Alamo none manual Cuttershaft Replacement Cont’d, Hydraulic Motor Disassembly, Inspection

MAINTENANCE

MAINTENANCE

CUTTERSHAFT REPLACEMENT (Cont’d)

HYDRAULIC MOTOR DISASSEMBLY

1.Clean outside of unit thoroughly. Refer to Hydraulic Motor illustration in the Parts Listing section.

2.Clamp shaft in a protected jaw vise with backplate end up.

3.Remove six cap screws from backplate.

4.Use a plastic mallet and tap the backplate to loosen it - then remove.

5.Remove o-ring from backplate.

6.Remove the complete piston block assembly from the housing assembly.

7.Remove piston assemblies, spider, and pivot from piston block assembly.

8.The piston block assembly need not be disassembled unless the pins or spring is damaged.

The following procedure should be used if the spring is to be removed from the piston block. The spring is highly compressed and the snap ring should not be removed without compressing the spring.

The following parts will be needed to disassemble the piston block:

2 ea. 3/8 I.D. X. 1-1/8 O.D. flat washer 1 ea. 3/8 I.D. X. 3-1/4 N.C. capscrew 1 ea. 3/8 N.C. nut

Place one of the flat washers over the 3/8 x 3-1/4 capscrew and place this through the center of the piston block. Place the other washer over the capscrew and let it rest on the three pins. Screw nut on and compress the spring inside the piston block. Use a pair of snap ring pliers and remove the internal snap ring. Remove the bolt and two washers. Remove the two washers, spring, three pins, and pin keeper.

9.Remove thrust race from housing.

10.Remove snap ring from housing.

11.Remove shaft seal from housing.

12.Remove washer from housing.

13.Remove drive shaft from housing.

14.Remove the two snap rings, thrust washers, and thrust bearing, from drive shaft.

INSPECTION

1.Wash all parts thoroughly in a suitable solvent.

2.Examine needle bearings in housing and backplate.

3.Inspect thrust washers and thrust bearing. All surfaces should be free of any signs of wear or fretting.

4.Inspect spider and pivot; conical surfaces should be free of wear and score marks.

5.Inspect the pistons: the O.D. surface should be smooth and free of scoring. The shoes should be snug to fit to the piston. The face of the shoes should be flat and free of scoring and flaking. DO NOT LAP PISTON SHOES.

6.Inspect the piston block; the bores should be free of scoring. The surface that contacts the backplate should be smooth and free of grooves or metal build-up. DO NOT LAP PISTON BLOCK.

7.Inspect the thrust race; the surface should show no signs of scoring or grooves.

8.Inspect the flat surface on the backplate; it should be free of excessive scoring or metal build-up. DO NOT LAP BACKPLATE.

9.Inspect the drive shaft for fretting in the bearing areas. Check spline area for twisted or broken teeth. If keyed shaft, check for cracked or chipped keyway.

GRASS KING 03/09 Maintenance Section 5-10

© 2009 Alamo Group Inc.