Hello.
My inquiry is directed to the author of this topic; did you manage to solve the problem?
I'm digging this topic up because I have a similar problem. Some time ago in my BMW X3 E83 2.0 d 150 km. 2006 year of production manual transmission, the famous x drive lights came on; 4x4, brake, ABS. When making sharper turns, it jerked terribly, as if from the rear of the car. I replaced the rear wheel speed sensors - it helped for some time because the lights went out. After some time, they came on again and I removed the rear wheel speed sensors to check what was wrong with them. It turned out that the tips of these sensors were slightly worn at the ends, which suggested that the crowns on the driveshafts were swollen and should be replaced. I will also mention that for a long time the car was jerking when accelerating in higher gears, as a symptom of a damaged x drive reducer. I had the crowns on the driveshafts replaced by a mechanic, there were still a few things to do; brake pads, starter. It turned out that the alternator was also damaged. The mechanic did not replace the crowns, but replaced the entire axle shafts with crowns because the old axle shafts were corroded and installing new crowns resulted in them having too much play. He also installed new wheel speed sensors. He kept the car for almost a year, I wasn't in a hurry because I had something to drive. It was time to take the car from the mechanic because I already knew that there was no point in repairing it. He claimed that it was impossible to calibrate the VTG box. I will add that the reducer adjuster and the plastic gear were functional.
I removed the reducer, disassembled it, washed it, and after visual inspection it turned out that several elements needed to be replaced or regenerated. Loose chain, worn needle bearings, large ball bearings that are noisy, worn mating surfaces, strange-looking spacers between the discs in the clutch basket, etc.
I took the reducer to a company that regenerates reducers located in Częstochowa. The gentleman on site, after inspecting the reducer, confirmed my suspicions about the worn elements inside. I didn't wait for mine to be regenerated, I just paid and took the already regenerated reducer of the same type, i.e. ATC400.
Together with the reducer, I bought original BMW oil to fill it with. I poured 0.8 liters of oil into the reducer and installed it in the car. I put everything back together and surprisingly it turned out that only one light on the dashboard was on, i.e. 4x4, orange. I installed the appropriate software on the laptop; INPA along with all the bells and whistles that need to be installed with it and, of course, ISTA. I already had the cable. After connecting the car to the interface, it turned out that INPA does not work properly, but ISTA seems to be ok. It connects beautifully, downloads data from the car, enters modules, etc. I performed the ISTA oil change of the transfer case, calibration, everything seemed to be successful, but the 4x4 warning light did not go out. I also calibrated the steering angle, it was successful. The error that appears in the program regarding this angle calibration returns after deleting.
I connected an old laptop with some old INPA to the interface, but it's kind of flimsy. The error was read successfully; 55C4.
Any suggestions are welcome.
