784C, 785C and 785C HAA Off-Highway Truck/Tractors Power Train Caterpillar

Illustration 1	g00908875

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

Type of pump: Gear

Lubricate the pump with oil before you operate the pump.

Bench test requirements: SAE 10W oil must be stabilized at 52° ± 3°C (125° ± 5°F) before the test is performed.

(A) Transmission scavenge section

Minimum output ... 165 L/min (44 US gpm)

Test pressure ... 345 kPa (50 psi)

Test speed of pump ... 900 rpm

(B) Transmission lubrication section

Minimum output ... 95 L/min (25 US gpm)

Test pressure ... 345 kPa (50 psi)

Test speed of pump ... 1800 rpm

(C) Transmission charging section

Minimum output ... 148 L/min (39.1 US gpm)

Test pressure ... 3100 kPa (450 psi)

Test speed of pump ... 1800 rpm

(1) Clearance between a new gear and a new body ... 0.081 ± 0.021 mm (0.0032 ± 0.0008 inch)

(2) Clearance between a new gear and a new body ... 0.104 ± 0.043 mm (0.0041 ± 0.0017 inch)

(3) Clearance between a new gear and a new manifold ... 0.168 ± 0.043 mm (0.0066 ± 0.0017 inch)

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

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

Diameter of the bores in the pump body ... 31.786 ± 0.008 mm (1.2514 ± 0.0003 inch)

Illustration 2	g00909129
Section A-A

(D) Depth of the bearing ... 1.575 mm (0.062 inch)

(E) Position of the bearing joint ... 30° ± 15° from the centerline

Illustration 3	g00909131
Section B-B

(F) Position of the dowel ... 5.0 ± 0.5 mm (0.197 ± 0.0197 inch)

Illustration 4	g00909132
Section C-C

(E) Position of the bearing joint ... 30° ± 15° from the centerline

(G) Depth of the bearing ... 1.5 ± 0.25 mm (0.059 ± 0.0098 inch)

Illustration 5	g00909133
Section D-D

(H) Position of the dowels ... 4.83 mm (0.19 inch)

Illustration 6	g00909134
Section E-E

(E) Position of the bearing joint ... 30° ± 15° from the centerline

(J) Depth of the bearing ... 1.6 mm (0.063 inch)