Sealing Sleeve or Mechatronic Unit Replacement Tips

[kaineb]

I couldn't find all the info i needed in one place so i figured i would put a few tips together. I have nothing to do with any company here, BMW, or any other affiliation. Use at your own risk.

Symptoms:
Erratic shifting or bumping in one or more gears in any range, any speed, any throttle.

Preliminary:
(1) Check for leaks at the pan and sealing sleeve (where electrical connector is at back of transmission)
(2) Change fluid and pan with integrated filter and see if it corrects issue.
(3) Have software updated at BMW, etc under SI B 24 03 09 or similar for your specific model.
(4) BMW may recommend 2-1 Tip in. Start car out in 2nd rather than first. I opted not to perform this. Its not a real fix, its a band-aid.
(5) At this point if all has been unsuccessful it is time to look at swapping the Mechatronic unit. A DIY is available

Choosing DIY or not:
This is a very expensive repair at BMW, around $5000+. Slightly cheaper at an Indy. This is a reasonable DIY that with patience i believe anyone that can turn a wrench can do.

Ok im ready to DIY!
I have looked around everywhere and the cheapest place by far i found is The CTSC They are a little slow getting back and there is no phone to contact them, but patience will save you big $$. Choose the correct model for your car or email them for assistance. There is a core charge.

What the heck am i getting?
I wondered this myself and as it turns out it is a genuine ZF factory rebuilt Mechatronic unit. Yeah!! The unit will come programmed for your vehicle. You will just have to supply your VIN. You will have to ship your core directly back to ZF.

What do i do until i get my part?
It will be to you lightning fast so use this time to get your car up in the air and pull the old Mechatronic unit out. Study the PDF from thectsc on installation.

Ok im lazy, just tell me. (messy messy messy job)
- Drain trans fluid, leave bucket under drain.
- Unscrew all pan screws except for 2 located on either side of the pan closest to the front of the pan (opposite side of pan than drain). Slowly unscrew these 2 until the pan is at a good angle downward and leave it there for several hours to drain.
- Remove the bucket and put a huge pan underneath to catch all the mess.

Ok lets get down to business!
- Pull down on white locking tab inside rear of trans housing to release the sealing sleeve.
- Take a big ash screwdriver and gently unlock the external electrical connecter by prying up 1/8 turn and move out of the way.
- Now pry GENTLY on the sealing sleeve away from trans with screwdriver and it should pop out. Route it around the side and by the heat shield. It will go though it is tight.

Time to remove the Mechatronic unit. (don't remove exhaust,etc)
- Follow CTSC PDF instructions on what screws to release, Ebrake, etc.
- Once you get down to the last 2 screws hold it up with one had and release the last 2. It will come straight down out of transmission.
- Place it on pan and leave it for a while. The trans will drain again with the mecho unit.
- Remove the double seal that is in the front of the trans. It is 2 squares and will easily come off.

Wow this is a big box!
- Unpack the box and be careful not to bang the unit or touch the electrical connector pins.
- Clean your old mecho unit and repack it and send it on its way.

I want my car back, i miss her
- Lube the new square seals and put them up in the transmission. They are keyed and can only go in one way. They will stay up there.
- Get 2 screws ready and pull white locking tab down on mecho unit. also remove protective cap on electrical connector.
- Push mecho unit carefully up in place and wiggle slightly until it seats. Take care to align the gear selector in the proper groove as explained in the PDF. Place 2 screws at either end of center of unit and hand tighten.
- Put all screws in hand tight then follow PDF instructions for tightening.

Final lap (always the trickiest)
- Lube o-rings on sealing sleeve and route back up into area with thinner part towards trans and key down. Rotate until it feeds into hole and push with hands.
- Now grab a soft handled dead blow hammer or similar and provide gentle pressure against the sealing sleeve until the white locking tab will slide up without much force. It is locked in place until you provide pressure against it with the sealing sleeve. Do not force it.
- Lube o-ring on tube sticking up from pan filter and guide into hole in front of trans. Install screws as per PDF.

One last thing! Fluid...
- Make sure the car is level first.
- Fill the car as per TIS instructions and monitor the temperature.
- I have had good luck with filling a 5 gallon bucket with 7 liters of fluid and placing under the fill hole. When it spill out it will go right back in the bucket.
- I fill the trans pan, start the car for 10 seconds and repeat until it wont take any more without running constantly.
- Turn off traction control and cycle through all gears several times.
- Now if you are in proper filling temp range finish filling it until it spills out and that is usually it.
- Put your fill plug back in and you are good as golden.

[matthewt]

Have you finished the Mechatronic replacement yet? How's it running??

[White94RX]

Where's the part about having to program and encode the mechatronics? They usually don't work without being programmed/coded.

[kaineb]

Edited and added line about programming.

Matthewt : Car is running smooth as silk now. Hope this helps others.

[E60ordie]

Great write up. Thanks for posting.

[bud92273]

Great write up. Thanks for posting.

+1

[White94RX]

That info is on the suppliers website. But I can put it in there. Comes per-programmed. Just have to give them your vin.

Gotcha. When we order them from BMW, they're obviously not coded, and not even programmed. The car won't really drive until it's done. Just wasn't sure how the average home mechanic would get it programmed. But if it's preprogrammed, and coded to your VIN, then problem solved.

[matthewt]

SWEET!! That was my next question...so give em' $1600 and the vin, some elbow grease and a few hours, and you have a new tranny!!! Score!! Sure beats the hell out of 5k...

[kaineb]

The majority of the countless threads i have read has all of the items listed at the top to check first done by BMW for $$$. Then as it came down to no other option they pleaded with BMW and sometimes it was covered, most of the time tough luck.

In every case but one again that i read, the Mechatronic replacement was the only fix for the behavior described above thus why i gave it a shot. I can fork over a total of $1900 with fluid change complete and justify that on my bimmer. Especially if it solves the problem. I cant justify $5000+ for the same repair at the dealer. And i believe that does not include a fluid change.

[racooper3]

The majority of the countless threads i have read has all of the items listed at the top to check first done by BMW for $$$. Then as it came down to no other option they pleaded with BMW and sometimes it was covered, most of the time tough luck.

In every case but one again that i read, the Mechatronic replacement was the only fix for the behavior described above thus why i gave it a shot. I can fork over a total of $1900 with fluid change complete and justify that on my bimmer. Especially if it solves the problem. I cant justify $5000+ for the same repair at the dealer. And i believe that does not include a fluid change.

kaineb Most excellent write up on the mechatronic issue for the 6 spd tranny. I think since we know that in most cases it is the mechatronics, then I am going to skip all the dealer checklist items and go straight for the $2K option and replace the whole dang thing. I just replaced my tranny pan filter and did a tranny flush to hopefully address it and it did not.

As long as it doesn't get much worse in the shifting and frequent slamming, then I plan on holding off on this until 30k miles. I have it printed out and in my folder under major drivetrain repairs. I haven't read any issues about serious damage to the gearing, etc. I think patience and moving from manual to auto shifting to avoid the issues altogether will be my tactical move. I can always drive fast and avoid that 4th to 5th gear shift hesitation.

Thanks again for the write up.

[kaineb]

Note on Fluid :
If you have decent miles and/or you don't want to spend the money on new fluid you can save it in a clean 5 gallon bucket with lid from walmart. This will save a few hundred bucks.

I even run mine through a clean cotton tshirt to filter anything out before going back in. The reason is is that i do some side work on Bimmers and the dealers dont want to pay for fluid. So i clean it best i can and back in it goes. Never had a problem.

[sevins]

ABSOLUTELY GREAT WRITE UP!

I do have 3 questions however
1) what was/is the malfunction on the car to diagnose it as needing a mechatronic unit?
2) You mentioned a TIS, could you post link for said TIS
3) Could you detail what you did exactly regarding the programming?

Just a side note...the Castrol trans oil mentioned on many other threads seems to work, at $7.99 per quart seems cheap enough to not have to reuse old fluid...just my two cents

[m5ccie]

Why not just replace the solenoids instead of the entire unit? I hear these are the main cause of hard shifting issues.

[eitan37]

Hello
Just replaced the seal between the mechatronic and transmission,all my transmission problem gone...befor that my 2002 745li was running grate until warm,then when shifting between D to R there was a massege that the car is in N possision,I thurn the car off and on again and the transmissin function again,The dealer (in israel) hook it to the computer and told me that the sheeft handel need to be replaced.Thanks god i looked in this forum and found a way to fix this by myself..Thanks,Thanks and Thanks

[shervinj]

Hi Guys,

I just had the 4 sleeves changed, new fluid, new plug, and new pan/filter.

My 2005 530i was shifting rough from 1st to 2nd and 2nd to 1st. Took it in and on the test drive with an indy shop the transmission warning came one and then it got all crazy on us. Car would get stuck at 4000 rpm etc.

He explained that this is the first step to resolving the transmission issue and he didn't want to put in a transmission if it is not needed. Which matches what everyone seems to be saying.

Got the car back and it drives well but there is still a small thud between 1st and 2nd. Mechanic said to drive it a week and see if the new fluid helps. He said this next will indicate wether the tranny will need to be replaced or not.

Who here has had the thud go away completely and who still has one?

[DaHose]

I also have an E24 M6, so am familiar with the E24 auto trannies. E24 owner feedback is that when it shift weird, opening up the valve body and cleaning out the passages, screens and solenoids fixes everything.

Everything I have read convinces me that the solution for a mechatronic tranny. is a $700 parts bill and full rebuild of the mechatronics unit. If you do that the moment you notice anything odd in the transmission, I am confident you would get smooth shifting back with no worries about burned clutches.

Jose