ENGINE AR 7C3214 - Caterpillar

Introduction
This Special Instruction contains the procedure for salvaging the piston housing and assembling the thrust washer to the piston housing for certain 740B Articulated Trucks.Do not perform any procedure in this publication or order any parts until you understand the information that is contained in this publication. Machine Piston Housing
Illustration 1 g03646185
Start by machining a flat surface on the outside of the piston housing. A surface grinder can be used. Refer to Illustration 1.Note: Only remove enough material to provide a flat stable surface.
Illustration 2 g03646189
Area to be machined
Position the Piston in a mill or suitable machine tool utilizing the newly machined surface. Refer to Illustration 2.
Illustration 3 g03646214
Measure the thrust surface depth from the legs of the piston housing to determine the correct machining depth. Refer to Illustration 3.
(A) - If measurement is less than 82.75 mm (3.26 inch), machine thrusting surface to 82.5 0.25 mm (3.25 0.01 inch) (to use with a 4 mm (0.16 inch), 444-8152 Washer )
(B) - If measurement is greater than 82.75 mm (3.26 inch), but less than 86.75 mm (3.42 inch), machine thrusting surface to 86.5 0.25 mm (3.41 0.01 inch) (to use with an 8 mm (0.31 inch), 451-1415 Washer )
(C) - If measurement is greater than 86.75 mm (3.42 inch), the housing cannot be salvaged
Machine the thrust surface to the determined dimension in Step 3. Refer to Illustration 2.
Illustration 4 g03646263
(D) 42.5 mm (1.67 inch) (E) 85 mm (3.35 inch) on center (F) 102 mm (4.02 inch) (G) 5.2 mm (0.20 inch) through Holes (x 4)
Lay out and drill four 5.2 mm (0.20 inch) through holes (G). Refer to Illustration 4.
Tap the four drilled Holes (G) to M6X1.
Deburr all machine areas.
Illustration 5 g03646302
Finish by cleaning and protecting all machine surfaces from rust and damage until consumption.
Stamp this Publication Number (REHS9418) on the back side of Housing.Assemble Thrust Washer to Piston Housing
Illustration 6 g03663359
Clean the mating surface of the new machined piston housing (Stamped REHS9418)
Illustration 7 g03663361
Select the proper washer per machine process. 4 mm (0.16 inch) 444-8152 Thrust Washer versus 8 mm (0.31 inch) 451-1415 Thrust Washer . Clean the backside of the thrust washer.
Illustration 8 g03663366
Apply Locktite 620 to the rear of the thrust washer as shown in Illustration 8. 4 mm (0.16 inch) 444-8152 Thrust Washer or 8 mm (0.31 inch) 451-1415 Thrust Washer .
Illustration 9 g03663368
Install the thrust washer. Install four 127-1960 Flat Head Screws . DO NOT apply Locktite 620 to the screw threads.
Illustration 10 g03663370
Torque the four 127-1960 Flat Head Screws to a torque value of 12 3 N m (8.9 2.21 lb ft)
Ensure that the plate is level. Wipe excess Locktite from the internal and external edges of the thrust washer.