MBW MM120 - Manual (Page 16)

- 13 -
Engine & Gearbox Disassembly
Refer to Gearbox Drive Assembly, page 18.
1. Remove engine and gearbox from mixer. See Engine
& Gearbox Removal, page 12.
2. Remove the access cover (#13) which is secured by
four bolts (#15).
3. Remove the two bolts (#14) and lock washers (#18)
and loosen the two set screws (#17) from the clutch
yoke (#7). Clutch must be disengaged to gain access
to bolts.
4. Remove retaining ring (#3) on yoke shaft (#11).
5. Slide shaft out of gearbox and remove clutch yoke.
6. While maintaining support of gearbox, remove four
bolts (#16) securing gearbox (#6) to engine adapter
plate (#10).
7. Slide engine and clutch out from inside gearbox.
8. Loosen two bolts on clutch body to remove from
engine crankshaft.
Engine & Gearbox Assembly
Refer to Gearbox Drive Assembly, page 18.
1. Assemble bushing (#2) and key (#8) to engine crank-
shaft.
2. Bolt adapter plate (#10) to engine (#1).
3. If clutch (#9) is not disengaged (popped out), pry
throw-out bearing away from adjusting plate to disen-
gage it.
4. Slide disengaged clutch (#9) onto crankshaft. Be
sure that clutch pilot bearing is bottomed out in clutch
body, and leave a clearance of 0.030” - 0.060” be-
tween bearing and crankshaft. Tighten clutch bolts al-
ternately, and apply a final torque of 23 lb-ft.
5. Slide gearbox (#6) onto engine. Rotate gearbox while
assembling to line up spline shafts.
6. Install four bolts (#16) and tighten gearbox in place.
7. Apply grease to forks of clutch yoke (#7), and place
inside housing on top of clutch pins.
8. Slide yoke shaft (#11) into housing and through yoke.
9. Install retaining ring (#3) onto shaft.
10. Bolt yoke to shaft using two bolts (#14) and lock
washers (#18) and tighten set screws (#17) in yoke.
11. Install access cover (#13) using four bolts (#15).
Gearbox Disassembly
Refer to Gearbox Assembly, page 22.
1. Disassemble gearbox from engine before continuing.
See Engine & Gearbox Disassembly, page 13.
2. Support gearbox so it stands upright. Remove
magnetic drain plug (#6) and drain oil.
3. Tip gearbox down onto a support so clutch housing
faces down.
4. Remove sprocket from output shaft. Use a puller if
necessary.
5. Remove all 11 bolts (#27) and nuts (#28) from
gearbox perimeter.
6. Lightly tap gearbox cover and pull it straight up to
remove from housing.
7. Simultaneously lift up on all three large gears until the
bearings are free from the housing. Then slide gears
apart from one another and remove from housing.
8. Remove retaining ring (#3) securing input shaft (#11).
9. Remove input shaft by pulling straight up.
10. Remove both seals (#22 & #23) from housing and
cover.
The following steps are only necessary if bearings or gears
need to be replaced.
CAUTION
Always replace any bearings which are removed
with a bearing puller.
11. Press bearing (#26) off of input shaft (#11). NOTE: Al-
ways support bearings by inner race when pressing
off of or onto shafts.
12. Using a bearing puller, remove both bearings (#1)
from pinion shaft (#10).
13. Remove retaining ring (#20) from shaft.
14. Press gear (#14) off of shaft and remove key (#2).
15. Pull both bearings (#5) off of pinion shaft (#9).
16. Remove retaining ring (#19) from shaft.
17. Press gear (#13) off of shaft and remove key (#24).
18. Pull both bearings (#17) off of output shaft (#15).
19. Remove retaining ring (#21) from shaft.
20. Press gear (#12) off of shaft and remove key (#18).
Inspect all keys and replace if they look worn or
damaged.
Gearbox Assembly
Refer to Gearbox Assembly, page 22.
1. Press bearing (#26) onto input shaft (#11). NOTE: Al-
ways support bearings by inner race when pressing
onto or off of shafts.
2. Install key (#2) into pinion shaft (#10).
3. Press gear (#14) onto shaft and install retaining ring
(#20).