The BMW xDrive is activated automatically when the car needs four-wheel drive. The ATC transfer case, otherwise known as the VTG, is responsible for the switch. It is equipped with an electonically controlled multi-plate clutch, through which 60% of the drive force goes to the rear axle, while the rest drives the front axle. The combination with DSC (in BMW it is the equivalent of ESP) prevents skidding. The response time of this system is less than 100 milliseconds.
The history of xDrive dates back to 1985 and the BMW E30, but in fact the name xDrive has existed since the late 1990s. Gearboxes with ATC transfer cases have been used since then in BMW X series cars, namely X1, X3, X4, X5 , X6, X7, as well as others, such as 3, 5 or 7 series. These cars were equipped with ATC transfer cases of various types: from ATC 300 and ATC 350 transfer case through ATC 400, ATC 450 to ATC 500 and ATC 700. We also distinguish ATC 35L and 45L transfer cases. In the latest BMW (G) series, the transfer cases have been standardised and all feature ATC13.
The clutch is most often responsible for damage to the transfer case and improper xDrive operation. Its wear layer wears out over time, which makes you feel unpleasant jerking mainly when cornering. Changing the road surface (wet – dry, asphalt – gravel, snow – ice, etc) also affects our xDrive, which tries to adapt to the road conditions. In addition, other units are subject to wear – incl. clutch elements, pistones, actuator rings, springs, discs, chains, gears, sprockets, shafts, flanges, oil pumps.
The ATC transfer case is a mechanical part exposed to high overloads and the mechanical elements used in the transfer case wear out after some time, what causes unpleasant jerking.
Jerking is the most common symptom of damage to the ATC transfer case, but not the only one; other signs include a loud roar in the rear of the car, rattling, problems with gear shifting, malfunction indicator lamps flashing on the dashboard.
The transfer cases are also affected by tyre size and condition. With unequally inflated wheels or incorrectly selected car tyres, the drive works irregularly because one side has to travel a greater distance than the other. You can say: such a difference is not a difference, and yet it matters!
What is more, the tyres precisely dedicated to the car should be used. The BMW tyre is different (size) than the Volkswagen tyre despite the same diameter.
Driving with damaged drive is dangerous for you and other road users.
Find the tips on how to check if the ATC transfer case has been damaged below:
Remember, the steps described below are performed on your own responsibility. If it is possible, we suggest you contract these tasks out to specialists – we have the appropriate experience, knowledge and equipment to safely diagnose a fault in your BMW xDrive.
The repair of the ATC transfer case in our workshop always starts with a professional diagnosis. Only after our specialists confirm that the source of the symptoms is the transfer case, we proceed with the repair. Each remanufacturing in our workshop is complete and consists in disassembling the transfer case, replacing all elements in the transfer case that are subject to wear and replacing them with new, OEM parts, assembly, filling the transfer case up with OEM, fresh oil, calibration. On the whole, we leave only the housing, and replace “the inside” with new one.
Thanks to our experience and only comprehensive remanufacturing, we provide a 12 to 18-month warranty with no kilometre limit for the repaired BMW xDrive transfer cases. We carry out repairs on site, at a prearranged time. The total repair time takes approximately 5 hours. During this time, we offer a courtesy car (upon prior reservation). We also offer a lounge room with a comfortable sofa, a TV set with Netflix and WiFi access. We will also be happy to prepare some coffee for you. Our workshop is located in Częstochowa at 240 Św. Rocha Street (ul. Św. Rocha 240), in Grabówka district.
We also repair transfer cases “remotely” – with no need to come to our workshop. All you need to do is send us your ATC transfer case (make sure to pour the oil out of it beforehand!) or commission us to pick it up in the Door to Door system. Then we will send a courier who will collect the damaged transfer case and at the same time deliver the repaired one. Especially for you, we can send a functional transfer case as the first ones (in this case we charge a refundable deposit). You install the functional transfer case at your place, and then send us the damaged ATC transfer case, and we return the deposit to the account indicated by you in the deposit return form.
BMW xDrive cars equipped with ATC transfer case:
BMW passenger cars equipped with ATC transfer case: