[Guest]

2 issues for your edification (or otherwise):-

AYC Fluid Change
My TME was in for service today. I spoke with mechanic who was dropping me off at work and he said that he had noted that the AYC fliud was always clear when you got it out by just draining out of the reservior. It was not until they put the MUT11 onto it and turned the steering wheel to pump out the AYC fluid that they saw the horrible black burnt fluid coming out. He reckoned that you'd be alright just draining it for a couple of times but that you should pump it out every 3rd/4th change. He also said they are still using the pucker mitsi AYC fluid as they have loads of it but will use Dexron 3 when they run out. Apparently when pumped out the fliud comes out very fast so make sure the drain hose is on tight!

Rear Suspension cracks
When i was at the rally prep place who did my decat the chap there had an E6 being prepared. He showed me how the rear upper suspension wishbone had cracked along the casting mark around one of the rubber bushes where they fix onto the strut. The chappy whose car it was didn't realise until the car was stripped down. As the crack is facing into the body of the car it would be very difficult to see when on the car. There is a 6 week delivery on these bits.

 

[Guest]

guys,

no one going to comment on the AYC fluid comments? I'm thinking about doing my own servicing and so am interested in whether the mechanic was talking ###### or not.

 

[Guest]

Mitsi will be changing the schedule soon to reflect what you have been told(draining the pump every 4th service), If serviced by mitsi they should always use the correct ayc fluid to preserve the warranty,
If you do it yourself, who cares!

 

[Guest]

I am confused (not difficult really ) I believe that the AYC fluid is currently changed every 4500 miles using the MUT11. If the really bad fluid only comes out when activating the pump, surely this needs to be done every time, not less often. What is the point just draining the good looking fluid and not the bad stuff?

 

[Guest]

Simon, Oli goon,

Please use the search facility to find any extra info you want as there has been many posts on the subject.

The AYC fluid does not need the MUT11 to change, only drain and refill. This is special AYC fluid.

The activation fluid in the reservoir in the boot needs a MUT11 to bleed the system after replacement. The MUT11 allows you to run the hydraulic pump and operate the directional control valve and so bleed both sides of the system. This is ATF (Automatic transmission fluid).

The AYC fluid is more important to change regularly as this is the fluid around the clutch plates in the AYC diff and so gets 'dirty' and if left would cause premature wear of the AYC diff.

 

[Guest]

Clive,

agreed me old fruit, but you don't address the main thrust of the question, unless i'm talkin out me bum (again). The mechanic was saying that you cannot totally drain the AYC fliud from around the clutch packs without a MUT11. He reckoned that the AYC needed to be activated to get rid of all the fluid. He did not mention the actuation fluid.

 

[Guest]

I am allso confused,
I thought that the fluid in the diff was more likely to get contamineted by the cluth plates than the fluid in the reservoir as there is a ally plate with oil seals between them and i fail to see how the mut can expell any badly contaminated fluid ie from the diff.

 

[Guest]

Clive

What I was implying is that the current service schedule is to fully drain the AYC fluid, I don't care how you do it, but you miss the whole point of my question. Irrespective of how you activate the AYC system, why would you change the service schedule for fully draining the system to a longer interval, when it appears to be the bit when you activate the system that gets out the fluid that is in the worst state. That does not make sense.

 

[Guest]

Oli, Simon,

Mechanics Quote;

he had noted that the AYC fliud was always clear when you got it out by just draining out of the reservior

The AYC fluid is in the AYC diff around the clutch packs and the speed increasing/decreasing gears, not the reservoir. ATF activation fluid is stored in the reservoir.

It was not until they put the MUT11 onto it and turned the steering wheel to pump out the AYC fluid that they saw the horrible black burnt fluid coming out

Apparently when pumped out the fluid comes out very fast so make sure the drain hose is on tight!

From these two statements I think you are getting confused between the AYC fluid and the Activation Fluid. The MUTII is used to run the hydraulic pump to drain or bleed the ATF ACTIVATION fluid. Their are two bleed nipples on the pump to which you connect a drain hose when emptying or bleeding the system. When the pump is running and the nipples are open fluid will be expelled quickly, which is what the mechanic said.

Running the pump with the MUTII will not pump AYC fluid from the AYC diff. This will drain the same as draining fluid from a gearbox. The AYC fluid just sits around the clutch pack and gears, lubricating them and when the drain plug is removed the fluid will come out.

Oli, your two posts seem to contradict each other, in the first he seems to be talking about the ATF fluid in the res in the boot, in the second about the AYC. It makes no sense to me to have to operate the clutch packs to drain all the fluid from the AYC diff.
The wet multi clutches that transfer the torque are similar to a wet clutch use on a motorbike. They are lightly touching together all the time and transfer torque when pressure is applied to press them together. They are pressed together hydraulically by the ATF activation fluid.

When the car is stationary at the time you are draining the AYC fluid, the pump is obviously not running and the clutch packs are just lightly pressed together. There will be no reason to operate the AYC, ie simulate torque transfer (pressure the clutch packs together) to drain any extra fluid from the diff.

But to drain all the ATF activation fluid you definately need to run the pump and so need the MUTII. (There is a way to do it without a MUTII, but it makes it easier)


Irrespective of how you activate the AYC system, why would you change the service schedule for fully draining the system to a longer interval, when it appears to be the bit when you activate the system that gets out the fluid that is in the worst state. That does not make sense.

Simon, to answer your question, the reason it makes no sense is because I'm pretty sure the mechanic is talking about the ATF activation fluid. I agree with the mechanic that the ATF activation fluid need only be pumped out every 3rd or 4th AYC fluid change. As this is only being used to activate the system it is not that critical if it gets a bit dirty the only problem being degredation of the hydraulic pump if there is air in the system.

Personally I think the service interval for the AYC fluid change is too regular and I have been replacing mine every 10000 miles and have experienced no problems.
Originally the service interval for the AYC fluid replacement was 28000miles, but on some earlier EVO's there was a problem with the software programming of the AYC ECU which caused premature wear of the clutch plates and lots of particles in the AYC fluid, so for a quick fix they changed the service interval for the AYC diff to 4500m and Mitsu garages also made more money.

The AYC ECU problem was sorted on later cars but they didn't change the service interval.

I hope this makes sense to you as I've typed it out after working a 12hr nightshift!

 

[Guest]

Thanks Clive, it makes a bit more sense now.

 

[Guest]

Thank god for that!!

 

[Guest]

Clive,
Excellent write up.
Maybe add it to HH6's faq that he's compiling.


Thanks for the info

 

[Guest]

Clive..........I'm not questioning your technical response ........all I will say is that my E6 GSR has only done 18K miles from new and has a full main dealer service history which includes all the AYC oil changes and the diff wines like a pig !

Mine is not the only E6 to have this fault...........either the diff is CRAP........or I've been charged for work which has'nt been done properly ???

Mind you I requested that they change the gearbox oil twice ( which they charged for ) , prior to a syncro fault on the gearbox at 17K miles , on draining the oil myself I cannot believe that it had been changed at the last service ( 14K )

I will never put my car into a main dealer again!!!!!!!!!!!!!!!!!!!!!!!!

CCC need to sort there act out , AS THEY ARE TOTALLY USELESS , I could list loads of problems with the quality of the service from my local main dealer.......but whats the point , I love the car so I'll put it down to experience !

 

[Guest]

Dave,

Sorry to hear about your problems, is it your rear diff that is whining? This does not sound like a problem with the AYC clutch packs but a bearing problem.

If the AYC oil is not replaced regularly enough this can cause premature wear of the clutch plates, but this will sound like a graunching noise when you turn a corner.

The other known problem is premature wear of the input shaft bearing of the gearbox caused by incorrect preloading of the bearing at manufacture, HH6 has all the info on this!

I also do not trust garages and have carried out all the maintanence on my Evo 6 since new.
The car has now done 32000 miles and the only fault is the above input shaft bearing failure.

I am also in the process of stripping the rear AYC diff ready to fit a CUSCO LSD and then junking the AYC part. As I do this I will take some photo's of the AYC mechanisms and e-mail them to anyone who is interested.

 

[Guest]

There is a common misunderstanding about how the AYC actually works and mainly with the different oils used (3) in the system, where they are used and when they should be changed. Clives info above should clear that up (well done for the typing ) however the service schedule does say the AYC diff and reservoir fluid should be changed every 4,500 miles. I don't think I have ever had my reservoir fluid (ATF) changed (haven't checked my invoices yet though) and to be honest it only needs to be changed every 27k miles or so. As Tony said there is a new schedule coming out which I believe will put the AYC fluid changes to 18k miles which seems more sensible. I will probably in future change the AYC fluid at 9k miles along with the other diff and gearbox oils, the reservoir ATF can stay at 18k miles.

Clive,
I would be very interested in how you get on with Cusco conversion. I understand there are actually 2 lines of Cusco AYC diff conversion kits which depends on the type of AYC diff you have fitted. Apparently there were 2 types of AYC diff fitted in the factory (earlier one more prone to failure?) and no one can tell what one you have fitted until it's stripped. Have you heard this?

 

[Guest]

I'm getting a bit confused here (especially with fluids in the rear).
Can someone make a recap of ALL the fluids in the transmission of our cars?

My mechanic has just replaced the gearbox, transfer and rear diff fluids with Castrol TAF-X. I will take the car to Mitsubishi to replace AYC fluid soon (the car already has 12kmiles). Have we done something wrong?

I haven't been able to test drive the car since the fluids were replaced, but I expect to drive it in a couple of days.

 

[Guest]

I strongly recommend Redline transmission oil's , it's the only stuff I'll use in my VI. The crap I've drained from various customers Evo's is staggering , very worryingly I have never seen wot I consider 2 b the correct grade in the transfer case. BTW I stock the various correct grades of Redline required 4 Evo's.

 

[Guest]

HH6,

Thanks I'm aware of the two AYC diffs fitted and will have to strip the diff and measure it before I order the CUSCO replacement!

 

[Guest]

clive,

good answer that. so basically the mechanic was being economical with the truth. This has put my mind at rest for doing the servicing myself.



HH6,

the 2 different AYC's fitted was presumably why when Claudius ordered a cusco rear diff he couldn't fit it coz he had the wrong one from cusco to match the one on his car? can you tell from the outside of the casing which has been fitted?

 

[Guest]

Clive, can you do a write up on your LSD when you fit it please? I heard that changing the front diff made the biggest difference and I'm curious as to what effect changing the rear one does for the car.