Super AYC ??

[Adam.Findlay]

I may be getting my hands on a SAYC diff but I am oblivious on how to tell the difference between ayc and sayc without cracking open the diff, as I just wish to varify the product is what the seller says it is. Also has anyone cracked open a ayc diff, I want to cryo the gears before its goes into the ol' legnum. and once the diff is apart how dificult is it to put back together, as i have no idea about how to shim or preload a gearbox (imagine a complex diff like ayc requires the same kind of thing.)
One last thing due to the pressures involved in the clutch part of the diff is it safe for me to be even thinking of breaking the seals or is geting new gaskets/seals no problem?

All help much appreciated, Fingers crossed the diff is SAYC and i can get it cryo'd

[Wodjno]

Open up the inpection hatch

It should have 43 teeth on the crown wheel. Where as the VR4 has 53..

Just to add.. I have seen discussion on the site recently saying that S-AYC is on EVO's for EVO7 upwards ?

This is incorrect! S-AYC is from EVO8 onwards.

The Active Centre diff is used on the EVO's from EVO 7 onwards. This uses a different AYC pump that has an extra pipe and this runs the centre active diff.

Cheers

Wodj

PS.. Also unless your gonna be running silly BHP (400+) i wouldn't bother with the cryo. The EVO's run 400+ on the same diff.

[bradc]

43 teeth will just show you that it is an EVO 5-9 diff though. I'm not sure if there is a way to tell for sure externally. The guys on the lancer register would be your best bet though I think.

[Adam.Findlay]

PS.. Also unless your gonna be running silly BHP (400+) i wouldn't bother with the cryo. The EVO's run 400+ on the same diff.

Yip definatly aiming for 400+ (in the long run of course) and I know a dude who has broken SAYC on his legnum and hes running roughly 300hp at the wheels with just a plenum and few other things.
Yeah so has anyone opened up there diffs and or pulled all the gears out?

[VR-04-TT]

No gaskets in the diff. You need the right type of silicon to seal the casing back together and make sure it's absolutely spotless before you apply the sealant.

I haven't taken an AYC diff completely apart, but here's pics of what I have done. I hope they're of some help:

This is with the "squarer" side casing off (new diff):


This is the inside of that casing, the part at the bottom of the inside in this pic acts as a brake against the diff, changing the direction of the force. If you need to clean out this part, make SURE you use a compressed air cleaning tool to get right in behind this:


Closer look (this is the old busted diff, hence the gunk):


One output shaft and bearings removed (old diff):


Output shaft and bearings on their own (new diff):


I never took the other side off as I didn't need to.

Just make sure you clean those sealing surfaces really good before applying any sealant and you'll be fine. I spent about half an hour just cleaning those surfaces lol

I'm quite happy to pull my old diff right down if you need more pics. Just let me know.

[vr4-fan]

the S-ayc it for more power ,

[Turbo_Steve]

It doesn't GIVE you any more power, but it is less likely to break if you increase your engine power. The standard diffs seem a bit weak, especially if the fluid goes brown, they can break.

SAYC diffs are stronger, AND give you better cornering capability.

[vr4-fan]

It doesn't GIVE you any more power, but it is less likely to break if you increase your engine power. The standard diffs seem a bit weak, especially if the fluid goes brown, they can break.

SAYC diffs are stronger, AND give you better cornering capability.

that ist i mean , are more stronger , hold more power , you know my english not good

[Turbo_Steve]

I know dude. It wasn't a criticism: I was making sure.

[VR4WGN]

if you are purchasing a diff i recommend remove the opposite side of the diff to what VR4-04-TT said,by doing this you are able to inspect the diff wich i highly recommend doing.
things to look for are;
1-the colour of the oil
2- remove the crown and remove the taper bearing nd bush underneath it.
3=wipe the arwa clean round the centre bit where you removed the bush and look for very fine hairline cracks along it,this is the teller if the diff is any good.


now in saying that,it is proven that even if the diff has that crack it will STILL be a reliable diff,the only holdup is you should change the ayc fluids evrytime you do 5000-10000km or evry 6 months.

just a little bit of info forya

[VR-04-TT]

I'll disassemble the whole diff over the weekend, if I get time, and take lots of pictures so you can have illustrations for your post VR4WGN.

[VR4WGN]

lol sorry man,i know its a ramble i might actually dissasemble this stuffed 1 i have an load up an illustration briefing this week maby,and chuck it up in the resource library

[VR-04-TT]

haha all good I understood what you meant, I just thought others might not

Looks like a race to rip our diffs apart

[rees]

i aint rippin mine apart , havent even installed it yet !soon to be remedied by le nutter

[VR4WGN]

hahah youl lbeat me dude i got a gud ole power problem on my vr4 that needs a doctor first lol,i think Antone at Geartech actually has 1 of my ayc diffs apart,mite shoot and pic it up or do a breakdown there instead maby

[VR-04-TT]

I've gotta put my car back together first too lol

[VR4WGN]

ok looks like i have a headstart lol,iv dimantled and pictured the diff already and dismantled a 2.4 gdi lol,2 more gdi's to go and im all done .. ill do the article on the weekend guys,got some GREAT shots

[Adam.Findlay]

oh wicked that would be an awesome article. i have taken my diff apart but showing photos of a broken one wont be much help haha. but i did enjoy getting to understand the inneer workings of a ayc diff, (that sorta stuff facinates me)

[nads1978]

Holy thread revival Batman....

It doesn't GIVE you any more power, but it is less likely to break if you increase your engine power. The standard diffs seem a bit weak, especially if the fluid goes brown, they can break.

SAYC diffs are stronger, AND give you better cornering capability.

Correct, but more specifically; It's stronger, to allow a greater left/right torque split ratio, transferring 2 times the torque that was achievable with AYC. Hence the better cornering ability.

[Turbo_Steve]

I was trying to keep it simple!