Loader Bobcat 773. Manual - part 95

TIMING GEARS

Checking Backlash

When the gears are installed, check the backlash of the
gears.

Install a dial indicator [A].

Hold one gear while turning the other gear [A].

If the backlash exceeds the allowable limit, check the oil
clearance of the shaft and gear. If the oil clearance is
correct, replace the gear.

Crank Gear &
  Idler Gear

0.002–0.004 inch (0,042–0,112 mm)

. . . . . . 

Allowable Limit

0.006 inch (0,15 mm)

. . . . . . . . . . . . . . . . 

Cam Gear &
  Idler Gear

0.002–0.005 inch (0,042–0,115 mm)

. . . . . . 

Allowable Limit

0.006 inch (0,15 mm)

. . . . . . . . . . . . . . . . 

Injection Pump Gear &
  Idler Gear

0.002–0.005 inch (0,042–0,115 mm)

. . . . . . 

Allowable Limit

0.006 inch (0,15 mm)

. . . . . . . . . . . . . . . . 

Oil Pump Gear &
  Idler Gear

0.002–0.004 inch (0,042–0,109 mm)

. . . . . 

Allowable Limit

0.002 inch (0,15 mm)

. . . . . . . . . . . . . . . . 

A

PI–10005

773 BICS Loader

–7–59–

Service Manual

FUEL CAMSHAFT

Removal And Installation

Remove the timing gearcase cover. (See Page 7–54.)

Remove the idler gear. (See Page 7–56.)

Remove the bolt (Item 1) [A] from the retainer plate (Item
2) [A].

Installation:  Tighten the bolt to 60–72 in.–lbs. (6,8–8,1
Nm) torque.

Remove the fuel camshaft retainer plate (Item 2) [A].

Remove the fuel camshaft and fork lever assembly (Item
1) [B] at the same time.

Governor

The governor serves to keep the engine speed constant
by automatically adjusting the amount of fuel supplied to
the engine according to changes in the load.

Disassemble and assemble the governor and fuel
camshaft as shown in figure [C].

Check all the parts for wear or damage and replace as
needed.

A

B–14342

2

1

C

PI–10008

12

9

13

11

10

7

6

8

4

5

1

3

2

  1. Start Spring
  2. Governor Spring
  3. Governor Spring
  4. Fork Lever
  5. Fork Lever
  6. Fork Lever Shaft
  7. For Lever Holder
  8. Governor Lever
  9. Fuel Camshaft
10. Governor Ball Case
11. Steel Balls
12. Governor Sleeve
13. Steel Ball

–7–60–

773 BICS Loader

Service Manual

B

B–14343

1

CRANKSHAFT GEAR

Removal And Installation

Remove the timing gearcase cover. (See Page 7–54.)

Remove the idler gear. (See Page 7–56.)

Remove the crankshaft gear with a puller [A].

Remove the crankshaft key.

Installation: Install the crankshaft key. Heat the
crankshaft gear to 176

°

F (80

°

C) and fit it on the

crankshaft.

OIL PUMP

Removal And Installation

Remove the timing gearcase cover. (See Page 7–54.)

Remove the crankshaft gear.

Remove the nut from the oil pump shaft. Use a puller to
remove the oil pump gear (Item 1) [B].

Installation:  Tighten the nut on the oil pump shaft to
46–54 ft.–lbs. (62–73 Nm) torque.

Remove the oil pump mounting bolts. Remove the oil
pump (Item 2) [B].

Installation:  Tighten the oil pump mounting bolts to
60–72 in.–lbs (6,9–8,1 Nm) torque.

Oil Pump Service

Measure the clearance between the lobes of the inner
rotor and outer rotor [C].

Measure the clearance between the outer rotor and pump
body [D].

If the clearance exceeds the allowable limit, replace the
oil pump.

Clearance Between Inner &
  Outer Rotor

0.004–0.006 inch (0,10–0,16 mm)

. . . . . . 

Allowable Limit

0.008 inch (0,2 mm)

. . . . . . . . . . . . . . . . . 

Clearance Between Outer Rotor
  & Body

0.004–0.008 inch (0,11–0,19 mm)

. . . . . . . . . . 

Allowable Limit

0.010 inch (0,25 mm)

. . . . . . . . . . . . . . . . 

A

B–03686

C

B–03616

D

A–02732

773 BICS Loader

–7–61–

Service Manual

B

B–03658

1

2

OIL PUMP (Cont’d)

Oil Pump Service (Cont’d)

Put a piece of press gauge on the rotor face [A].

Install the cover and tighten the bolts.

Remove the cover carefully. measure the width of the
press gauge [A].

If the clearance exceeds the allowable limit, replace the
oil pump.

End Clearance

0.004–0.006 inch (0,11–0,15 mm)

. . . . . 

Allowable Limit

0.008 inch (0,2 mm)

. . . . . . . . . . . . . . . . . 

Checking Engine Oil Pressure

Remove the oil pressure sensor.

Install a pressure gauge [B].

Start the engine and run until it is at operating
temperature.

If the oil pressure is less than the allowable limit, check the
following items:

* Engine Oil Level Low
* Oil Pump Defective
* Oil Galley Plugged
* Oil Strainer Plugged
* Excessive Clearance at the Rod & Main Bearings
* Relief Valve Stuck

At Idle Speed Allowable Limit

7 PSI (49 kPa)

. . . . . . . . 

At Rated Speed

43–65 PSI (294–441 kPa)

. . . . . . . . . . . 

Allowable Limit

36 PSI (245 kPa)

. . . . . . . . . . . . . . . . . . . 

Relief Valve

The relief valve prevents damage of the lubricating
system due to high pressure. This relief valve is a ball
type.

Remove the valve seat (Item 2), [C] ball (Item 3) [C] and
spring (Item 1) [C].

Check the parts for wear or damage and replace as
needed.

A

PI–10009

C

PI–10011

3

2

1

–7–62–

773 BICS Loader

Service Manual

B

PI–10010