Service Instruction SI-2026-002R00 New Dog Hub for 912 914 and 912i Gearbox

ROTAX Introduces New Dog Hub for 912, 914 and 912i Series Gearboxes

ROTAX has released Service Instruction SI-2026-002R00, announcing the introduction of new-generation dog hubs for the ROTAX 912, 914 and 912i series aircraft engines. While the instruction does not mandate any immediate action, it provides important technical information for operators, maintenance organisations, and overhaul facilities planning future maintenance or repairs. 

Below is a practical breakdown of what this Service Instruction covers, why it matters, and what owners and maintainers should be aware of.

What Is Changing?

As part of its ongoing development and component standardisation programme, BRP‑Rotax has introduced new dog hub designs for the propeller gearbox assembly. These updated dog hubs feature improvements in both geometry and material properties, delivering enhanced durability and improved long‑term performance of the claw connection within the gearbox.

The change applies to the following engine families:

• ROTAX 912 (Series)
• ROTAX 914 (Series)
• ROTAX 912 i (Series)

New Dog Hub Part Numbers

The Service Instruction introduces three new dog hub variants, which replace previous part numbers on a one‑for‑one interchangeable basis:

All parts are interchangeable, and there is no change to engine weight, inertia, electrical load, or software configuration. 

Is Compliance Mandatory?

No.
ROTAX has classified this Service Instruction as “For Information Only”.

• No mandatory retrofit is required
• Engines already fitted with older dog hubs may remain in service
• The new parts should be considered during maintenance events, repairs, overhauls, or retrofits

This makes the change especially relevant for:

• Heavy maintenance and gearbox overhauls
• Repair of worn or damaged claw connection components
• Scheduled component replacements during MRO cycles 

Important Maintenance Note

ROTAX highlights a critical condition regarding gearbox repairs:

“If claw components are damaged or worn, the complete claw system must be replaced as a set. Partial replacement is not permitted.”

This means that to restore full functionality and performance:

• Both the dog hub and the big gear must be replaced together
• Mixing old and new claw components is not allowed

Installation & Tooling Considerations

All work must be carried out in accordance with the Instructions for Continued Airworthiness (ICA) for the specific engine type

Reference must be made to:

• Illustrated Parts Catalog (IPC) – Chapter 72‑10‑00
• Installation Manual (IM)
• Maintenance Manual Line (MML)
• Maintenance Manual Heavy (MMH) 

ROTAX specifies LOCTITE Anti‑Seize AR (Part No. 297438) for dog hub installation. 

Who May Perform the Work?

Any installation or maintenance action referencing this Service Instruction must be performed and certified by properly authorised personnel, including:

• ROTAX‑authorised distributors or service centres
• Approved airworthiness representatives
• Personnel with engine type‑specific training
• iRMT or Level Heavy Maintenance qualified technicians

What This Means for Operators

For most operators, this Service Instruction is primarily informational — but for maintenance planners and AMOs, it provides clarity on:

• Which dog hub parts are now standard moving forward
• How gearbox repair decisions must be handled
• What components to order during future maintenance events

As engines cycle through overhauls, these updated dog hubs will become the new baseline configuration across the 912, 914 and 912i fleets.

Need Advice or Parts?

For guidance on how Service Instruction SI‑2026‑002R00 may affect your engine, maintenance planning, or upcoming gearbox work, Comet Aviation Supplies can assist with both technical advice and parts support. We can help you identify the correct dog hub configuration for your engine and advise on best practices during maintenance or overhaul events.

To enquire about availability, pricing, or technical considerations, contact Comet Aviation Supplies directly or speak to our experienced team for ROTAX‑focused support.