Robinsons R66 - 63-21 Yoke and Seal Replacement

Page 63.8 Chapter 63 Main Rotor Drive System MAY 2015
63-21 Yoke and Seal Replacement
Refer to R66 Illustrated Parts Catalog (IPC) Figure 63-3.
A. (Tail Rotor Drive) F908-1 Yoke Assembly and Seal Removal
1. Remove tailcone cowling assembly per § 53-23.
2. Refer to Figure 63-1. Remove hardware securing C947-3 (forward) plate assembly
to F908-1 yoke assembly, and C947-3 (intermediate) plate assembly to F196-1 fan
shaft, noting hardware removed. Support weldment to allow clearance for yoke
removal.
3. Cut and discard safety wire securing F904-1 plug to yoke assembly. Engage rotor
brake and remove plug, then remove yoke.
4. Remove hardware securing F254-1 cover with C966-8 seal to F006-1 main rotor
gearbox. Remove cover.
5. Using hydraulic press, press old seal from cover.
B. (Tail Rotor Drive) F908-1 Yoke Assembly and Seal Installation
1. Refer to Figure 63-1. Remove F266-1 spacer and replace A215-027 o-ring, as
required. Reinstall spacer.
2. Clean and dry F254-1 cover; verify open face of seal points toward gearbox and
press in new seal until completely seated.
3. Replace A215-149 o-ring, as required. Install cover assembly over pinion shaft.
4. Verify yoke and pinion splines are clean and undamaged. Coat splines of pinion
with B270-21 protectant and install F908-1 yoke assembly. Lubricate F904-1 plug
threads with A257-9 anti-seize and install plug. Engage rotor brake and special
torque plug per § 20-33. Install 0.020-inch diameter lockwire and safety plug to
yoke assembly. Tuck pigtail behind yoke flange.
5. Install hardware securing C947-3 (forward) plate assembly to F908-1 yoke assembly,
and C947-3 (intermediate) plate assembly to F196-1 fan shaft, as removed. Shim
tail rotor driveline per § 65-30. Standard torque nuts and palnuts per § 20-32, and
torque stripe per Figure 5-1.
6. Install tailcone cowling assembly per § 53-23.
7. Set hall effect sender-to-magnet gap per § 63-40.