Without wanting to redux too much of the volumes of information you can get on this subject, both here and the BMW sites, I had a go at fixing mine yesterday and thought I'd bore you all with my perspective.

The sleeve leak can be elusive - this is because normally after the car is stopped the fluid level in the tranny is not high enough to reach the sleeve. Over several days oil makes its way down to the sump (guess this is from the TC?), eventually getting up to sleeve height. Once this happens the drips start. Use the car daily and you won't suffer.

So - the fix is straightforward. 7 litres of lifeguard 6 - check, new sump pan/filter - check, sleeve - check. Car on a level surface in off road height.

The filler plug can be difficult to shift if it has been overtightened, but that shouldn't bother the seasoned home mechanic should it? Loosen filler, then drain the existing oil through the plastic drain plug on the sump (this one should be easy to shift).

Disconnect negative battery terminal while the oil drains.

Disconnect the wiring plug from the mechatronic sleeve. This has a stiff locking ring but just about manageable.

Drop the old sump leaving a couple of bolts at the front loose but still engaged. The rest of the oil will happily run back to the drain hole along the drooping sump. Keep it like this while you sort the mechatronic sleeve (the interlock can be reached without fully removing the sump) - this minimises the drips on your garage floor.

The sleeve - hmmm. Old one comes out easily. Lube the new one with fresh oil and place in gently, rotating until the alignment tab engages with the one on the mechatronic. Now press home. Engage interlock**

Replace the electrical connector and engage the locking ring.

Now it's time to drop the old sump and replace it with the new one. Torque the (21) new bolts up to 10nm (in the correct order), and then it's just time to fill the transmission. Pump in oil through the filler until it flows back at you and covers your arm in oil that smells just like cat pee. About 2.5 litres as I recall.

Replace filler plug loosely and prepare your pump with another slug of fresh oil. Replace battery negative lead, then connect your trusty IID tool, turn on the ignition, and setup your phone to display the transmission oil temperature.

Now start the engine and move the transmission to 'R' 'N' 'D' and back to 'P', pausing a few seconds at each stage. Remember to chock the wheels of the car before diving under with the fluid pump again (the engine must run while the filler plug is out).

Pump in fluid until you have the next dose of cat pee on your arm. My pump ran out before this happened. In this case replace the filler plug lightly. You probably want to stop the engine while you decant more oil - and if you do you must do the gearchange sequence again after the restart.

Once your arm is moist with smelly overflowing oil, check the tranny temperature. If between 30c and 50c you are finished, replace the plug and torque to 35Nm. If less than 30c wait for the temperature to rise into the range allowing oil to drain out of the filler plug. If above 50c replace plug, stop engine, and wait a long while for the fluid to cool - then repeat.

I had this changed by the garage, along with fluid as you describe - then when driving home I got trans failsafe etc. The plug had worked loose.

I crawled underneath and re-seated it, but like you, couldn't get it to lock. I took it back to the garage, I think they had to push it in a bit further, and then it locked.

I could really have done with your guide to hand to the mech before they attempted it!! This should be in the WiKi! 

Apparently this can happen. This is a wild guess, but if garages have the same issues as I did putting in a new sleeve, I wonder if they try to get away with one of :

* Not engaging the interlock in the sump - although I don't think the sump will go back on with the locking mechanism disengaged ?!?
* Forcing it?

If the sleeve isn't seated properly the electrical connector will not press far enough onto the mechatronic giving the problems you saw. It's then impossible to fix without dropping the sump again...

Is the mechatronic sleeve leak particular to the zf6 or can/does the zf 5hp24 suffer from the same problem?

(Im about to do a full ATF change on my zf5hp24 so am wondering if i should change the mechatronic sleeve or not?)

The 5HP24 doesn’t have a separate sleeve because the electrical connector plug is part of the internal wiring loom. The connector plug does have two O-rings on it (they’re coloured white in the photos) to seal the inside from the outside but they generally aren't problematic like the earlier (orange) 6HP26 seals. You don’t therefore need to worry about this.

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Phil...as ever...thank you for the informative detailed reply.

cheers!

I,m having gearbox issues It had a flush and oil service about 8 weeks ago and I have been getting the odd transmission fault appear on dash in particular when on motorway when accelerating to overtake then this happened.
i'm new on the site and not sure if its ok to jump onto your post I hope you don't mind or can advise the correct way of going about it.
Thanks Graeme


Member Since: 15 Aug 2020
Location: Dunfermline
Posts: 6


Transmission fault

My RR has a fault that one minute it was fine next it had developed this, it starts fine then dashboard has HDC fault, Handbrake fault, suspension lowered, only selected gears available. It will drive but only in 3rd gear or reverse even command shift will stay in 3rd that's in hi/low ratio. I'm away from home just now so had local garage plug it in and they are saying there is no communication between any of the modules. they tried to clear but it won't let it as there is a engine system fault showing that has become a permanent fault which ive had for some time and cant get resolved after lots of money throwing parts at it I believe it is a boost fault but replaced all the common things and turbos. Please help if you can thanks in advance.
Graeme

What codes are stored in the engine system?