AYC clutch fluid change

[banjo]

The next job I'm getting done is to change AYC clutches fluid which I will be getting done by the workshop which repairs/services all our greys. Would appreciate any info, service sheet stuff anybody has. I believe it has to be bled properly and may require a special tool for this.

Thanks ladies and gents.

[Spirit]

I am pretty sure it is a main dealer only job. I paid around £50 when mine was done INSERT INTO post VALUES (part of other jobs aswell so not definate) but I do know they have to set the software back up afterwards.

Pete

[Rally205]

There are actually three different fluids in the AYC system. The mechanical differential uses normal gear oil and can be changed very easily as a DIY job.

The second is the AYC clutch fluid which is the special AYC fluid only available from MItsubishi dealers and can be changed as a DIY job if you can find a nice dealer who will sell it to you.

The third is the hydraulic actuator fluid which is Dexron 2 or ATF. This can be changed as a DIY job but it is much better to get it done by a Mitsubishi dealer as it does require bleeding sometimes. There are three solenoid valves and a pump and accumulator which can trap air bubbles and cause some funny noises when the AYC pump cuts in.

If your vehicle is an import it can be necessary for the Dealer to upgrade your ECU as there can be incompatibility problems with their MUT machine. In some cases it is impossible for their tester to communicate with some vehicles.

I would advise everyone to have their AYC fluids changed regularly especially the clutch fluid as it has been known for people to leave it an extra hundred miles or so and the diff has completely seized. It really needs changing every 4500 miles. It may sound like a very short interval but the clutch fluid is constantly under load even when the AYC lights are not lit.

[Rally205]

I forgot to mention that I once trusted a Mitsubishi dealer to change my AYC fluids and he used a substitute AYC fluid without informing me. This led to my diff being completely knackered 300 miles later. After having it replaced at my own expense I later found out from another dealer that the dealer in question had used non genuine fluid but too late to do anything about it.

So beware!!! Make sure they use the genuine stuff and talk to them about it and see if they know what they are talking about it.

[banjo]

Thanks for the info gents. Why the need to access the software? presumably at the ECU? Only the clutch fluid which has similar characteristics to auto-gearbox fluid is being changed. Can't see what electronic input/output from the ECU needs to be reset. I would have thought the yaw control has fixed in/outputs. What's a MUT?

Finally, one silly question, I thought all VR4's were greys. or not 'officially' imported. Mine was imported here new by the first owner, it's still grey though isn't it :confused:

[Brind]

Official means brought in by Ralliart.

Great info Rally205!

[Rally205]

The clutch fluid is very similar in appearance to Automatic Transmission Fluid INSERT INTO post VALUES ( ATF ) but it is most definitely is not the same. It must be AYC fluid which contains various friction additives.

The reason that they must access the ECU is so that the Multi Use Tester INSERT INTO post VALUES (MUT) or thing that they plug into your car to read fault codes if you like, can operate the AYC pump and solenoid valves in sequence to bleed out any air bubbles.

Brind is correct when he says that official cars were brought into the country by Ralliart and now by Mitsubishi themselves. These cars had their ECU's updated to be compatible with British MUT machines.They do not need to change inputs or outputs but all of the software so that your car speaks English instead of Japanese!

Hope this helps.

[banjo]

Yes great info Rally205, thanks very much again!
Since my last reply I found some info on the MLR FAQ's which gives a detailed description of the workings of the AYC for the EVO and now I comprendo, which I figure to be prob the same as ours. And the MUT device. Possibly what we need is to borrow this MUT and see if we can upload the software codes onto a laptop, can't be that difficult a code if just pump/valve sequencing, or from the ECU, Of course can only do that if car speaks English! ah! so! just a thought grasshopper!

[wirdy]

Fluid equivalents and spec HERE (http://www.lancerevoclub.com/evoclub-liquidi-e.htm)