 The large gear with a transmission modulus of 10 is mounted directly on the axle, whereas the small gear is on a shaft which is mounted on 2 ball bearings (on early trains) or roller bearings (on later trains).The gearbox casing is mounted on the axle by means of a sealed roller bearing, and is also attached to the truck frame via a special suspension.Initially this suspension comprised a sickle-shaped link with 2 rubber and metal shock absorbers, but beginning in 1969 this was replaced by a vertical rod with 4 such shock absorbers (as on the ER22).