TCC SOLENOID

[ianst0028]

I've mentioned here in other threads that I've had an intermittent fault coming up on the x5 (i say intermittent but its been happening more and more)
P0740 TCC solenoid and its been only happening on long motorway runs where i'm travelling at a pretty constant speed
The rest of the time the gearbox has been impeccable with nothing to worry me (apart from the fact its a gm box and the fact they seem to self destruct)
I did some digging and (fearing the worst) started looking for a new box .... thankfully i have a kinda tame gearbox specialist who i know through work and after discussing it with him and extensive research online (its like googling your symptoms when your ill go too long and you'll convince yourself your actually dead) i decided to have a punt at changing the oil / filter and replacing the solenoid
I had to wait a week or so for the solenoid to come into BMW from Germany (on a stock order so i got better discount) then i had to find a ramp
so Saturday i had the x5 up in the air and dropped the oil
the oil was old but pretty clean and didn't smell burnt and there were no large lumps in the bottom of the pan
then came the difficult bit .... changing the solenoid .... actually it wasn't that hard but it was nerve wracking because you have to lower the valve body without actually dropping it and i was very very aware that it could all go wrong
once the valve body was lowered enough to get the solenoid out it came out very easily i tested the wiring and the solenoid and although they both tested OK i noticed that the gauze filter on the solenoid was filthy
seeing as the new one was a non-returnable part i fitted it bolted everything back up and replaced the filter / new fresh oil

the only other drama i had was that my atf dispenser decided that instead of filling the gearbox it would rather spray new fluid all over the floor

once i'd finished losing my temper over that (it's on its way back to the manufacturer as i type) I hunted through my tool box and found a 200ml syringe that i've used previously to bleed the brakes on my mountain bike cleaned it thoroughly and used that ..... it took AGES to put 6l of gearbox fluid in @ 200ml a time 

I then ran the car to temperature checked for leaks and checked the levels again ..... then the first tentative drive
took the car up the road through all the gears and back onto the ramp where I let it cool down while I changed the engine oil and filters then I checked all the levels again
Finally I drove home (about 30 miles more than long enough for this fault to show up) with my heart in my mouth waiting for my gearbox to implode

I have to say i thought before changing the gearbox fluid that the changes were already smooth but now they seem to be even smoother

I wish I had thought about taking some pics while I was doing it but I didn't until I sat down to write this post

I'll also give credit to the following post that i followed for instructions to change the solenoid

https://xoutpost.com/bmw-sav-forums/x5- ... ssion.html