Loader Bobcat 773. Manual - part 49

HYDROSTATIC PUMP (Cont’d)

Inspection (Cont’d)

NOTE: DO NOT use sandpaper or a file to remove

scratches.

Check each piston in its bore. The piston must move
freely [A].

Check each piston shoe for wear or scratches.

Inspect the spherical washer for wear or damage [B].

Check the pins for wear and all are the same length [C].

If there is any defect in the rotating group, the complete
unit must be replaced.

Check the shaft splines for damage.

Replace the defective parts as needed.

Support the seal carrier, use the correct size driver tool to
remove and install the seal [D].

A

CD–10777

C

CD–10779

D

CD–10780

773 BICS Loader

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Service Manual

B

CD–10778

HYDROSTATIC PUMP (Cont’d)

Inspection (Cont’d)

Support the trunnion cover, use the correct size driver tool
to remove and install the lip seal [A].

Check the bearing in the pump housing end cap. If the
bearing is worn, use the correct size driver tool to remove
and install the bearing [B].

Swashplate Pre–Load

Install the bearing spacer and cup into the housing with
no shims (both sides).

Install the trunnion covers. Install the bolts and tighten to
18–22 ft.–lbs. (24–30 Nm) torque.

Install the magnetic base dial indicator as shown [C].

Move the swashplate back and forth by hand.

Add shims, under the bearing spacers, to provide
0.002–0.004 inch (0,05–0,10 mm) pre–load on the
bearings.

EXAMPLE: If the dial indicator reads 0.040 inch (10,2
mm) end play. Shim thickness of 0.042–0.044 inch
(10,7–11,2 mm) should be installed between the bearing
spacers and cups. See Parts Microfiche for correct shim
thickness.

Remove the trunnion cover. Remove the bearing
spacers.

Install the correct amount of shims. Locate the shims so
that there is no more than 0.008 inch (0,20 mm) difference
in shim thickness from one side to the other. Install the
bearing spacers and trunnion covers.

NOTE: When the correct amount of shims are

installed, apply a torque of 5–20 in.–lbs.
(0,6–2,3 Nm) to the swashplate shaft to move
the swashplate.

Color or Shim & Value

Green – 0.003 inch (0,076 mm)
Blue – 0.005 inch (0,127 mm)
Brown – 0.010 inch (0,25 mm)
Yellow – 0.020 inch (0,51 mm)

NOTE: Later model pumps, shims are not used, the

swash plate pre–load test procedure and
bearing clearance is the same.

A

CD–10781

C

CD–12461

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773 BICS Loader

Service Manual

773 Service Manual #6900092–Hydrostatic System Section Part 2 of 3

B

CD–10782

DRIVE BELT HOUSING

Removal And Installation

Remove the engine/hydrostatic pump assembly from the
loader. (See Page 7–1.)

Remove the three drive belt shield mounting clips (Item
1) [A].

Remove the belt shield (Item 2) [A] from the belt shield
housing.

Loosen the drive belt tensioner bolt (Item 1) [B] from the
housing and remove the drive belt.

Installation: Tighten the bolt to 25–28 ft.–lbs. (34–38
Nm) torque.

Adjust the drive belt. (See Page 1–1.)

Remove the eight flywheel mounting bolts (Item 1) [C]
and remove the engine flywheel.

Installation: Apply engine oil to the threads and seats
before tightening. Tighten the mounting bolts to 72–80
ft.–lbs. (98–108 Nm) torque.

Remove the four mounting bolts (Item 1) [D] which fasten
the housing on the engine.

Installation: Tighten the mounting bolts to 35–40 ft.–lbs.
(48–54 Nm) torque.

Remove the bolt (Item 2) [D] which fasten the two drain
hoses to the housing.

Installation: Tighten the mounting bolts to 60–65 ft.–lbs.
(82–88 Nm) torque.

Remove the starter (Item 3) [D] from the drive belt
housing. (See Page 6–1.)

Revised Jan. 99

P–04230

A

1

1

2

C

P–04234

1

D

P–04233

3

1

2

773 BICS Loader

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Service Manual

B

P–04223

1

DRIVE BELT HOUSING (Cont’d)

Removal And Installation (Cont’d)

Remove the hydrostatic pump drive pulley mounting nut
(Item 1) [A] and washer.

Installation:  Tighten the mounting nut to 175–200
ft.–lbs. (237–271 Nm) torque.

Install a puller on the drive pulley and remove the pulley
from the hydrostatic pump shaft [B].

Installation:  Install the pulley key in the shaft before
installing the drive pulley.

Remove the two mounting bolts (Item 1) [C] from the drive
belt housing which mount the hydrostatic pump to the
housing.

Installation: Tighten the mounting bolts to 65–70 ft.–lbs.
(88–95 Nm) torque.

Remove the drive belt tensioner (Item 2) [C] from the
drive belt housing. (See Page 3–53 & 3–58.)

Remove the mounting bolt (Item 1) [D] from engine
coolant tubeline mounting bracket which is attached to
the belt shield housing.

Installation:  Tighten the mounting bolt to 25–28 ft. lbs.
(34–38 Nm) torque.

Remove the blower fan drive belt tensioner assembly
(Item 2) [D] from the housing.

Remove the drive belt housing.

Reverse the removal procedure to install the drive belt
housing.

A

P–04236

1

C

P–04238

2

1

D

P–04231

1

2

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773 BICS Loader

Service Manual

B

P–04235