18
Dealer Service
MAN1261 (4/11/2018)
Repair to this gearbox is limited to replacing bearings, seals, and gaskets.
Replacing gears, shafts, and a housing is not cost effective. It is more econom
-
ical to purchase a complete gearbox if repair to anything other than replace
-
ment of bearings, seals or gaskets is required.
Fill gearbox with SAE 80W or 90W gear lube until it runs out the side level plug.
Inspect gearbox for leakage and bad bearings.
Leakage is a very serious problem and must be corrected immediately.
Bearing failure is indicated by excessive noise and side to side or end play in
gear shafts.
Seal Replacement
Recommended sealant for gearbox repair is Permatex
®
Aviation 3D Form-A-
Gasket or equivalent.
Leakage can occur at the vertical or horizontal gaskets and shaft seals.
Leakage at the horizontal gasket or seal can be repaired without removing the
gearbox from the cutter.
Seal Installation
NOTE:
Proper seal installation is important. An improperly installed seal will
leak.
1.
Clean area in housing where seal outer diameter (OD) seats. Apply a thin
coat of Permatex.
2.
Inspect area of shaft where seal seats. Remove any burrs or nicks with
an emery cloth.
3.
Lubricate gear shaft and seal lips.
4.
Place seal squarely on housing, spring-loaded lip toward housing. Select
a piece of pipe or tubing with an OD that will sit on the outside edge of the
seal but will clear the housing. Tubing with an OD that is too small will
bow seal cage and ruin seal.
5.
Carefully press seal into housing, avoiding distortion to the metal seal
cage.
Figure 19
.
Seal Installation
Vertical Shaft Seal Replacement
1.
Disconnect and remove the driveline from the gearbox.
2.
Remove breather level plug (24). Figure 18, and siphon gear lube from
housing through this opening.
3.
Remove gearbox stand from mower deck.
4.
Remove gearbox and pulley from gearbox stand.
5.
Remove vertical shaft seal (18). Replace with new seal (see Seal
Replacement, page 18).
Vertical seal should be recessed in housing.
NOTE:
Distortion to seal cage or damage to seal lip will cause seal to
leak.
6.
Fill gearbox with SAE 80W or 90W gear lube until it runs out the level
plug.
7.
Assemble gearbox and pulley to gearbox stand. Attach gearbox stand to
mower deck.
Horizontal Shaft Seal Replacement
1.
Disconnect and remove the driveline from the gearbox.
2.
Remove breather level plug (24), Figure 18, and siphon gear lube from
housing through this opening.
3.
If the leak occurred at either end of horizontal shaft, remove oil cap (20)
and/or oil seal (19). Replace with new one (see Seal Replacement, page
18).
Horizontal seal should be pressed flush with outside of housing.
4.
Fill gearbox with SAE 80W or 90W gear lube until it runs out the level
plug
Gearbox Removal from Mower
Refer to Figure 20.
Figure 20
.
Gearbox Stand Assembly
1.
Disconnect and remove the driveline from the gearbox (1).
2.
Remove breather level plug (2) and siphon gear lube from housing
through this opening.
3.
Remove gearbox stand (3) from mower deck rails by removing four cap
screws (6).
4.
Remove four cap screws (9), flat washer (11), and remove shield (5) from
gearbox.
5.
Remove castle nut (14) and hardware from output shaft of gearbox.
6.
Remove sheave (4) from gearbox.
7.
Remove four bolts (9) that attach gearbox to gearbox stand and remove
gearbox.
1. Seal
2. Pipe or tube
3. Seal seat
4. Casting
Pipe or tube must
press at outer edge of
seal
Incorrect
Installation
7. 5/8NC x 1-3/4 Flange HHCS
8. 5/8NC Flange Lock Nut
9. M8 x 1.25P x 16mm HHCS
11. 5/16 Flat Washer
12. 1/4 x 1/4 x 1-1/4 Key
13. 25 x 44 x 4mm Flat Washer
14. M24 x 2 Castle Nut
15. 3/16 x 2 Cotter Pin
1. Gearbox
2. Breather Level Plug
3. Gearbox Stand
4. Sheave
5. Shield
6. 1/2NC X 2 HHCS