Mitsubishi Lancer Evolution Forum banner

1 - 20 of 20 Posts

·
[E-Tuner]
Joined
·
15,860 Posts
Discussion Starter #1 (Edited)
In this thread, I will show you what you need to remove in order to swap over to a LSD rear diff (like the Cusco RS) and remove the AYC crap since you dont need it anymore. In removing the AYC stuff from the rear diff, you remove 18 pounds of rotating mass from the rear of the car while making your car handle better, IMO.

Drain the fluids out of the rear diff and disconnect the AYC lines. Drop your rear diff. Its not hard, just have a friend or floor jack underneath it so you can lower it down slowly. While you are lowering the diff, you need to pop the axles out. A crowbar works really well for me, just make sure you dont try to pry out the axles by the axle seals.

Once you get it all apart, pop off the gear side of the diff, remove the old open diff, press on the new bearings onto the LSD, and put it into its new home. Get the gear side cover, clean the mating surfaces, apply sealant, and torque the bolts properly.

Now pop out the half shaft on the AYC side, then remove the AYC side cover. The nice thing is that you can just let shit drop and damn near everything in that side is not needed. Get a bin or something to put all the AYC crap into, but you want to keep out this part (pictured below). It is needed for the half-shaft. After you remove everything, give all the covers and the AYC side of the diff housing a good cleaning.



Get your half shaft and the part I pictured earlier, and assemble them like pictured below. You will know when they are at the right spacing because the C-clip will snap into the internal groove of the part. Once they are snapped together, they are very hard to get apart.




Now you can start reassembling the diff by putting the first plate in place (after you apply sealant to both mating surfaces, unless you like leaks). Now you will put the half shaft in place like pictured below. Then apply sealant to the cover and slide it over the half shaft/bearing making sure the surfaces line up correctly. You dont want to hammer it in place, it should slide on with relatively little force. Torque the bolts and install the diff back into your car.

Now that the AYC is gone, you dont need to put any Automatic transmission fluid in there, so I put 2 quarts of Redline 75w-110 gear fluid in the diff. If you don't do track days, you can run a little lighter weight gear oil.

To retain ACD and not throw any S-AWC codes, you can loop the AYC lines like so



More pics to come.

If you mess anything up during this process, I am not responsible.
 

·
Registered
Joined
·
1,003 Posts
18 lb weight reduction? hmmmm i wonder how that compares to the 8/9 diff conversion. How much did the stock x diff weigh on its own.
 

·
Registered
Joined
·
1,139 Posts
No way the stock X rear diff weighs 80 lbs. If I had to guess its probably between 50-60
 

·
Registered
Joined
·
3 Posts
In this thread, I will show you what you need to remove in order to swap over to a LSD rear diff (like the Cusco RS) and remove the AYC crap since you dont need it anymore. In removing the AYC stuff from the rear diff, you remove 18 pounds of rotating mass from the rear of the car while making your car handle better, IMO.

Drain the fluids out of the rear diff and disconnect the AYC lines. Drop your rear diff. Its not hard, just have a friend or floor jack underneath it so you can lower it down slowly. While you are lowering the diff, you need to pop the axles out. A crowbar works really well for me, just make sure you dont try to pry out the axles by the axle seals.

Once you get it all apart, pop off the gear side of the diff, remove the old open diff, press on the new bearings onto the LSD, and put it into its new home. Get the gear side cover, clean the mating surfaces, apply sealant, and torque the bolts properly.

Now pop out the half shaft on the AYC side, then remove the AYC side cover. The nice thing is that you can just let shit drop and damn near everything in that side is not needed. Get a bin or something to put all the AYC crap into, but you want to keep out this part (pictured below). It is needed for the half-shaft. After you remove everything, give all the covers and the AYC side of the diff housing a good cleaning.



Get your half shaft and the part I pictured earlier, and assemble them like pictured below. You will know when they are at the right spacing because the C-clip will snap into the internal groove of the part. Once they are snapped together, they are very hard to get apart.




Now you can start reassembling the diff by putting the first plate in place (after you apply sealant to both mating surfaces, unless you like leaks). Now you will put the half shaft in place like pictured below. Then apply sealant to the cover and slide it over the half shaft/bearing making sure the surfaces line up correctly. You dont want to hammer it in place, it should slide on with relatively little force. Torque the bolts and install the diff back into your car.

Now that the AYC is gone, you dont need to put any Automatic transmission fluid in there, so I put 2 quarts of Redline 75w-110 gear fluid in the diff. If you don't do track days, you can run a little lighter weight gear oil.

To retain ACD and not throw any S-AWC codes, you can loop the AYC lines like so



More pics to come.

If you mess anything up during this process, I am not responsible.
Do you need the AYC pump working properly to retain the ACD?
 

·
Registered
Joined
·
706 Posts
How long ago did you do this?
I just had a problem with my ayc and found out the hard way how all the gears go back together. Would been nice to just delete all that crap as i dont use it anway it all gets turned off once i get into the car !!!!
 

·
[E-Tuner]
Joined
·
15,860 Posts
Discussion Starter #9
Do you need the AYC pump working properly to retain the ACD?
Yes

How long ago did you do this?
I just had a problem with my ayc and found out the hard way how all the gears go back together. Would been nice to just delete all that crap as i dont use it anway it all gets turned off once i get into the car !!!!
I did it last year, but I only ran it for a very short period because I switched to a Evo 9 rear diff with a LSD
 

·
Registered
Joined
·
706 Posts
Yes



I did it last year, but I only ran it for a very short period because I switched to a Evo 9 rear diff with a LSD
ohh ok cool.
thats my next step is changing to evo 8 rear end.
whenever this one breaks.
 

·
Registered
Joined
·
1,003 Posts
Yes



I did it last year, but I only ran it for a very short period because I switched to a Evo 9 rear diff with a LSD
Question!!!

Evo X diff minus AYC stuff + axels VS. Evo 9 diff + axels. Your thoughts?

I also wonder if a ralliart diff weighes less than the 9 diff.... the ralliart looks like it has an AL cover... maybe? Then again, ralliart axels are .3 inches shorter so i'm not sure how that would work with the evo's wider track width.
 

·
[E-Tuner]
Joined
·
15,860 Posts
Discussion Starter #12
Question!!!

Evo X diff minus AYC stuff + axels VS. Evo 9 diff + axels. Your thoughts?

I also wonder if a ralliart diff weighes less than the 9 diff.... the ralliart looks like it has an AL cover... maybe? Then again, ralliart axels are .3 inches shorter so i'm not sure how that would work with the evo's wider track width.
The Ralliart diff (which is exactly the same as the Evo 9 rear diff, just a different rear cover) and axles are a lot lighter than the stock X rear diff.

The stock X rear diff is around 85 pounds, and the ralliart diff is 45 pounds. Even without the AYC stuff, the X rear diff is still 5-10 pounds heavier than the ralliart diff.
 

·
Registered
Joined
·
1,003 Posts
Looking more into this, the ralliart track width is .6 inches narrower than an X. Wouldn't that pose a problem for the ralliart axels?
 

·
[E-Tuner]
Joined
·
15,860 Posts
Discussion Starter #15
Looking more into this, the ralliart track width is .6 inches narrower than an X. Wouldn't that pose a problem for the ralliart axels?
It hasnt for me and 2 other cars I installed the ralliart diff/axles on.
 

·
Registered
Joined
·
1,003 Posts
Great! I think you had mentioned in another thread you need the rear diff bracket from a ralliart to fit on the X, is that true? Would you happen to have the pt #?
 

·
[E-Tuner]
Joined
·
15,860 Posts
Discussion Starter #17
Great! I think you had mentioned in another thread you need the rear diff bracket from a ralliart to fit on the X, is that true? Would you happen to have the pt #?
You only need the bracket if you are using a 8/9 rear diff
 

·
Registered
Joined
·
3 Posts
Question!!!

Evo X diff minus AYC stuff + axels VS. Evo 9 diff + axels. Your thoughts?

I also wonder if a ralliart diff weighes less than the 9 diff.... the ralliart looks like it has an AL cover... maybe? Then again, ralliart axels are .3 inches shorter so i'm not sure how that would work with the evo's wider track width.
The Ralliart diff (which is exactly the same as the Evo 9 rear diff, just a different rear cover) and axles are a lot lighter than the stock X rear diff.

The stock X rear diff is around 85 pounds, and the ralliart diff is 45 pounds. Even without the AYC stuff, the X rear diff is still 5-10 pounds heavier than the ralliart diff.
Which would you say is the stronger LSD (the Evo 10 or the Evo 9?)
 

·
Registered
Joined
·
3 Posts
Evo 8/9 by far
Would you mind if I ask you couple of questions?

So say I want to swap the rear diff with the Evo9 one, or the EVO X RS one:
1) When I loop the AYC lines, will I still have ABS?
2) Does it affect the ACD operation? Will it operate correctly?
3) Why looping instead of plugging those lines in the pump itself? Is it just easier that way, or if you plug, it won't work correctly?

I assume after this conversion you get the EVO similar to the RS version that only has ACD and rear mechanical diff?

That's what I want to do with my GSR.
 
1 - 20 of 20 Posts
Top