a cut away from a 1998 bmw 323iS with a windowed ZF310 trans and m20 single mass flywheel. the transmission used to be in an M3 track car, the release bearing failed, overheated and friction welded itself on to the transmission input shaft guide tube. the windows were cut in to the bellhousing in non structural areas and it was installed with a new guide tube on a 1998 323iS to see what would happen. Input shaft bearings were very worn in this ZF, hence the wobblier than average release bearing here.