The ROTAX 240880 is a factory special tool used as a crankshaft locking screw (thread bolt) for Rotax 912, 914, and 915 series aircraft engines. It is used during maintenance procedures to precisely lock the crankshaft in the correct TDC (Top Dead Center) position before performing tasks such as gearbox work, ignition timing, or major engine assembly operations.

The tool threads into a dedicated crankcase port and engages a machined recess in the crankshaft. Once seated, it physically locks the crankshaft in position, preventing rotation while allowing safe and accurate maintenance alignment.

Rotax explicitly specifies this tool in maintenance manuals and warns against using substitute bolts, as incorrect geometry or material strength can damage the crankcase or crankshaft locking surface.

Key features include:

OEM Rotax special service tool (crankshaft locking pin)
Part number 240880 threaded locking bolt
Used for precise TDC positioning and crankshaft immobilization
Engages machined recess in crankshaft for secure locking
Required for specific Rotax 912 / 914 / 915 maintenance procedures
Prevents crankshaft rotation during gearbox and timing work
Designed for repeated maintenance use (not a consumable part)
Precision thread fit for crankcase locking port
Must be used according to Rotax Maintenance Manual instructions
Improper substitutes can cause crankcase or crankshaft damage
Used by certified Rotax maintenance personnel (iRMT level service)
Part of official Rotax special tools kit