Is it wrong for me to assume the reason you can do this is because the ATF cannot go through the pump -> into the ACD side of the transfer case -> and leak into the transfer case itself, as is my situation now?
Also is it normal/right that since the transfer case is overfilled, it can leak more and more as time goes on? I would assume if it’s at 100% full, it would leak to 95-99% and stop leaking. Depending on if it’s parked level or on a grade. Why would it continue to leak ATF fluid now? How would it stop just by unplugging the ACD pump?

You are also correct, ATF is not corrosive to metal, that’s a sigh of relief at least.

 

Normally the fluid level in the transfer case is just to driveshaft level. What you have now is fluid right up to the top of the transfer box, breather level. So if you drive like that you will still have some fluid going out from the breather due to fluid expansion... Also, ATF is really not suited to the gear in the transfer..

ATF leaks now because the pump is higher than the transfer and it will go into the transfer as long as you have some ATF in the ACD pump. Even if you unplug the electrical connection you will have some gravity feed. I repeat, I presume that your seals on the ACD piston inside the transfer are worn... maybe even the clutch pack is worn and the piston is pushed out from its normal position as it has really short travel..

 

I understand - the ATF has been leaking out of the t case since the car has been parked. I let it leak out, and caught it with a pan (most of it when I noticed how much). Just from sitting the reservoir is now almost empty, I’m waiting for a tow now, and dropping it off this morning to the shop.
They will call later this week and let me know what the actual cause is and the fix. I will post all that after.
I drove it leaking (not as bad as it is now), it seemed to only leak while driving and when parked I got a few drops. But from sitting it leaked a lot more than a few drops. After smelling the gear oil and seeing the red ATF, I decided to park it until it’s towed. I’m sure driving it a short distance wouldn’t hurt ? But better to save the ring and pinion gears if I can.

My curiosity is getting the best of me, and when I have some down time I’d like to see a ACD pump apart. I told the shop to replace all the o rings and seals they encounter while taking it apart and they agreed now is a good time to do it.
Thank you for the explanations and help! Will post more information later in the week when I get it.

 

Transfer case was sent to Buschur Racing, just waiting for a response as to what was actually bad. Should know later next week.
They will inspect the clutch pack and see if it needs replaced. If not, it's likely ACD piston seals causing the leak. Hopefully there's no major damage.
Transfer case never made odd noises, so I'm assuming just seals, fingers crossed.

 

Got the car back tonight. It was just the ACD seals that went bad. Seals were replaced, and car now operates normally, and holds its fluid in! Now it just needs detailed again
Rest of the transfer case looked good, thankfully I stopped driving it and had it towed.

If anyone else is having a problem with your ACD reservoir going empty, and having to refill it, that was my problem. Hope this can help someone down the road.

Thanks everyone for input and teaching me something about the car, it is greatly appreciated!

 

Glad you got it all sorted out and thanks for updating the thread with the final results.

 

Just got my hands on a 2010 SE with a rebuilt jack trans.

I am having a very similar issue.

I’ll post any results and I work through this ordeal.

 

After reading this thread a few times lol. I am going to flush the TC and refill this weekend.

Also I will unplug the ayc. Does anyone have any tips or links on how to do this?

thank you!

 

regarding oil seals, TRE uses RTV so i do too. guaranteed no leaks

 

Evo 9?

 

No , this is for a Evo X SE I just picked up. I’ll try take pictures when I flush the TC this weekend. Just waiting on the Mitsu gear oil to reach.

awd service light is always on. So I believe the pump isn’t good as well