Gearbox Repair — Basic Information (BMW 3 Series E46)

Gearbox repair is too complex to be done in a garage. In addition to the need to remove and install very small parts, it is necessary to accurately measure various gaps and install adjusting shims of different thicknesses. Internal gearbox components are very expensive and difficult to buy. Therefore, if a gearbox malfunction occurs, we recommend that you take it to a service station for repair or purchase a refurbished unit.

However, for an experienced mechanic, gearbox repair is entirely possible if you have special tools and equipment, and if you perform this work with great care.

To repair the gearbox, you will need pliers for removing inner and outer spring rings, bearing pullers, an impact device, a set of punches, micrometers, possibly a hydraulic press. In addition, you will need a large workbench with a vice.

When disassembling the gearbox, carefully mark all removed parts to facilitate subsequent assembly.

Before disassembling the transmission, try to determine the cause of the malfunction. Some transmission malfunctions are associated with certain components. Identify these components (see "Troubleshooting"), and the transmission repair will be much easier.