Sliding Block Kit (PL72 T, PL72 ATC, ATC450, DCS)

Common symptoms of worn sliding blocks include a noticeable jerking sensation during acceleration, unusual clicking or slapping noises from under the vehicle (indicating chain slack), and hesitant gear engagement. These blocks are essential for keeping the chain tensioned and stable.

Yes, this kit is specifically designed for the ATC450 transfer cases found in many BMW models, as well as the PL72 T and PL72 ATC units used in Porsche and VW Touareg vehicles. It also fits Mercedes-Benz DCS systems. Always verify your transfer case model before purchasing.

These components are manufactured from a specialized high-performance, heat-resistant plastic to reduce friction and noise. Metal-on-metal contact would cause rapid wear on the transfer case chain, whereas this material provides a smooth surface for the chain to glide against while enduring high internal temperatures.

Installation requires opening the transfer case housing, which is a complex task. If you are a skilled DIYer with the proper tools and a service manual, it is possible. However, most owners prefer having a professional transmission specialist perform the replacement to ensure the chain is correctly aligned.

While the sliding blocks stabilize the movement of the chain and take up minor slack, they cannot fix a severely stretched chain. If your chain is excessively loose, we recommend replacing both the chain and the sliding block kit simultaneously for a complete repair.