Evo 3 ratio's

[ru16yt]

i have a evo 3 with whats meant to have a evo 2 rs "non lsd" gearbox. It has what we beleive is an aftermarket mechanical LSD in gearbox.

Rear diff was a plate LSD out of a evo also.

Transfer unknown. transfer locked up on me and we come to the conclusion some one may have fitted GSR ratio's to gearbox so we change the rear diff to gsr 3.545 ratio.

on dyno today the back wheels were going faster then front as shown on dyno so now im stumped.

Do i need to refit the evo lsd to rear and maybe its a wrong transfer case issue?

Any way i can count the front gearbox crown wheel while gearbox is still in car or some how work out the ratio?

Thanks for the help!

 

[4piknup]

Have a look on jackstransmissions.com there is a couple of vids to show you how to find transfer ratio and I think front diff ratios as well

 

[EVOCPE]

So you have a genuine EVO3??

EVO3 and EVO1 2 use different ratios in the box AND in the transfer case, which means if ur using an EVO1 2 box you need to use an EVO1 2 transfercase, if your using an EVO3 box you MUST use an EVO3 transfer case, and EVO3 transfer on an EVO 1 2 box will lock up

 

[EVO-00X]

Whats the gearbox code?
You could also remove the speedo drive off the top of the gearbox and pull it out to see what colour the small gear is. Should be pink if evo 3, tan if evo 1 or 2, or black if gsr. Thats a quick way to check without turning 10 times and counting rotations. Check the gbox code and colour of the speedo first then let us know.

 

[DOUGMO]

from that info i would guess you still had the evo 3 transfer with the evo 2 box.

 

[ru16yt]

Whats the gearbox code?
You could also remove the speedo drive off the top of the gearbox and pull it out to see what colour the small gear is. Should be pink if evo 3, tan if evo 1 or 2, or black if gsr. Thats a quick way to check without turning 10 times and counting rotations. Check the gbox code and colour of the speedo first then let us know.

Speedo drive looks tan not 100% though, Gearbox code as follows WPYE evo 2 RS Non lsd?

 

[ru16yt]

from that info i would guess you still had the evo 3 transfer with the evo 2 box.

So you think maybe refit the evo rear LSD to match gearbox and a gsr 1-2 transfer and i sould be spot on?

 

[DOUGMO]

Transfer case is easy enough to remove, take off the cover and count the teeth

I would start with that, guessing/assuming isn't working for you at the moment

 

[ru16yt]

Transfer case is easy enough to remove, take off the cover and count the teeth

I would start with that, guessing/assuming isn't working for you at the moment

Transfer in car now is GSR EVO 1-2 24teeth inside. Just removed it and checked.

So im guessing my nexted bet is to change the rear diff to a 3.909 LSD evo diff i have here?

 

[EVO-00X]

Yep. put the 3.909 rear diff in and it'll be sorted.
If it still locks up on you then theres a good possibility the front diff crownwheel has been swapped out for something else like an EVO 3 (63 teeth) or GSR (58 teeth).

 

[EVO-00X]

Oh, the speedo drives come in these colours so you cant confuse between them lol

 

[ru16yt]

cheers for all the help. I now have a "evo mechanical LSD in rear. When turning in either reverse or moving forward it does clunk a bit now? Is this normal for a mechanical LSD? Maybe aftermarket?

Also can i some how check now that all my ratios match?

Thanks guys!

 

[EVO-00X]

If it clunks its either damaged, got the wrong type of LSD oil in it, or its an aftermarket rear LSD.
Your main concern is the front diff crownwheel as its the only thing you havent physically counted the teeth on yet. Due to the gearbox code and the speedo gear colour both being EVO II, there's a good chance the crownwheel is still EVO II. No guarantees though unless you remove the gearbox to check. Then you can actually do it by opening it up (obviously) or moving the gear selector to a known gear, then turning the clutch disc and counting the number of turns the front diff pin spins (when you have a CV shaft removed and looking into the front diff). You could also mark a tooth on an LSD and count the spins. There's a bit of calculation to do with the ratios to figure out if you have 63 (EVO III) or 64 teeth (EVO II). I know someone who ran an EVO front diff ratio and a GSR rear diff ratio and the drivetrain locked up after a while at around 80-90kmh from memory.
Now that pretty much we believe you have EVO II ratios, put the car on a dyno and see how it drives at higher speeds. Double check the rear LSD and tooth count and show pics of the LSD if you have taken any thus far?

EVO I & II
Front Diff Ratio = 64 crownwheel / 15 output pinion = 4.266
Transfer ratio =24/22 = 1.09
Rear diff ratio = 43/11 = 3.909

EVO III
Front Diff Ratio = 63 crownwheel / 15 ouput pinion = 4.200
Transfer ratio = 29/27 = 1.074
Rear diff ratio = 43/11 = 3.909

GSR LANCER
Front Diff Ratio = 58 crownwheel / 15 ouput pinion = 3.866
Transfer ratio = 24/22 = 1.09
Rear diff ratio = 39/11 = 3.545

 

[DOUGMO]

standard lsds can clunk, it depends on the preload.
Mine is stock but has 50nm of prelod so clunks like a mofo lol, but it works well

 

[ru16yt]

It has redline oil in it? I buggered up and have the diff fitted already which if i thought i sould have counted the teeth as well as got pics! IM 95% sure its evo LSD though and is deff a plate type but unsure if standard or not. I guess this may another stab in the dark but can i some how confirm rear diff ratio while still in place? Also i did hear maybe you can count the teeth through the gearbox drain bung? Does this sound right?
Can i remove driveshaft to tell by rotations to check gearbox at all?

Alot questions and alot help, I do appricate all this guys! Please excuse my frustrations :/

 

[EVO-00X]

" Also i did hear maybe you can count the teeth through the gearbox drain bung?"
Nope. The drain bung is in the rear of the gearbox closest to the front of the car. The crownwheel is in the front bellhousing section of the case closest to the firewall. They are in opposite and diagonal ends of the gearbox to eachother and a whole heap of shit in between including another 2 case sections lol.
If you had some Mission Impossible hi-tech shit like a bendy mini camera with light hooked up to a laptop, you could remove the speedo drive, insert the camera and make it look left. IF you're lucky, and thats a big "IF" because the crownwheel teeth overlap the casing and could possibly be only viewed by a small portion if you slant your head, the wind chill factor is right and the moon, stars and sun come into alignment. Ive never tried it but hey, doesnt mean it cant be done, but i doubt it.

There is a 75% chance its an EVO rear diff ratio, 25% GSR ratio if you factor GSR vs EVO I/II/III. Im running an OEM EVO rear LSD inside a GSR rear diff houding and GSR crown and pinion. Again, iit could be EVO, it could have been modified like mine.

Anyhow, here's Jacks videos that will help explain how to check the gearbox ratio:
http://www.youtube.com/watch?v=GK6d-BFMW84

And transfer case ratio:

 

[EVO-00X]

And rear diff ratio:

 

[ru16yt]

So turns out the rear evo 3 rs lsd i was sold by mason autos is actaully a gsr rs lsd. Hence all these problems!

Will this have damaged either my rear diff or gearbox? Ive done around 100-140ks max.

I sould of counted the rear diff as well but when buying from a evo specislist i would thought be fine! Any how i shall change to evo 1-3 crown wheel now.

 

[EVO-00X]

If it didnt lock up, then all that would have suffered is the fluid and plates in the viscous coupling in the back of the gearbox. Remove the rear end case of the gearbox and inspect the VC for heat discolouration or splitting of the two welds along the side of it (give it a bit of a spin around to check all the way around it). If it shows either symptom, get rid of it and have it replaced.
Is the rear diff a viscous LSD centre? or are you sure its a plate type rear mech LSD from an EVO, but has had a GSR crownwheel and pinion in it?
If you want a rear mech LSD in an EVO ratio Im sure somebody here will swap you their mech LSD EVO unit for the mech LSD GSR ratio unit. Its only cost of postage rather than cost of swapping internals and then getting the backlash and tooth alignment done professionally.