SEAL REPAIR
(ON FLAT TOP, BB48X, BB60X, BB72X S/N 1159928 AND BEFORE; BB84X)
(Figure 18)
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.
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.
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.
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.
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)
MAN0632 (5/15/2007)
