I have a 2013 R56 base model with an automatic transmission. after some trails to fill/drain ATF, the transmission is poorly catching to "D". My question is, Can I use a transmission off of an S model? assuming (correct me if i'm wrong) the S model automatic tranny is stronger and less prone to failure.

 

update...

I was able to temporarily use an 07 base model transmission. it worked fine for a week or 300 miles until i noticed coolant level getting low constantly. turned out to be the transmission oil cooler hoses were not clamping tightly since the junk yard guys cause some damage to the inlets.
Well, I used the cooler i had from the 2013 and it did not last a day. the tranny stared slipping. I put the original cooler back to no avail. the car is sleeping in the garage until i finish my next tranny overhaul/tear down.

 

2 hours of digging

 

What gears is it slipping in? I had a 3-4 flare and slipping in 5th and 6th. Turned out to be the k2 bonded piston. The base tranny looks similar if not exactly the same as an S.







Thats the K2 bonded piston. No clue what caused this to fail.

 

mine was actually not engaging and when i use the manual shift option and force it to m1, it would bang few times and shift to m5. I took the vavle body apart and it was dirty and some check vavles were stuck. I got it cleaned up and installed. Same thing happened. It wouldn't move. I removed the VB again and looked over the clutch packs. One set was moving while the other pack was not. According to the YT video i watched, that pack should be moving.
well, my 2013 transmission is finished and will be installing it over the weekend. Hopefully ut will work.

One more observation regarding the ATF cooler. Is the fluid supposed to flow out of it smoothly or is it a restricted flow cooler? In other words, i tried blowing air in it and it seemed clogged! Is that normal?

 

Hope it works out for you. I will check my cooler today when I get home and let you know. The new piston arrived today so I'll be putting everything back together this weekend.
I'm going off of YT videos and this manual:
https://www.scribd.com/doc/219057584...SN-09G-09M-pdf

 

Yep that is it...no snap ring at the first clutch pack though. I got worried when i started putting everything together. A guy on MA did a rebuilt and didnt seem to work for him! I'll stay positive. I will do another rebuilt to the one currently in and maybe make vids out of it.

 

final update...

i spent 12hr on sunday to do the swap. I didnt want to try my rebuilt and it wasnt ready. I used a 2007 base model transmission. Before going in, I replaced the ATF and filter. and oh boy the ATF was burned. so far so good

 

Update...after 750 miles of normal use, the transmission decided to quit on my way to work.

No gears whatsoever. no reverse no bangs no soul... I didnt want to investigate or waste time on it, So i went and got another transmission from a 2013...it is installed and running fine so far.

one thing to keep an eye on is the coolant. My fans start kicking after a little drive..