Filter
Top Products
MAINTENANCE
INTERSTATER 02/11 Maintenance Section 5-20
© 2011 Alamo Group Inc.
MAINTENANCE
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 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.
Reassembly
1. Use filtered system oil to lubricate all critical moving parts before assembly.
2. Install one snap ring in rear groove of drive shaft. Install one thrust washer, thrust bearing, and second
thrust washer on drive shaft. Install second snap ring in front groove on drive shaft.
3. Replace needle bearing in housing if necessary. Install shaft in housing assembly and install washer. Oil
O.D. of new shaft seal and press into position. Retain with snap ring.
4. Compress pin keeper and install in the spline area of the piston block.
5. Install the three pins in the special grooves of the spline and with head end of pin toward inside of bock.
6. Install one washer, spring, and second washer. Use the two 3/8 I.D. washers and the 3/8 x 3-1/4 cap
screw to compress the spring and retain with snap ring. Remove the 3/8 x 3-1/4 capscrew and two
washers.
7. Install the pivot, spider, and the piston assemblies in the piston block assembly.
8. Lubricate thrust race and install in housing assembly.
9. Install piston block assembly in housing assembly. The piston shoes must contact the thrust race. Be sure
all parts are in their proper position.
10. Install new needle bearing in backplate if necessary.
11. Install new o-ring on backplate.
12. Install backplate on housing.
13. Install six capscrews and torque 15-18 ft. lbs.
14. On through shaft type assembly, install shaft seal and snap ring in backplate. Install key in driveshaft.