26
Dealer Service
MAN1289 (10/18/2019)
3.
Remove snap ring (9) and shim (5) from input shaft
(11).
4.
Support gearbox in hand press and push on input
shaft (11) to remove bearing (23).
5.
Remove top cover (4) from housing. Remove gear
(6) from inside housing.
6.
Remove oil seal (10) from front of housing (to be
replaced).
7.
Remove snap ring (9) and shim (5) from front of
housing (1).
8.
Remove input bearing (7) by using a punch and
hammer from outside of housing.
9.
Support housing in vise in a horizontal position.
10.
The castle nut (21), cotter pin (8), and washer (20)
are already removed with the stump jumper/
crossbar. Remove the protective screen (17) and
seal (16).
11.
Remove cotter pin (18), castle nut (12), and
washer (25) from output shaft (19).
12.
Remove output shaft (19) 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 (15) by using a punch and
hammer from the top, outside the housing.
15.
Support housing upside down (top cover surface)
and remove bearing (15) 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.
SEAL REPAIR - BB84.40
(Figure 18)
Vertical Shaft Seal Repair - BB84.40
1.
Disconnect and remove the driveline from the
gearbox.
2.
Remove vent plug (3) and siphon gear lube from
housing through this opening.
3.
Remove crossbar. Hydraulic jack will not operate if
tipped more than 90-degrees. Use care to prevent
bending crossbar during removal. See page See
”Crossbar Removal’ on page 27.
4.
Remove vertical shaft seal (16). Replace with new
seal (See "Seal Installation" on page 23.).
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 Shaft Seal Repair - BB84.40
1.
Disconnect and remove the driveline from the
gearbox.
2.
Remove vent plug (3) and siphon gear lube from
housing through this opening.
3.
If the leak occurred at either end of horizontal shaft
(spindle gearbox), remove oil cap (24) and/or oil
seal (10). For splitter gearbox (Figure 18) use oil
seals (11) and (17). Replace with new one (refer to
Seal Installation, page 23).
4.
Fill gearbox with SAE 80W or 90W gear lube until it
runs out the level plug.
Assemble Gearbox - BB84.40
1.
Clean housing, paying specific attention to areas
where gaskets will be installed.
2.
Wash housing and all components thoroughly.
Select a clean area for gearbox assembly. Replace
all seals, bearings, and gaskets. All parts must be
clean and lightly oiled before reassembling.
3.
Insert output bearings (15) in the housing, using a
round tube of the correct diameter and a hand
press.
4.
Slide output shaft (19) through both bearings (15)
until it rests against bearing (6).
5.
Slide shim (5) over output shaft (19).
6.
Press gear (13) onto output shaft (19) and secure
with washer (25), castle nut (12), and cotter pin
(18).
7.
Apply grease to lower seal lips (16) and press seal
(16) over output shaft (19), using a tube of the
correct diameter. Be sure not to damage the seal
lip.
Press in housing so that seal is recessed. Install
protective screen (17) and position it together with
dual lip seal (16) by pressing it into position. Verify
that snap ring is seated correctly.
8.
Press bearing (7) into the housing, using a round
tube of the correct diameter and a hand press.
Secure with shim (5) and snap ring (9).
9.
Secure snap ring (9) on input shaft (11) if not
already secure.
