797 Off-Highway Truck Power Train Caterpillar

Illustration 1	g00578535

Rotation of the pump is clockwise when the pump is viewed from the drive end.

Type of pump: Gear

Lubricate the pump before you operate the pump.

The pump must rotate freely with your hand before the pump is assembled to the rear axle housing. Also, the pump must rotate freely with your hand after the pump is assembled to the rear axle housing.

Bench test requirements: SAE 10W oil must be stabilized at 52° ± 3°C (125.6° ± 5.4°F) before the test is performed.

(A) Gear pump for differential sump scavenge

Minimum output ... 90 L/min (24 US gpm)

Test pressure ... 690 kPa (100 psi)

Test speed of the pump ... 900 rpm

(B) Gear pump for lubrication of the differential

Minimum output ... 56 L/min (15 US gpm)

Test pressure ... 690 kPa (100 psi)

Test speed of the pump ... 900 rpm

(C) Gear pump for lubrication of the final drive

Minimum output ... 66 L/min (17 US gpm)

Test pressure ... 690 kPa (100 psi)

Test speed of the pump ... 900 rpm

(1) Dimensions of new shafts and of new pump bodies

Dimensions of the drive shaft and diameter of the driven shaft ... 31.742 ± 0.005 mm (1.2497 ± 0.0002 inch)

Diameter of the bearings in the pump body ... 31.799 ± 0.008 mm (1.2519 ± 0.0003 inch)

(2) Clearance between a new gear and a new cover ... 0.124 ± 0.028 mm (0.0049 ± 0.0011 inch)

(3) Clearance between a new gear and a new body ... 0.120 ± 0.021 mm (0.0047 ± 0.0008 inch)

(4) Clearance between a new gear and a new cover ... 0.120 ± 0.043 mm (0.0047 ± 0.0017 inch)