This is a genuine BMW roller guide front left, part number 51 32 8 128 729. The number stamped on the part is 51328128729; BMW's catalog files it under the short number 8128729. You will find it on our Interior Body shelf, under Other Body equipment parts. It supersedes the older number 4195577, so a part carrying that number is the same part.
It fits the E36 coupe and convertible (318i, 323i, 325i, 328i and M3, 1992–1999), with the M42, M43, M44, M50, M52 or S50 and other engines — and the European-market versions.
BMW draws it on 3 diagrams, among them Door Window Lifting Mechanism Front (51_0416) and Door Window Lifting Mechanism Front (51_2055). It weighs about 130 g (0.3 lb).
We have not had one on the shelf yet. Request it and we will tell you when one comes off a car.
