16573339_ed2
3
If the Front Rotor Bearing needs to be replaced, press it from the
Front End Plate.
Lift off the Cylinder (27).
Remove the Vanes (29).
NOTICE
Loctite® * No. 277 was applied to the threads of the Rotor
during assembly to prevent the Controller Assembly (24) from
loosening during operation. Before attempting to unscrew the
assembly from the Rotor, apply moderate heat from a propane
torch to the middle of the rotor body to soften the Loctite. Do
not overheat the Rotor. Heat it only long enough to allow the
Controller Assembly to be unscrewed without using excessive
force.
CAUTION
Use only the special Controller Wrench for removing the
Controller Assembly. Do not attempt to disassemble the
Controller. It is available only as a unit and is guaranteed for the
life of the Grinder if it is not abused.
11. Using the No. 77H-950 Controller Wrench, unscrew and remove
the Controller Assembly (24).
NOTICE
The Rear End Plate, Spacer and Bearing are a matched set. Do not
mix the components with those of another set. The Rear Rotor
Bearing is always damaged during the removal process, and a
complete new Rear End Plate Assembly must be installed.
12. If the Rear End Plate Assembly (25) consisting of the Rear End
Plate, Spacer and Bearing needs to be replaced, press it from the
Controller.
8.
9.
10.
13. Remove the Rear End Plate Gasket (26).
14. Using No. 77H-154 Valve Seat Support Retainer Pliers, remove the
Throttle Valve Seat Support Retainer (15).
15. Grasp the Throttle Handle (1) horizontally in a vise. Using a
brass rod 8” (204 mm) long inserted into the air inlet end of the
handle, lightly tap the brass rod with a soft hammer to release the
Throttle Valve Seat Support Assembly (8).
16. Remove the Valve Seat Screw (9), Valve Seat Lock Washer (10),
Valve Seat Washer (11), Valve Seat (12) and Valve Support
Seals (13).
17. Check the Oiler Feeder Plug (14). Replace if necessary.
18. Place the Arbor Housing (22), arbor end up on a workbench.
Lightly tap the end of the Arbor Housing with a soft hammer to
release the Motor Spacer (33).
19.
For Wire Brush Machines,
lightly tap the protruding end of the
arbor with a soft hammer to release the Wire Brush Arbor (39).
20. Remove the Internal Gear (72).
21. Remove the Gear Frame Bearing (70). This is a light press fit.
22. Check the Planet Gears (67) and the Planet Gear Bearings (68) for
wear. If they need to be replaced, proceed as follows:
Using a pin punch and soft hammer, remove the Planet Gear
Shaft (71).
Remove the Planet Gear Assembly (67).
Remove the Planet Gear Bearing (68) from inside the Planet
Gear.
Remove the Rotor Pinion (69).
Remove the second Planet Gear as in steps (a) through (c).
NOTICE
Always replace both Planet Gears and the Rotor Pinion even if
only one Gear shows wear. Carefully check the Internal Gear and
replace if necessary.
a.
b.
c.
d.
e.
Assembly
General Instructions
Always press on the
inner
ring of a ball-type bearing when
installing the bearing on a shaft.
Always press on the
outer
ring of a ball-type bearing when
pressing the bearing in a bearing recess.
Whenever grasping a tool or part in a vise, always use leather-
covered or copper-covered vise jaws to protect the surface of
the part and help prevent distortion. This is particularly true of
threaded members and housings.
Always clean every part, and wipe every part with a thin film of oil
before installation.
Apply a film of O-ring lubricant to all O-rings before final
assembly.
Assembly of the Motor and Throttle
Assemble the Throttle Valve Seat Support Parts. Tighten the Valve
Seat Screw (9) to 12 in-lb (1.4 Nm) torque. Apply O-ring Lubricant
to the new Valve Support Seals (13) before installing them on the
Throttle Valve Seat Support.
Insert the Assembly in the large diameter of the handle, Valve
Seat Screw end first.
Using No. 77H-154 Valve Seat Support Retainer Pliers, install the
Throttle Valve Seat Support Retainer (15).
Press the Front Rotor Bearing (31) and the Front End Plate (30)
onto the rotor shaft.
Grasp the Rotor (28) in a vise, splined end down.
Place the Cylinder (27) over the Rotor, aligning the dowel hole in
the Cylinder with the dowel hole in the Front End Plate.
Apply a film of light oil to each new Vane (29) and insert a Vane,
straight edge out, into each vane slot in the Rotor. If new Vanes
are required, replace the entire set.
* Registered trademark of ND Industries.
1.
2.
3.
4.
5.
1.
2.
3.
4.
5.
6.
7.
8. Check the large inside diameter of the Rear End Plate
Assembly (25) for wear. If the large inside diameter of the Rear
End Plate is worn to 1.516” (38.5 mm) or larger, install a new Rear
End Plate Assembly.
NOTICE
If the Controller Assembly must be replaced, it is furnished with
a new Rear End Plate Assembly. Use only the End Plate Assembly
furnished with the Controller Assembly. If the Controller is
good but the Rear End Plate Assembly needs replacement, only
install a new Rear End Plate Assembly. Do not use or interchange
old parts with new Rear End Plate Assembly components. The
End Plate, Spacer and Bearing are a matched set. Do not mix
components with those of another set. The Rear Rotor Bearing
is always damaged during removal and a new Rear End Plate
Assembly must be installed.
9. Press the Rear End Plate Assembly onto the shaft of the Controller
Body making certain that the marked end of the Rear Rotor
Bearing faces toward the Controller or rear of the Grinder. Also
make certain that the bevelled side of the Spacer faces the
Cylinder or front of the Grinder.
10. Clean the threads on the Controller Assembly (24) and apply two
or three drops of Loctite No. 277.
Summary of Contents for 77H Series
Page 7: ...Notes...
