AYC Issue/Confusion

Rowie94

Hesitantly Boosting
Lifetime Member
Location
Warrnambool
First Name
Josh
Drive
2008 Toyota Aurion ZR6

1998 Mitsubishi Legnum VR4

Yamaha FZ6R
So, after my car came back from insurance repair, I noticed that the AYC was being very loud going around slow tight corners, like roundabouts. It seemed to squeak like a squidgee on a window on right hand turns, and creak and clunk on left hand turns. Using the guide here, I change the fluids inside the diff and AYC reservoir (GL5 and SP3 respectively) to see if it would make a difference.
Well, yes and no. At first, it still kept making exactly the same noises, and even going around a roundabout made the AYC gauge light up like a christmas tree.
Then the little red AYC light came on, my christmas tree went totally dark, and there were strange sounds no more.

What does this all mean? Did the diff realise that it was fucked so it just turned off the AYC system and is functioning as an open diff? And should I start looking for a new one?
 

LDundon

Violent Violet
Lifetime Member
Location
Orange
First Name
Lindsay
Drive
Pearl White 1998 PFL Legnum
Sounds like the pump is stuffed mate. Was it due to the service? Or just happened to happen at the same time? Did they service the rear diff for you? Maybe they used the wrong fluids? Possibly just by chance... it might mean the diff itself is stuffed, but sounds like just the pump.
 

Rowie94

Hesitantly Boosting
Lifetime Member
Location
Warrnambool
First Name
Josh
Drive
2008 Toyota Aurion ZR6

1998 Mitsubishi Legnum VR4

Yamaha FZ6R
Sounds like the pump is stuffed mate. Was it due to the service? Or just happened to happen at the same time? Did they service the rear diff for you? Maybe they used the wrong fluids? Possibly just by chance... it might mean the diff itself is stuffed, but sounds like just the pump.
It wasn't a service, it was an insurance repair from a failed theft attempt. They wouldn't have touched the diff. Fluids were changed by Sam before I bought it. Is the pump a big deal? Is it expensive or hard to change?
 

LDundon

Violent Violet
Lifetime Member
Location
Orange
First Name
Lindsay
Drive
Pearl White 1998 PFL Legnum
Pump isn’t to bad to replace from my understanding, although I am well known for preaching just putting an LSD rear diff in and getting rid of the AYC all together. I have an LSD and I prefer it to the AYC personally and means I don’t need the pump anymore
 

Rowie94

Hesitantly Boosting
Lifetime Member
Location
Warrnambool
First Name
Josh
Drive
2008 Toyota Aurion ZR6

1998 Mitsubishi Legnum VR4

Yamaha FZ6R
Pump isn’t to bad to replace from my understanding, although I am well known for preaching just putting an LSD rear diff in and getting rid of the AYC all together. I have an LSD and I prefer it to the AYC personally and means I don’t need the pump anymore
That's the direction I'm honestly considering. Just so I'd never need to worry about it again, and I am simply not an aggressive enough driver for AYC to make a difference for me. Do you have any pointers for finding a decent one?
 

LDundon

Violent Violet
Lifetime Member
Location
Orange
First Name
Lindsay
Drive
Pearl White 1998 PFL Legnum
If you’re not an aggressive driver you probably don’t want to go down the track of an LSD... as they’re honestly better suited at aggressive driving. plus there’s plenty of second hand AYC’s and pumps around.
 

Rowie94

Hesitantly Boosting
Lifetime Member
Location
Warrnambool
First Name
Josh
Drive
2008 Toyota Aurion ZR6

1998 Mitsubishi Legnum VR4

Yamaha FZ6R
It's more like... I'm sick of worrying about the diff. I feel like I would never worry about the LSD again.
 

naughtika

OzVR4 Stalker
Location
Brisbane, QLD
First Name
Christian
Drive
'96 Galant VR4, '17 MB A180, '25 Macan GTS
I suggest you get s-ayc or ayc from evo 7 or 8 ad they are much stronger than ours.

Also, from the pic you posted in the fb page, it needs a good servicing

Also open diff part uses GL-4 from memory and not gl-5 just in case this is what you used as replacement
 

Gav

1 AYC Bar
Lifetime Member
Location
Sydney
First Name
Gav
Drive
Galant
You want a sayc from the Evo 8-9 or go the lsd option.
You don’t want the Evo 7 diff
 

Rowie94

Hesitantly Boosting
Lifetime Member
Location
Warrnambool
First Name
Josh
Drive
2008 Toyota Aurion ZR6

1998 Mitsubishi Legnum VR4

Yamaha FZ6R
Also open diff part uses GL-4 from memory and not gl-5 just in case this is what you used as replacement

I hope it's GL5, because that's what I just put on it. 75-90 syntrax just like inn Macca's guide.

Screenshot_20180905-122142_Samsung Internet.jpg
 

TME_Steve

3 AYC Bars
Lifetime Member
Location
NSW
First Name
Steve
Drive
2010 nt did pajero tow car / 2000 6spd gc8 wrx tarmac rally car / 2000 Manual Subaru Outback 2.5 just a car
Evo 4-6.5 have the same ayc diff as vr4.
Evo 7 has a stronger version of that diff.
Evo 8-9 super ayc runs a torsen LSD in addition to the ayc clutch packs to increase torque transfer. They are stronger again in the housing and have the same stronger crown wheel and pinion.
Evo X is similar to 8/9 but will not fit a vr4 without a new centre despite a thread on here saying they 'machined' something inside the diff. They did not. They put a vr4 diff centre into the Evo X housing making it an ayc diff without the LSD of the Super. It would still be stronger than the regular ayc though. I know this as we just did one but we used an sayc diff centre from an Evo 9. Lucky I had one....
VR4s seem to eat rear diffs, far more than evo's, maybe the extra weight, maybe the open front diff means more torque goes to the rear, who knows. But in evo's, ayc are usually good for 250awkw, sayc mid 300kw at least, but there are also evo's running 10s with 500+kW and stock sayc diffs. We also have strengthening options for sayc....
As you all know I'm really a fan of sayc and ayc to a lesser extent. I feel that moving to open or viscous or plated LSD is a backward step and you lose something from the car. They do slide easier but then so do commodores
 

NSNO_RJB

No Idea what i'm doing
Premium Member
Location
Sydney
First Name
Ronan
Drive
1998 VR4 Galant
Just gonna bump this thread real quick

so if the 8/9 SAYC diffs run the LSD as well, would that mean if you put one in and dont hook up the AYC components it just acts as an standard LSD?

reason i ask is because i have an 8 SAYC sitting at home but an open diff Galant, i plan on getting a cheap / roller sunroof AYC model and swapping everything in. so id rather hang onto the SAYC diff if i can to save getting one in the future. So if i can use it now as an LSD i might as well do it rather than spend money on a magna LSD setup just to get rid of it a year or 2 down the track
 
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