Marathon — Main Rotor Removal
Repair & overhaul
From a Marathon service manual — check it applies to your exact model before use.
Before you start
- Special care must be taken; winding damage could result if rotor hits the main stator.
- Do not apply any force to the generator fan for lifting or rotating the rotor.
Procedure
- Remove the exciter armature and PMG (follow earlier instructions).
- Single bearing: remove four capscrews holding bearing caps to front end bracket; remove outer cap.
- Two-bearing: remove coupling or sheave and key; remove bearing lock and bearing cap capscrews.
- If screen assembly is mounted, remove bolts securing it and remove the screen assembly.
- Single bearing: remove capscrews and hardened washers holding drive discs; remove discs and spacers.
- Single bearing: remove SAE adapter; two-bearing: remove drive end bracket.
- Using rotor lifting fixture and hoist, remove rotor assembly through the drive end.
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Source: Marathon service manual. Steps and values are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.