
https://www.evolutionm.net/forums/ev...fications.html

phemes

iTrader: (3)

So LaXGSR what is the difference between LSD gear oil and transmission fluid........errrr as long as you are talking manual gearbox its basically the same thing !! This seems to be the blind leading the blind.