[fearitself165]

So for my first experience working with a automatic transmission was horrible. Now I'm back to tackle the job successfully. I have a 2011 bmw 335d 159k.

I have the steel oil pan currently installed which I believe is not supposed to be used with the zf 6hp28, and I believe the reason is it lowers the amount of fluid you can carry?

Now with that in mind, should I go for the uroparts aluminum pan for just a few (forty give or take) dollars more or just stay with the plastic.

When I had the valve body uncovered last because of extraneous circumstances I didn't have time to replace the valve body seals/mechatronic seal. How important is this to replace? I'm leaning towards doing it for sure but if anyone has experience I would love to know if it's worth the money/time for these extra parts.

When it comes to the fluid, what are the majority using? Mercon sp, Pentosin, HSS adrenaline, recline? Honestly when it comes down to it if there is a similar if not almost identical fluid for 5-10 bucks less a bottle I would have a hard time convincing myself to purchase lifeguard 6...

When doing a complete flush, as in I want to get all the fluid out of the torque converter as well, how many flushes and fills does this require and how many bottles can I get by with buying?

I'm thinking of replacing the transmission cooler/thermostat as well. Is this recommended or not worth the money? How about the lines and/or o-rings?

When you're looking for other upgrades to the zf 6hp28 transmission, is there a general order of importance of items to replace? Such as: Solenoids valve body, valve body separating plate (whatever its called), bushings, torque converter, zip kits/sonnax. I'm not exactly encountering any problems with the transmission as far as I can tell, but I would like to do as much preventative maintenance that makes sense.

Also I would like to get a transmission tune soon as well as a actual performance tune (Rollin with the emissions tune currently).

[whyzee125]

IMO, just use the plastic pan. It's what comes with the car and I've never once heard of one cracking unless it was hit on something.

I would use Mercon SP. Don't listen to people saying to run Valvoline Maxlife, Redline, etc. These transmissions do NOT shift the same with any other fluid and although the LG6 may be "nothing special" it's what the trans was designed to run with. Mercon SP is basically the same thing but made by Shell US instead of Shell Europe. I would not run any other fluid besides LG6 or Mercon SP.

I would do the mechatronic sleeve since it's easy and accessible and the most common part to leak. The bridge adapter inside also leaks fairly commonly so a good idea to do, but if you don't have time/courage to tackle that, I think you'll be fine. There should be no need for a zip kit, etc. unless you are experiencing symptoms. Keep that fluid clean and that's the best thing you can do for your trans, IMO.

[BB_cuda]

Agree with most of what whyzee said. I will say that the other seals are super easy. You have to drop the mechatronic unit to change the mechatronic connector in the back, anyway.

May as well do the others if you have the mechatronic down. The other seals are termed bridge adapter, and 4 cylindrical rubber tubes. They are simple. Changing the mechatronic connector takes a bit more skill. I would get a mechanics mirror and maybe take a picture of how the key way is oriented in the old one prior to pulling. Look at this orientation prior to putting new one back in.

I found it easier to be able to push/pry this guy back in using leverage via a pry bar. I used a small chunk of wood to not have metal bar directly against plastic connector shell. I found removing the transmission cross member to give me more room to do this prying. I put a jack under the very rear of the transmission to support while the cross member was out. Good luck.

P.S. I used mainly LG6 fluid but didn't have quite enough so i used about 1/2 L of the Mercon SP too. It takes about 7L of fluid if your dropping the mechatronic unit. I have wondered about changing the torque converter fluid out. I have read that the trans wants 9L of fluid if it were totally dry. I do find that hard to believe that torque converter would only use 2 L by itself.