Transfer box or transmission not engaging

[jfalcon]

Was at a stoplight on a hill. Once the light changed, made my turn then heard a clatter then suddenly no power was being sent to the wheels. Pulled off the side of the road (still on a hill). Shutdown, restarted then tried to engage in any gear. Had the obdIi cable plugged in so went into protools and looked for errors which there weren't any. Reset the ECU of the transmission, no difference, reset the ECU of the x drive and it would engage for a second then disengage then engage again then disengage then engage them disengage.

Any idea what it could be?

[jfalcon]

When it engages, it actually sends power to the wheels but doesn't keep power there. It also has a thump when it engages now. Something loose or a bracket get busted?

[jfalcon]

Update:
So after the car sat - battery drained because of some cold weather causing the car to go brain dead then revived by the trickle charger, restarted it, cleared the error codes, recoded the transmission, xdrive, and gearshifter along with the parking break to factory and reset all the adaptations, the car does move forward and backwards normally again...

*but*

Still a grinding noise when going from reverse to park or from drive to park.
Does not do it going from drive to neutral or reverse to neutral or neutral to park.

Reading around, it seems like a common issue - but without a causative solution.

Obviously it appears there is something spinning from drive to park that is causing the parking pawl to grind (possibly may even be broken as the car will still move when in park).

Anyone have any experiences relating to this and what was your solution?

[jfalcon]

On another note, the noise it makes when shifting into park is the same as the one featured in the video within this post:
https://xoutpost.com/bmw-sav-forums/...ans-toast.html

[ard]

I look around for service/tech manuals on your transmission (6HP?) and 'parking pawl'.

[jfalcon]

I did find a copy of the 6HP manual and I'm not convinced it is the transmission itself.

I have been able to reproduce the symptoms in this video:
https://www.youtube.com/watch?v=PBoAdbyN23U

Especially in terms of turning the wheel and there being no movement and having movement forward and back if the wheel is straight.

Actually, you can have movement forward and back up to 90 degrees left or right on the steering wheel - but that would be maybe 15 degrees of deflection on the wheels, not enough to turn a corner certainly. What happens over 90 degrees is that no power reaches the wheels.

So this tells me a few things:
- Possibly there is no power going to the rear wheels
- If there is power going to the front wheels, it gets cut off once the steering wheel turns past 90 degrees left or right from center.
- It makes no noise going into gear - nor does it make any noise going into neutral or noise from neutral to park. only when going from R/D to P.
- And another reason why I don't think it's the transmission itself - it engages and does send power properly both forward and backwards (R/D). Which means there is power going from the transmission to the transfer case at least just to deliver it to the differentials either front or rear.