I had very big issues with my REVMAX valve body. I had 2 so I swapped in the other one adjusted it a few times, then I said, I am leaving it. I will say it is taking a long time to become perfect, but it is steadily marching to it. Just leave it and drive. It will learn. Keep in mind downshift clunks and momentary slips are normal through the process. I found if it gave me a double or triple downshift, everything would feel like crap for 3 days, then overnight it magically would be better than it was before. That is the game, continues to feel better, then 3 days of crap, then onward again. The amount the valve body is out of adjustment will decide on how long it will take. Just let it go, try to use driving conditions to you benefit. Stop and go traffic was very good for me.

 

I'd never have imagined it takes that long to learn. Is Revmax much cheaper or better than OEM/Aisin?

 

I'm not even going to tell you how long its been...its been a long time, but it is has been continuing to get better every day. Mine was probably way out of adjustment and it need to march in that direction for a long time.

 

Here’s a quick update on my situation. The hard shifts from 1st to 2nd and weak shifts from 2nd to 3rd never resolved themselves. I reached out to RevMax and they agreed to send me out another rebuilt valve body. I replaced everything one more time. After refilling, releveling, and resetting the adaptations once again using ISTA+, I was presented initially with a VERY smooth 1st to 2nd shift, and the 2nd the 3rd weak shift was also resolved. However, I had a new problem... 3rd to 4th (which was completely fine in the original VB and the 1st replacement) was now slipping quite a bit (around 600 RPM’s or so, maybe more). It got a little better after driving for 20 min or so, but not much. Then I remembered reading something on Sonnax’s site about how you can’t have any fault codes when going through the relearning process, as well as you have to have over 1/4 tank of gas I believe it was. I was almost on empty, so I pulled into a gas station and filled it up. IMMEDIATELY upon pulling out, the problem from 3rd to 4th was 100% gone. No slipping... not even once! So HUGE lesson learned and hopefully this will help someone out there. When you start the relearn process after resetting the adaptations, be sure you’re gas level is well over 1/4 tank!

It’s been a couple weeks since the 2nd VM was swapped and... wouldn’t you know... my daughter told me she’s experiencing more rough shifting from 1st to 2nd gear!!!!! AAAAHHHHHH!!!!!!!! She said she thought it was mostly when she started driving for the day, while the tranny fluid was not warmed up yet. I just took it out tonight and confirmed her beliefs. It’s not nearly as rough as with the 1st VB replacement from RevMax, but it’s still a bit choppy and bouncy from 1st to 2nd. However, after about 5 min of driving or so, it smoothed right out and I no longer felt anything rough once the tranny fluid was good and warm. Is this just something I’m going to have to live with?? Does anybody else experience any rough shifting at all while cold, which goes away once warmed up?

 

Did you try checking the fluid again. Maybe it needs another 4oz.

 

Good point. Maybe you're a tad low on fluid?

What does you gas tank level have to do with transmission shifts? That's very interesting.

Did you reach out to RevMx again?

I know it hurts after so much effort but I wouldn't live with it. I would ponder putting in a used trans. That's what I did at 150k on my 2008 R56.

 

I was going to test that out today. I made a sweet little device that allows me to pump tranny fluid up into the pan through the lookout, so at least that'll be easy. And monitoring the tranny fluid temp with ISTA+ is also a God-send!!! I highly recommend. Here's a link and screenshot to the Sonnax pdf about the relearn process:

https://d2q1ebiag300ih.cloudfront.ne...f?v=1534854454

 

I have my aisin 6 speed out of my 2006 r53. It's on the work bench with the case split. I plan to begin the rebuild process today. Any tips?

 

You should document it for us my man. Most shops will not rebuild it or they want $5000.

 

I know, old thread. I'm having an issue, loosing 4,5, 6 after car is warmed up. Installed several VB, with the last one from a very reputable builder, and same issue. Did reset at dealer, etc., etc, same problem.

I plan on going to the junkyard and getting a tranny as I'm tired of messing with valve bodies. Is there a DIY somewhere for swapping a tranny. I tried searching and only came up with manual transmissions

 

Sound like a twin problem...LOL...don't think I'll have it rebuilt at this point. Just going to roll the dice and swap it would a used one. Did you do the swap or a shop?

 

Not a club that I'd like to join, but here we are with a 08 MSC with no 4,5,6.

I messed with swapping a used valve body in and playing with the adjustments in both my new and old valve body to fix a shift flare from 3-4 but no luck. Swapped in a replacement solenoid for K2 and still no go. Here's my current thought... The car now has 170,000kms. I did the first ATF change at about 160,000. Oil was still dirty so I changed it again. After popping the valve body out, the majority of the dirty oil got swapped and I was happy with the color of the fluid. So today, shift flare is gone but I have no 4,5,6. It's worse than ever! Maybe the new atf's cleansing agents have cleaned any friction left on the clutch pack to allow me to shift?

I've decided on swapping the tranny with one from a scrap yard. Here's my problem:

donor 1: 2011 MCS auto with 60,000kms
donor 2: 2007 MCS auto with 145,000kms

I would immediately go with the 60,000km transmission except that the 2011 has a part number of GA6F21WA-TANH for the N18 matched auto. The 2007-2010 n14 auto has a slightly different part number: GA6F21WA-TANB. realoem also lists the different part numbers. The Bentley Manual identifies different final drive ratios for the manual transmission but don't list anything different about the 2 auto part numbers.

Can anyone shed any light on the differences between the two transmission part numbers? Has anyone taken an N18 automatic (2011-2013) and put it in an N14 (2007-2010)? last thing I want to do is put the 145,000km transmission in and find out it has the same issue as I have now (or have it pop up soon after replacing it) or purchase the n18 transmission and find out that something doesn't line up.

Thanks in advance.

 

Can't answer your question, but in discussion with a transmission shop they said the problem is most likely the clutch pack is not holding the pressure, resulting in the loss of gears.

I'm currently looking for a transmission, and see tons of MY11+ available but not many in our series. When I start asking the dismantlers detail questions, they all start mumbling. I'm going to stick with trying to find same series tranny as this car is too darn sensitive.

Following along, and keep us posted to your findings. GL. And I'll stick with a tranny with less than 100k miles, as it appears that once the miles creep up , reliability lessens.

 

Clutch Pack: That’s what I’m thinking as well. I was going back and forth between rebuilding and swapping but at the moment, I think I’m going to go the same route as you and go with a swap.

I’m sure someone has tried to mate an 11+ with an n14. I just wish we could hear what their experiences have been. I’ll keep digging and will let you know how I make out. My main worry with the swap is that I’ll have a similar mileage transmission that hasn’t ever had it’s atf replace and I’ll be back where I started in no time. (If not immediately after the swap.)

In the meantime, if anyone can chime in with their experiences with their transmission swaps, please let us both know!

 

Did my 7th drain/refill on the '12S with Royal Purple @ 78k miles (I was really lazy on this one ->). Been doing them every 10k since the car was new. This time I added the Liqui Moly ATF Additive since I don't plan on doing any more drain fills but who knows!

 

To put closure on this, I ended up swapping the tranny with one off of ebay. Think it had 80k miles on it. It's been over a year and running fine, now the rest of the car is a different story. What a fun POS it is, lol. Keeping it running as my son, a new driver, is now using it.

 

I've since put a few thousand miles since the last drain/fill and the Liqui Moly ATF Additive has helped with the 'stock' (lockup?) roughness in the transmission at low speeds/throttle. Not sure if another drain/fill with more additive will add more benefit. Upshifts under power are fine, downshifts (auto or triggered) are also good. I'm at a stage 2 manic tune running map C fulltime so more torque but no track time on stock S turbo. (knocks on wood).

 

Hi, I have a 2005 cooper s, 175K km, at 100K (2012) had the valve body rebuilt and is still shifting very smoothly, however recently noticed drops of red fluid on passenger side, I assume this is transmission fluid as it's pooling along the edge of the oil pan and dripping below the engine mount knuckle. I also found that it's seeping between where the transmission is mounted to the engine and the pan is not leaking. I fear this is a very expensive seal repair and may not be worth keeping the car after 21 years. I've had a lot of work done over the years, most recent items. I have some pictures of the leaks I also researched that if the inspection hole is clean which it is then the leak could be external perhaps passenger side output shaft seal but I haven't taken it in to investigate yet as I'm afraid to drive it and cause damage.





1. Sept 2025 radiator fan (stage 1 failed for the 3rd time in 20 years)
2. March 2025 - bran new P7 run flats
3. 2024 - new rear pads, rotors and rebuilt calipers, pcv valve, oil pressure switch
4. 2022 - new PS pump, front shocks, mounts, control arm bushings

It's in decent shape and I may have to part with it if this transmission issue is too costly.

Cheers

Anthony

 

Hi, Update: Took it to the dealer today and together with the shop manager we looked at it and we could not trace the leak to the transmission, both output shaft seals were dry and clean and even inside the inspection hole in the bell housing was clean. It's a mystery we did trace some of the red fluid pooling at the oil filter housing area which is bizarre. He said to keep an eye on it did not look critical at the moment and will have to revisit maybe when I get an oil change in a month or so.

Thanks

 

Hi, updated I'm convinced it is an ATF leak and now I suspect it is internal as I did a short couple of trips and it accumulated again on the passenger side it must be forcing it's way along the engin oil pan. I got a sample on my finger to smell it and it did not smell like engine oil. But car still shifts and drives ok for now, I will not be driving it until I get to the bottom of it but I am also not spending thousands to take it off the car not at this age and KM, 175K km. I am the original owner, it has new tires and radiator fan, PS pump is only a couple years old too. Perhaps I will try to sell it for anyone who wants some really good parts.

Thanks