ATC45L Transfer Case Adaptions Failure

[Nifty100]

Im New to this forum and hope that someone has experience with ATC45L Transfer Case Adaptions and can help with the issue I am having.

I have a 2017 F16 N57D30A that has 3700Km on the Odometer. We have been unable to Calibrate the Transfer Case VTG using ISTA+ and numerous other tools. The VTG module has been replaced but still fails the calibration routine although it appears to complete the process. The Vehicle has been to BMW Agents who advise that the Transfer Case will have to be replaced. The Fluid has been replaced with BMW DTF1 Fluid and the recommended BMW supplied Additive has been used.

The current Codes are:
440105 Transfer Box VTG Calibration Faulty
48097D Transfer Box: Fault, Clutch Position Known no Four Wheel Drive
D355F8 Signal(xDrive actuator information 19.3.4 invalid, transmitter VTG

The Transfer Case has been opened for inspection to confirm that no mechanical issues are apparent - nothing obvious. I have a new Clutch Pack (Friction Plates, Steel Plates, Springs ) to install in the hope that it will solve the problem. I note that members of this forum have successfully replaced Clutch Packs
Can anyone advise if the timing of the VTG Worm Gear/Clutch Quadrant is important or is it a random mesh that the VTG adaption process will adjust for.
The 4 Digit Transfer Case Class Code on mine is 4202 - What does this mean. Will it change after Clutch Pack replacement.

Does anyone have experience with these VTG Modules/ATC45L Transfer Cases.

Thanks in anticipation.

[Nifty100]

The Fault with mine turned out to be the Oil Seal on the VGT Drive binding up on the Shaft. Close inspection revealed that the Seal was not fully inserted into the Housing and was inclined slightly.
Its easy enough to check /replace it. Remove the Rear Transmission Mount and the VGT. The Slotted Shaft in the Transfer Case should rotate freely until it begins to load up against the clutch Springs. Mine had noticeable resistance and juddering as it was rotated slowly with a Screwdriver. The Seal was not Sliding freely on the Shaft. You can remove the Seal but you will need to Punch a Hole in it to facilitate removal. I replaced the Silicone Seal with a Seal 21x8x6mm off the shelf at the local Seal Supplier. I immediately noted that the Shaft rotated freely. I fitted a new Clutch Pack while I had the Transfer Case on the Bench but I cannot identify any issue with the original Clutch Pack. After refitting I ran the Adaptions Procedure with ISTA+ and it was successful and has been OK ever since.

[Chilled]

if you don't mind me asking, where did you get the clutch pack from? Any specs/dimensions on the clutches/steel plates.

In your searches, did you manage to find strengthened gears, chain and the actuating paws?

[scotty339]

Originally Posted by Chilled

if you don't mind me asking, where did you get the clutch pack from? Any specs/dimensions on the clutches/steel plates.

In your searches, did you manage to find strengthened gears, chain and the actuating paws?

https://cobratransmission.com/BMW-AT...nits-And-Parts

or more specifically...

https://cobratransmission.com/BMW-AT...5L-Clutch-Pack

[Chilled]

Cheers, those look like the stock service kits. Do you know if any upgrade packs kits. Or places that can inc the chain, actuating paws?

This is more a discovery, as I've heard guys saying they've strengthened these things, but never where they got the gear from.

I know RayB has packs for the 8HP, and sonnax has nice valves, but didn't see anything for the TC/Rear Diff.