It is a well-known issue on the BMW N54/55 platforms that your serpentine belt can fail for various reasons, when this happens you have a high chance of the belt getting sucked behind the front damper, and then being pushed past the crank seal into your oil pan. From there it can get sucked into the oil pick up causing total engine failure, even if you do not lose the engine it is a COSTLY repair to remove the sub-frame and drop the oil pan to remove the belt.
The best way to combat this is to watch for oil leaks and keep up on your maintenance. BUT Even with those preventative measures, pre-mature belt failure can occur. This crank seal guard installs over your front crank seal and will keep the belt from being sucked in if a belt failure does occur. This is a cheap way to ensure you do not end up having to replace your motor from oil starvation due to an ingested belt.
Our seal is different from those already on market, it is 100% billet, with no welds on the tabs to break, no cheap bent thin steel pieces. 100% Billet 6061-T6 aluminium, anodized black for long time corrosion resistance.
We highly recommend you install WITH a crank bolt capture (CBC) at the same time, as you have to remove the damper anyway. Then you will get the benefit of helping eliminate the dreaded spun crank hub and the crank seal issue
Please note: In a small number of instances the capture will not line up with the crank bolt, and the damper bolts. In this case, suggest putting a little extra stretch on the bolt to get them lined up, or you must install a new bolt clocking it correctly to fit the capture.