So this damn car has become a personal project of mine working on it on my days off/free time. Replaced the thermostat and engine oil cooler which is now become a preventative job for the life of the car. I say that now because I was draining the transmission fluid and it came out chocolate milk!! Which tells me the transmission oil color was actually the thing that cause the chocolate milk in my cooling system. 😭 Picture of what came out will be attached.

So now my plan is to replace the transmission oil cooler, button everything back up and fill the fluids. Then during the coarse of maybe a few weeks do drain and fill jobs on the coolant system and transmission until it comes out clean. My question is- should I open the bottom of the transmission and replace the filter now or wait until the fluid comes out clean?

thanks mates!!

 

I would do it now to get as much of the chocolate milk out as possible. The "filter" is really more of a strainer so I don't think it will hold much fluid.

 

Replaced the transmission fluid cooler and filled it with atf. Also filled the coolant with coolant flush. I plan to drive a few hundred miles and drain and fill both fluids. Drove to work about 50 miles and there’s just a little bit of hard shifts but I expect that from a slightly contaminated transmission. Hopefully I can get rid of it after two or three flushes. 🤙 Also has a 3way pipe break on me and grabbed one from the auto store. I was surprised the way MINI had it installed with their system of plastic rings. Decided to enforce it with clamps.

 

UPDATE: car was running great up until last week, finally got around to pulling the transmission pan off. inspected the filter and there was some sand like material on the screen, so i think thats from the friction plates. at this point i feel like its going to slip in the coming future. should i attempt to rebuild the transmission or swap for a used one? i think my area has AISIN 6speed auto transmissions for 400-1200 depending on if they came from an S model or Justa and the miles from the wrecked donor. for the time being i am putting in a fresh filter and some Lucas stop leak to try and keep it from failing any sooner.

 

Picking up the conversation here since it's your OP.

After the work you did, is itnsafe to say you fixed the issue of oil-coolant mixing? Or is it still mixing?

You were looking to swap the transmission and we confirmed S and all4 transmissions are not the same.

If this were my project, i would replace just the torque converter OR send it to transmission shop to test it.

The slippage you felt might be from under/over filling.

 

Yes, there’s been no contamination between any of the fluids. The coolant level hasn’t moved at all. Only S All4 transmission I’ve seen in the area is 700. I might jump on it. Also I’ve gotten the P0753 after the transmission fluid has gotten warm.

 

Did you check car-part.com?

The shift solenoid might've gotten some particles in it and just need cleaning. You could buy another transmission and in the mean time you could try cleaning the vavle body.

There is a great video by a guy who goes through the process in great detail. Here is one of his videos
By the way, Mini and Vw transmissions are almost the same.

 

I was watching a few 09G repair videos and figured I’d pay a little extra to have a complete unit. I’ll try a free fix first with the Lucas oil and new filter. But was considering a new valve body but a used unit is cheaper. And good idea with trying to clean the valve body while waiting on the transmission!! I will definitely try that if the Lucas doesn’t work. Can’t break what’s already broken. 😅😅😅

 

Yes. That is from the clutches. If it were my car I'd get a good used auto trans just based on this.
Looks like you fixed the problem but still dealing with the aftermath.
I would do a "Mercedes Coolant System Citrus Flush" google it. The inside of your coolant system has that chocolate milk everywhere.

 

Finally had some free time this morning to test drive it safely. New filter and Lucas oil didn’t change anything. So I noticed that cold or warm there’s no 4th, 5th, 6th, even when manually shifting. So back to opening up the transmission and test a few things. Found this to tinker with, but it’s looking like I’ll probably end up swapping with a used S All4 tranny since the S ones are different. 😭

http://www.atraonline.com/gears/2008.../2008_8_30.pdf

 

Before that, did you check the fluid at the right level? putting back what came out isn't the right way to do it. It is a start but not proper.

 

I believe I did. I’ve done the procedure a few times but I can double check.

1. Level the car.
2. Pump fluid through drain hole with fill pipe until it pours out.
3. Let it pour out until it stops.
4. Start car and select gears for a few seconds each.
5. Refill and let it pour until it stops.
6. Start car until fluid dribbles out at 100f degrees.
7. Remove fill pipe and replace drain bolt and crush washer.

 

All steps are correct with thr exception the car nees to be running at all times.

 

i will redo it and report back!!