Transfer case chain (ATC450)

The most common symptom of a stretched ATC450 chain is a jerking or “skipping” sensation during hard acceleration. You may also hear a clicking or popping noise coming from under the vehicle as the chain teeth jump over the internal gears due to lack of tension.

Yes, the ATC450 transfer case was primarily used in the BMW X5 E70 LCI (facelift) and X6 E71 models produced between 2010 and 2013. If your vehicle has the ATC450 unit, this chain is the correct replacement part.

While jerking can sometimes be related to the transmission or tires, in BMW xDrive models, it is often caused by a worn transfer case chain. When the chain stretches, it loses its ability to transfer torque smoothly to the front axle, leading to hesitant or jerky movement.

Absolutely. Replacing the chain is a cost-effective way to rebuild your ATC450 transfer case. As long as the internal gears (sprockets) and the actuator motor are in good condition, a new chain will restore the 4×4 system’s functionality.

Frequent hard acceleration, mismatched tire sizes between the front and rear axles, and neglected transfer case fluid changes are the primary causes. Using tires with different rolling circumferences puts constant stress on the chain, leading to premature stretching.