MBW R422 - Manual (Page 12)

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Breather Removal
1. Remove the hex head cap screw (#28) from the top
of the breather assembly (#14).
2. Remove the plain washer (#29), cap (#17) and filter
(#15).
3. Use a pipe wrench to remove the breather tube (#16).
CAUTION
Do not disassemble the breather assembly.
Slide Bearing Removal
1. Remove the retaining ring (#23) from the bottom of
the gearbox guide tube.
2. Pull the slide bearing (#25) out the bottom of the gear
box guide tube.
CAUTION
Do not scratch or gouge the gearbox guide tube
walls.
Bellows Removal
Refer to Lower Unit Assembly, page 16.
1. Loosen the four hex head flange screws (#20)
securing the upper bellows ring (#7) to the gearbox.
2. Slide the bellows assembly off the gearbox.
3. Remove upper & lower bellows rings (#7 & #2) from
bellows (#4).
Gearbox Assembly
Refer to Gearbox Assembly, page 14.
1. Press the small ball bearing (#22) into the gearbox
from the back. Secure with a retaining ring (#18).
2. Press the large ball bearing (#2) into the gearbox
from the back. Secure with a retaining ring (#10).
3. Press a new oil seal (#11) into the gearbox. Make
sure the oil seal is pressed in straight.
4. Lightly oil the lip of the oil seal and the shaft portion of
the pinion (#21). Carefully press the pinion into the
gearbox.
CAUTION
Do not use excessive pressure to seat the pinion.
5. Install a retaining ring (#4) onto the pinion from inside
the gearbox.
6. Press the needle bearing (#6) into the gearbox. The
bearing must be pressed in with the numbers and
letters facing up. Apply a light coat of oil (see Fluid
Levels, page 5 for proper oil type) to the needle
bearing after installation.
7. Place a retaining ring (#10) over the large shaft of the
crank gear (#20). Press the ball bearing (#2) onto the
crank gear.
8. Install a retaining ring (#1) to secure the ball bearing
to the crank gear shaft.
9. Press the bearing (#3) into the connecting rod (#5)
and secure with a retaining ring (#8).
10. Press the connecting rod (#5) onto the offset shaft of
the crank gear (#20).
11. Install a retaining ring (#9) to secure the connecting
rod.
12. Press the crank gear assembly into the gearbox.
Install the snap ring (#10) using a retaining ring pliers
inserted through the slot in the crank gear.
13. Install the SAE plug (#19) into the gearbox. Do not
over tighten.
14. Replace the breather tube sub-assembly (#16), filter
(#15), cap (#17), and plain washer (#29). Apply
medium strength thread locking liquid to the threads
of the hex head cap screw (#28) and install.
15. Slide the slide bearing (#25) with the holes up into the
gearbox tube and align the hole in the bearing with
the access hole in the gearbox.
16. Secure slide bearing in place with internal retaining
ring (#24).
17. Assemble the lower bellows ring (page 16, #3) to one
side of the bellows (page 16, #5).
18. Assemble the upper bellows ring (page 16, #8) to the
other side of the bellows.
19. Insert four hex head flange screws (page 16, #20)
through the upper bellows mount so the head of the
screw is wedged between the bellows and the upper
bellows mount.
20. Slide the bellows assembly over the gearbox guide
tube (page 18, #4) with the upper bellows ring toward
the gearbox.
21. Thread the hex head flange screws into the gearbox
to secure the bellows.
22. Apply a light coat of oil (see Fluid Levels, page 5 for
proper oil type) to all bearings after installation is
complete.
Lower Unit Disassembly
NOTE: The lower unit can be separated from the drive
unit (engine, gearbox and handle) without completely
disassembling the rammer. If the lower unit has not
already been separated, follow the “Gearbox
Removal” instructions.
Refer to Lower Unit Assembly, page 16.