AWD E36 Project xti: BMW xDrive vs. Subaru DCCD|Tearing into ATC300 Transfer Case Actuator Pt 1

[@RussellStovetop386]

Excellent video Adam!

[@AdamPE21]

Thank you Shawn! Good to hear from you!

[@kanalnamn]

Well produced, interesting topic. Thanks. (Top tip: Don't film yourself from below if you can avoid it. That goes for all of us.)

[@AdamPE21]

Thank you sir! The advice is noted :)

[@TheChumzo]

Glad I found your channel! I'm starting a similar type of project for ATC35L. (I'll be using it on a car for rally) The one on my car is starting to fail and I have a spare one. One thing I'm curious about is how hot the clutches/oil gets when it's actuating. I'm planning on adding a cooling loop for it.

[@AdamPE21]

There is a temp sensor in the actuator on the ATC300, but I’m assuming it’s more for the DC motor than the fluid temp. My guess is they do some thermal modeling to use that as a part of the control algorithm/limits. Part of what I need to figure out is a balance of responsiveness vs longevity as well…BMW is designing this for 100k miles of daily use, while the application of offroading/rallying (something I want to do with this car as well!) might change up the goals for how its controlled on this project.

[@TheChumzo]

@@AdamPE21 I used to work for an OEM doing CFD for transmissions/drive lines. They will size the clutches for a predicted heatload, but from my experience the duty cycles they use are for basic driving, so the clutches are probably locked/open most of the time. If you're constantly playing around with the torque split it's going to slip a lot more and heat up/wear down those clutches faster. From what I understand Xdelete does this for the e90 sport/snow modes, and they warn against using it for prolonged periods. I'm just curious to see where the oil temp gets to during normal driving compared to a frequently actuating transfer case. And really it's clutch temperature you have to worry about, I could go on forever about oil distribution...but one issue I always dealt with is you don't get enough oil dumping on the clutches and they overheat.