Dealer Service
29
MAN1313 (3/3/2021)
Disassemble Gearbox (Figure 24)
1.
Remove top cover (22) from housing. Turn gearbox
upside down and pour out remaining gear oil from
gearbox.
2.
Remove oil cap (20) (to be replaced).
3.
Remove snap ring (10) and shim (13) from input shaft
(3).
4.
Support gearbox in hand press and push on input
shaft (3) to remove bearing (7).
5.
Remove gear (1) from inside housing.
6.
Remove oil seal (19) from front of housing (to be
replaced).
7.
Remove snap ring (10) and shim (13) from front of
housing (2).
8.
Remove input bearing (27) by using a punch and
hammer from outside of housing.
9.
Support housing in vise in a horizontal position.
10.
The castle nut (15) and cotter pin (25) are already
removed with the drive sheave. Remove snap ring
(21), washer (8), and seal (18).
11.
Remove cotter pin (9), castle nut (14), and washer
(17) 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 (16) from inside
housing.
14.
Remove bearing (26) 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.
Vertical Shaft Seal Replacement (Figure
24)
1.
Disconnect and remove the driveline from the
gearbox.
2.
Remove vent/dipstick (24) and siphon gear lube
from housing through this opening.
3.
Remove gearbox stand from mower (see Remove
Gearbox from Mower, page 28).
4.
If the leak occurred at the vertical shaft, remove
vertical shaft oil seal (18). Replace with new seal
(see Seal Replacement, page 26).
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.
Assemble gearbox and pulley to gearbox stand.
Attach gearbox stand to mower deck.
Reassemble Gearbox (Figure 24)
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.
1.
Clean housing, paying special attention to areas
where seals will be installed.
2.
Wash housing and component thoroughly. Select a
clean area for gearbox assembly. Replace all seals
and bearings. All parts must be clean and lightly
oiled before reassembling.
3.
Insert output bearings (6 & 26) in the housing,
using a round tube of the correct diameter and a
hand press.
4.
Slide output shaft (4) through both bearings (6 &
26) until it rests against bearing (6).
5.
Slide shim (16) over output shaft (4).
6.
Press gear (5) onto output shaft (4) and secure
with washer (17), castle nut (14), and cotter pin (9).
7.
Apply grease to lower seal lips (18) and press seal
over output shaft (4), using a tube of the correct
diameter. Be sure not to damage the seal lip. Press
in housing so that seal is recessed.
8.
Insert protective washer (8) by hand. Install snap
ring (21) and position it together with dual lip seal
(18) by pressing it into position. Verify that snap
ring is seated correctly.
9.
Press bearing (7) into the housing, using a round
tube of the correct diameter and a hand press.
Secure with shim (13) and snap ring (10).
10.
Secure snap ring (11) on input shaft (3) if not
already secure.
11.
Place gear (1) through top of housing and align
gear (1) and gear (5) so that gear teeth are a
match.
12.
While holding gear (1) in place, slide input shaft (3)
through gear (1) and bearing (7). Align splines on
shaft (3) and gear (1).
