1

Remove   the gearbox and drive gear.

See   current Maintenance Manual Line (MML) for the respective engine type.

2

Perform   a crankshaft run-out inspection on the PTO side.

See current Maintenance   Manual Heavy (MMH) Chapter72-10-00 for the respective engine type.

3

Perform   a crankshaft distortion inspection.

See current Maintenance   Manual Heavy (MMH) Chapter 72-00-00 for the respective engine type.

4

If any of the above   measurements are exceeded, the engine needs to be shipped to any Rotax   approved overhaul facility for repair/overhaul.

5

If the above measurements are within limits, perform service of the whole gearbox in accordance with   current Maintenance Manual Heavy (MMH) Chapter 72-10-00 for the respective   engine type.

6

Perform NDT inspection of the   propeller shaft (1), gear set (2) and gearbox housing (3). For 912, 912 i and   914 (series), also perform NDT inspection of the dog hub (4) or clutch hub   (5).

NOTE:   In the case of 912 i, 915 i and 916 i   engine series, the gearbox housing has an electrophoretic coating (black)   that does not require removal in order to perform the crack detection.

7

If cracks are detected on any of these   components the parts need to be replaced.

NOTE:   The gearbox mounting screw holes, dowel   holes and roller bearing fixa-   tion screw holes must be carefully inspected for any cracks or abnormal- ities.

8

Disassemble overload clutch and damper clutch. See Chapter 72-10-00 Maintenance   Manual Heavy (MMH).

NOTE:       The overload clutch of the 912, 914 and 912i Series, needs to be shipped   to any Rotax approved overhaul facility for repair/overhaul.

9

Check all given wear limits for the   gearbox assy. See current Maintenance Manual   Heavy (MMH) Chapter 72-10-00 of the respective engine type section “Inspection” and “Wear Limits”.

10

Replace all 100% replacement parts in accordance with current Maintenance Manual Line (MML) chapter 05-50-00, for the respective engine type.

11

If the rest of the parts are not within given limits or have unusual wear or damage, the parts need to be replaced.

12

Assemble gearbox. See current Maintenance   Manual Heavy (MMH) Chapter 72-10-

00   of the respective engine type, section “Assembly”.

13

Re-install drive gear in   accordance with current Maintenance Manual Line (MML) chapter 05-50-00, for   the respective engine type. Check the crankshaft run-out. See current Maintenance Manual Heavy (MMH) Chapter 72-10-00 for the respective engine type.

14

Re-install the gearbox   in accordance with current Maintenance Manual Line (MML) chapter 05-50-00 for   the respective engine type.