Dealer Service
25
MAN0632 (5/15/2007)
SEAL REPAIR
(ON FLAT TOP, BB48X, BB60X, BB72X
S/N 1159928 AND BEFORE; BB84X)
(Figure 18)
Vertical Shaft Seal Repair
1.
Disconnect and remove the rear driveline from the
gearbox.
2.
Remove vent plug (27) and siphon gear lube from
housing through this opening.
3.
Remove crossbar (see
Crossbar Removal, page
31
).
4.
Remove vertical shaft seal (21). Replace with new
seal (see
Seal Installation, page 24
).
Vertical seal should be recessed in housing. Hori
-
zontal seal should be pressed flush with outside of
housing.
NOTE:
Distortion to seal cage or damage to seal
lip will cause seal to leak.
5.
Fill gearbox with SAE 80W or 90W gear lube until it
runs out the level plug.
6.
Remove and replace any seal damaged in
installation.
Horizontal Seal Leak Repair
1.
Disconnect and remove the rear driveline from the
gearbox.
2.
Remove vent plug (27) and siphon gear lube from
housing through this opening.
3.
If the leak occurred at either end of horizontal shaft,
remove oil cap (23) and/or oil seal (22). Replace
with new one (refer to
Seal Installation, page 24
).
4.
Fill gearbox with SAE 80W or 90W gear lube until it
runs out the level plug.
GEARBOX REPAIR
(ON FLAT TOP, BB48X, BB60X, BB72X
S/N 1159928 AND BEFORE; BB84X)
(Figure 18)
NOTE:
Repair to this gearbox is limited to replacing
bearings, seals, and gaskets. Replacing gears, shafts,
and a housing is not cost effective. Purchasing a com
-
plete gearbox is more economical.
Remove Gearbox from Cutter
1.
Disconnect and remove the rear driveline from the
gearbox.
2.
Remove vent plug (27) and siphon gear lube from
housing through this opening.
3.
Remove cotter pin, washer, and nut from vertical
shaft and remove crossbar (see
Crossbar
Removal, page 31
).
4.
Remove the four bolts that attach gearbox to cutter
and remove gearbox.
Disassemble Gearbox
1.
Remove 3/8" plug from side of gearbox and pour
out gear oil.
2.
Remove oil cap (23) (to be replaced).
3.
Remove snap ring (12) and shim (15) from input
shaft (3).
4.
Support gearbox in hand press and push on input
shaft (3) to remove bearing (9) and spacer (14).
5.
Remove top cover (25) from housing. Remove
gear (1) from inside housing.
6.
Remove oil seal (22) from front of housing (to be
replaced).
7.
Remove snap ring (12) and shim (15) from front of
housing (2).
8.
Remove input bearing (8) by using a punch and
hammer from outside of housing.
9.
Support housing in vise in a horizontal position.
10.
The castle nut (17), cotter pin (28), washer (18),
and hub (24) are already removed with the stump
jumper/crossbar. Remove the snap ring (10),
washer (19), and seal (21).
11.
Remove cotter pin (11), castle nut (16), and washer
(20) from output shaft (4).
12.
Remove output shaft (4) by using a punch and
hammer and tap on top to drive down.
13.
Remove gear (5) and shim (15) from inside
housing.
14.
Remove bearing (7) by using a punch and hammer
from the top, outside the housing.
15.
Support housing upside down (top cover surface)
and remove bearing (6) by using a punch and
hammer from the bottom side of the housing.
16.
Inspect gears for broken teeth and wear. Some
wear is normal and will show on loaded side.
Forged gear surfaces are rough when new. Check
that wear pattern is smooth.
17.
Inspect vertical and horizontal shafts for grooves,
nicks, or bumps in the areas where the seals seat.
Resurface any damage with emery cloth.
18.
Inspect housing and caps for cracks or other
damage.
(Rev. 5/11/2010)
