Drive Pinion Gear

Using bearing race installer, install front and rear bearing races in housing. See Fig 1 . Press rear bearing onto drive pinion. Note any deviations ("+" or "-") stamped on drive pinion. This amount must be added (if "+") or subtracted (if "-") from measurement "C". See Fig 2 .
Heat ring gear to 176-212°F (80-100°C), if necessary. If original ring and pinion gear set is being installed, install drive pinion gear using original shim and new collapsible spacer. If new ring and pinion gear set is being installed, install new shim that is same thickness as original shim.

Fig 1: Installing Bearing Outer Races
Courtesy of BMW OF NORTH AMERICA, INC.

Fig 2: Pinion Shim Measuring Points
Courtesy of BMW OF NORTH AMERICA, INC.