E53 3.0d 2006 Transfailsafe trifica
 

Hi, new to here. A rather complicated problem, for me anyway. So, in August dsc/4xr light came on, plus Transfailsafe. To note, good battery, Sas changed and calibrated, new alternator, new transfer box actuator. BMW had the car for diagnosis. Changed the electronic connector on the gearbox. 2 days later, same symptoms. They now say, transfer case, but I'm not convinced. Yesterday I removed fuse 46 to deactivate the transfer case. In theory car should drive in 2wd, albeit with warning lights. Car drove normally but the dropped into Transfailsafe. Any ideas would be gratefully received.

I had the same symptoms on clients 328 and sure enough. I have to replace the transfer case to fix it. I found a quality used transfer case including the actuator for about $500 shipped if I remember right it came out of Texas. in his case, he actually broke the front driveshaft and was driving in 2 Wheel Dr. mode for quite a while before he got the eventual transfer case error.

you could try a hardware 2 Wheel Dr. by taking the prop shaft off the front like we had. in his case, the Impact that broke the front prop shaft also damaged the seal on the front of the transfer case so the oil leaked out and that’s what killed it.

Welcome to the board. Can you read BMW specific codes? The transfailsafe code may be causing the transfer case triangle. How old are fluids? The transfer case has clutches. They adjust every time at start up.

Fluids in the gearbox are new. Main dealer changed the electronic connector on the gearbox and replaced the filter, bolts and fluid. Transfer case fluid is unknown.