I am trying to decide what might be my best option here.
I bought the car around 18 months ago, and while doing the transmission filter/fluid change I found that a previous owner had tried to cure a leak from around the sleeve by covering it all in an epoxy type substance.
I could not get the harness connector to disconnect from the sleeve.
It still leaks, and so every 6 months or so, I remove the fill plug and top of the fluid level using the proper procedure. Then it drips slowly, especially when parked on the sloping drive.

My concerns are that the harness is bonded to the sleeve and will be impossible to separate. Or worse, the harness is bonded to the mechatronic part.
If I can rotate the mess of epoxy, maybe the harness will disconnect, but do I risk damaging the pins inside when struggling to rotate the harness?
If I drain the fluid, remove the filter, and pull the white tab down, is it possible to remove the harness and sleeve as one unit, which might allow more access to the epoxy to try to remove some?
If I got the harness and sleeve out, could I replace the outer seals on the sleeve and hopefully cure the leak?
Should I just sell the car?
Thoughts?

 

Yikes. Hopefully the previous owner did not epoxy inside the connection.

Don't try and rotate the harness, the socket and plug are keyed. There is an outer ring on the harness connector, normally during installation you rotate it 1/4 turn which pulls the pins into the socket and locks the connector in place. See here: https://www.fcpeuro.com/products/bmw...ng-12527503442



This might be an option. Usually you need to pry to get the old seal out when replacing, and with any luck the epoxy did not stick well to a dirty transmission case. If you could rotate that tab CCW and then pull the harness out, that would be the best first step. Then you could try and get the old sleeve out.

If you get it out, don't bother trying to replace the seals on the sleeve, just replace the whole sleeve. They are a service item https://www.thectsc.com/products/6-s...eeve-3-10.html

Another thought, epoxy is usually pretty brittle. I wonder if some gentle taps with a cold chisel might shatter it? Biggest problem is going to be working with the trans in place, there's little room to even remove and replace the sleeve when it hasn't been gobbed with epoxy. Maybe in this case, you could try removing the driveshaft, trans mount, etc, then drop the rear of the trans to gain room to repair?

 

Thanks for the reply.
I will say that I did swap the sleeve on one of the cars I owned before, the XJR, but many years ago, so I know kind of how it comes apart/goes back together.
If I can get the harness connector to rotate, then hopefully it will also pull out, as the bond between harness and sleeve will hopefully be broken. My concern would be that rotating the harness connector to get it disconnected from the sleeve might start turning the sleeve if both are still stuck together. Then the rotating sleeve has a tab and that might do damage - or is that negated because the wiring harness plug is in there. But if the plug rotates along with the outer locking ring, then it might damage the mechatronic side? Presumably, normally, the plug on the end of the wiring harness is keyed to the tab in the sleeve so that the electrical pins match up, so too much turning force on the lock ring holding the harness to the sleeve might rotate everything and break it off the mechatronic unit?

If the harness/lock ring are bonded to the sleeve, is it even possible to remove both together, after pulling down the white tab, or is there something else that would stop it? If both came out, maybe I can use a dremel or similar to help separate them, and if that failed, that was when I might consider swapping seals over from the new spare to the still glued to harness original, at least gaining an improvement on the outer seals being replaced?

Maybe I just plan on topping it off every 6 months, hoping the leak causes no electrical problems and at least not breaking the transmission while trying to get this out.
I would love to meet the "mechanic" that thought this was a good idea!

 

You could try exploring using a suitable solvent to weaken or dissolve the epoxy (e.g. the excerpt below).
You would just need to be careful that any solvent you use will not have a detrimental effect on the plastics of the plug, sleeve and wiring insulation.
I would normally suggest Acetone, but that certainly could prove to be too aggressive on many typical plastics, so I would start with lesser options first and spot test before applying a full treatment.
You are only trying to weaken it enough to allow the tab to rotate and hopefully release the plug.
Once you have it separated, you can prepare each area separately which might involve different solvents according to the parent material, picks and scrapers.

Heating typical epoxy glues will generally make it become somewhat pliable and freezing it will often make it become conveniently brittle.
The downside of these options is whether the parent material of the connector and sleeve will adequately tolerate these extremes when you apply some force to begin removing the epoxy.

How to Remove Epoxy from Plastics or Glass

"Epoxy might provide a quick fix for repairing broken plastic pieces or sealing a cracked window pane, but it can be a pain to remove on such delicate surfaces. Simply soak a paper towel in isopropyl alcohol (rubbing alcohol) and rub it on the surface until the epoxy loosens. If the epoxy is still stubborn, a stronger solvent such as denatured alcohol (a solvent commonly used to fuel camping stoves) or paint thinner can also be applied to the area with a cloth to weaken the bond, and a scraper tool can be used to gently pry the epoxy from the surface. Once the epoxy is removed, use a clean, wet rag to remove any remaining solvents from the surface."

 

Well that took me down a rabbit hole.
Half the problem will be not knowing exactly what they put on.

But good thinking, I will try teasing some off somehow - JB Weld seems to not be bothered by solvents, but other brands might be.
A soldering iron might be an option, or chiseling it off, or slicing a bit, or sandpaper, or .....
Hot air guns and blow torches do not seem a good match in this case, with a wiring loom there, but maybe in other cases.

Hopefully the 'glue' is more on the outside, holding the locking ring to the trans case, and not bonding the locking ring to the harness connector or to the sleeve.

Sounds like a long day on my back this weekend, hoping I have some reasonable access, I might have to explore the dropping of the rear of the trans, but I read that only got you about an inch more access (I do not have dainty hands!).

I will take some photos too if I can.

 

Correct--the plug itself should stay put while the locking ring rotates. The pins are 1/2 way in when the threads on the sleeve engage, then turning the collar seats them fully. The pins and key on the plug keep it from rotating with the collar. If the plug does rotate with the collar, then yes, the internal female connector has broken.

I'm not sure if this is possible--it might be? The sleeve does pull straight out once you release the inner lock tab (typically with some prying on the sleeve). If you could do this that would give you room to work on removing the glue, or replacing the entire harness connector.

I'm sorry to say, the leaking seal has caused electrical problems on some other people's cars. If it was my car, I'd start by trying to pick away at the epoxy and see where that got me. Try some assortments of picks, screwdrivers, etc. For sure post a picture and maybe we can ID what epoxy it might be. In my experience the usual epoxies (JB Weld, etc) never bond that great and have really poor tensile strength. Twisting or flexing usually breaks the bond.

 

Update, I attacked it with sharp pointy sticks of all sorts today and finally freed it off and got the locking ring to rotate.
I added 3/4 quart of fluid back in as well.
Knowing I can get the sleeve out now, most likely, I will order another filter and fluid kit and use the sleeve I did not get installed last year.

I also found a leak on the lower trans cooling line, at the lower crimp. I unwound a worm drive clamp, slipped it over the pipe, moved it to just above the crimp and tightened it down, that seemed to sort it for now, but I will order new lines asap. I know worm drives are not favoured, but this is just a patch for now.

The bad news was that the bleed valve on the expansion tank fell apart, the head came off, and so the coolant system will not seal. I ordered a new expansion tank from Jeff's company, with next day delivery, so should be sorted by tomorrow night.
I am so glad to get the transmission leaks sorted/lock ring moving, that the pesky bleed valve is but a minor sacrifice.

 

Just a comment on your leaking cooling lines?
These are expensive and a real bitch to fit to your car.

Consider what I did?
The metal crimp holding the rubber hose to the metal line is the failure point here.
Please see this long thread with a couple of suggestions. I replaced the leaking rubber hose section after I used my Dremel tool to cut the crimped connections off the factory lines.
Repair Leaking Transmission Cooling Lines
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So far, the repair is holding.
I swapped the hoses out a few years ago on the XJR, so I sure know about the expense and the difficulty. Hoping this repair lasts long enough that I forget it needs done and just leave it as is.

New expansion tank arrived tonight, took 15 mins to swap it over, test drive went well, coolant and transmission fluid staying where they should be.
The old tank looked original, quite yellowed with age, so hopefully avoided a nipple failure there, one less problem to worry about.

 

Update on the transmission connector sleeve.
Managed to get the old sleeve out, removed all sealant and fitted a new sleeve, sump/filter and 6 qts of Lifeguard 6.
Only 5.5 Qt came out so it was down a little on volume, but no complaints from the electronics, and no metal visible in the fluid or on the magnets.

It's only been a few days, but no signs of leaks now, so fingers crossed.

Coolant has been fine since new reservoir and recrimped hoses. Car is doing around 15,000 miles per year.

 

How did you check the fluid level?
You can't go by volumes? It must be filled at the proper temperature and the fluid will start to dribble out of the fill port.
Did you do this?
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Yeah, thanks for the reminder.

I did it via temperature, 40C, via IR gun.
Car was level, new sump installed, about 3 qts pumped in, engine on, run through gears, added more fluid with engine on, while around 30C, until dribbling out, then left car idling until temperature was 40C.

Did not even burn my hand or knock over a bottle of Lifeguard :-)