[Wilsonized]

Hey guys,
A week ago my transmission slipped once, then a few days later again, and again recently but this time it did not come back. had to pull over and noticed it would not get into gear so as to protect itself, a drivetrain mailfunction warning appeared on idrive. I tried changing the oil pan and fluid on my transmission after hearing that no/low fluid can cause the transmission to be stuck in park. I drained the oil and found the oil to be have a watery consistency and was pretty dark. was not milky. I found traces of shavings on the mechatronic valve body and after digging further I'm seeing a lot of people say this code 421342 "position specification: undesired power transmission in neutral detected." is basically RIP for the transmission. I also noticed the bottom of the bell housing was completely wet. Additionally I've been having shuddering issues with xdrive. I pulled the VTG fuse after a tire change recently because the transfer case felt like it was going to blow up. Stuck in park after a week of driving it like that. So a few questions..

I have a sample of oil, how can I check for shavings/overall health?
Is it the transmission? How can I diagnose empirically? I have ISTA.
Is my transfer case broken? How do I rule it out?
where is the oil at the bottom of the bell housing from?
What is the average cost of a junk yard transmission swap?
What transmissions (part numbers if possible) are interchangeable with this model?

Any help appreciated, thanks!


X5 F15 3.0L Gas xDrive35i Msport
VIN Last 7:0K42451
Transmission: GA8HP45X
Transmission Part Number: 24008601174

Thank you!