Rear Differential - Internal Leak? HELP
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Rear Differential - Internal Leak? HELP
Hello,
2010 GSR - less than 80k Miles
I have a question,
Speculation is that my high pressure section of the rear diff is leaking into the clutch packs wet bath.
Current situation.. 4WD Light and leaking ATF from the passenger side breather..
BackStory: When the 4WD Light light popped up the reservoir was empty then i filled the AYC reservoir up and it kept disappearing with no visible leaks. Now, after a few "fill ups".. my rear diff is leaking from the passenger side breather. https://www.evoxforums.com/forums/sh...d.php?t=397806
My question to the evo gurus is... is that a reasonable assumption and if so.. how? also.. could a AYC pump failure cause this and why?
I cannot find any in-depth internal diagrams of the rear diff... why isn't this a thing or replacement parts... if anyone has access to it let me know.. i'd like to check it out..
Also posted this on the EvoxForums: https://www.evoxforums.com/forums/sh...d.php?t=398696
EDIT:
My AYC is throwing failure codes.
After spending a lot of time diving into what information i could find on the web about the AYC System is that.. the AYC system not only acts as a means to apply pressure onto the clutch packs to transfer power.. but it is also a way to remove heat from the front and rear differentials. Its is continuously running while the car is on and cycling fluid through the two differentials. If this pump were to fail and the flow in the system became stagnate then the rear differentials could overheat and cause damage/wear to the internal components of the differentials.
2010 GSR - less than 80k Miles
I have a question,
Speculation is that my high pressure section of the rear diff is leaking into the clutch packs wet bath.
Current situation.. 4WD Light and leaking ATF from the passenger side breather..
BackStory: When the 4WD Light light popped up the reservoir was empty then i filled the AYC reservoir up and it kept disappearing with no visible leaks. Now, after a few "fill ups".. my rear diff is leaking from the passenger side breather. https://www.evoxforums.com/forums/sh...d.php?t=397806
My question to the evo gurus is... is that a reasonable assumption and if so.. how? also.. could a AYC pump failure cause this and why?
I cannot find any in-depth internal diagrams of the rear diff... why isn't this a thing or replacement parts... if anyone has access to it let me know.. i'd like to check it out..
Also posted this on the EvoxForums: https://www.evoxforums.com/forums/sh...d.php?t=398696
EDIT:
My AYC is throwing failure codes.
After spending a lot of time diving into what information i could find on the web about the AYC System is that.. the AYC system not only acts as a means to apply pressure onto the clutch packs to transfer power.. but it is also a way to remove heat from the front and rear differentials. Its is continuously running while the car is on and cycling fluid through the two differentials. If this pump were to fail and the flow in the system became stagnate then the rear differentials could overheat and cause damage/wear to the internal components of the differentials.
Last edited by GundamX; Feb 1, 2019 at 09:38 AM.
#2
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It is a reasonable assumption. It's not a pump failure, a seal failed inside the diff. I'm not sure mitsu sells individual parts for the AYC rear diff.
#4
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You need to call the Evo drivetrain rebuilders and see what they can do. TRE, Shep, Jacks, etc. If the seals are leaking fluid into the fluid bath, its not going to build pressure, which will cause codes. It's apparent the clutch apply piston seals are leaking into the fluid bath because you're over flowing it. Your question has been answered, now you need to do some leg work to see if you can find parts..
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Thank you for the replies.
You reconfirmed my thought that it was leaking internally. Great. But, my main concern/question is... could the AYC cause this.. (see my edit above)
I have already emailed a shop about it.. waiting to hear back.
The reason i'm trying to dive into this is that... These seals don't seem to be a huge failure mode at all with evos as far as i can tell. When they fail... They either lock up or explode 99% of the time due to just harsh driving.
You reconfirmed my thought that it was leaking internally. Great. But, my main concern/question is... could the AYC cause this.. (see my edit above)
I have already emailed a shop about it.. waiting to hear back.
The reason i'm trying to dive into this is that... These seals don't seem to be a huge failure mode at all with evos as far as i can tell. When they fail... They either lock up or explode 99% of the time due to just harsh driving.
#6
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The pump not working will not cause this. The fluid bath is there to cool the clutches, and they make wayyyy more heat when the pump is applying them than if the pump is working. You have codes for the pump not holding pressure because the leaking seals aren't allowing it to build pressure. Fix the diff, and your codes will go away.
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Correct me if i am wrong... but, From my understanding of these types of systems.. There are a few reasons the clutches sit in a fluid bath.. not just for cooling..
1. Without a lubrication medium in-between the friction discs there would not be a smooth transfer of power along with increased wear due to binding.
2. Lubrication of the gears sets.
3. Cooling as the fluid will help transfer the heat to the exterior of the case.
The heat transfer through the fluid bath can only help so much. At a certain point the fluid will reach its limits.. and i believe they would have planned for this. Hence why the AYC pump is continuously running. Otherwise, why not just have it only activate when it is needed? Its has a accumulator to store pressure.
Take for example a automatic/dual clutch transmission. They have trans coolers from the factory to allow for heat dissipation as the wet bath alone is not enough in certain circumstances.
1. Without a lubrication medium in-between the friction discs there would not be a smooth transfer of power along with increased wear due to binding.
2. Lubrication of the gears sets.
3. Cooling as the fluid will help transfer the heat to the exterior of the case.
The heat transfer through the fluid bath can only help so much. At a certain point the fluid will reach its limits.. and i believe they would have planned for this. Hence why the AYC pump is continuously running. Otherwise, why not just have it only activate when it is needed? Its has a accumulator to store pressure.
Take for example a automatic/dual clutch transmission. They have trans coolers from the factory to allow for heat dissipation as the wet bath alone is not enough in certain circumstances.
Last edited by GundamX; Feb 3, 2019 at 09:33 PM.
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#8
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The fluid in the fluid bath is SEPARATE from the fluid that is pumped via the ACD/AYC pump. The lfuid from the pump only pushes on a piston which applies the clutches.
Yes the fluid bath is for cooling and lube. The fluid that is pumped via the pump is ONLY for the apply pistons. It has nothing to do with cooling the clutches and the pump does not run constantly, it runs when pressure is need to apply the clutches. The accumulator is there so there isn't a delay in apply pressure increase when the computer calls for it.
Your fluid bath is overflowing. This is because the fluid is leaking out of the pump system that applies the clutches. This is NOT supposed to happen. The fluid bath and the pump circuits are divorced, the fluid never intermingles. This causing the codes for lack of pressure in the AYC system because the leak is not allowing pressure to build..
Yes the fluid bath is for cooling and lube. The fluid that is pumped via the pump is ONLY for the apply pistons. It has nothing to do with cooling the clutches and the pump does not run constantly, it runs when pressure is need to apply the clutches. The accumulator is there so there isn't a delay in apply pressure increase when the computer calls for it.
Your fluid bath is overflowing. This is because the fluid is leaking out of the pump system that applies the clutches. This is NOT supposed to happen. The fluid bath and the pump circuits are divorced, the fluid never intermingles. This causing the codes for lack of pressure in the AYC system because the leak is not allowing pressure to build..
#9
We have a similar issue on a 2012 GSR up here in Canada, still not seeing AYC fluid overflow from the rear diff breather but this is on a low mileage car. Any one else experienced this issue?