Inspecting Valve Rotators - Navistar INTERNATIONAL DT 466 Service Manual

140
Figure 186 Measuring valve spring tension
5. Use a Valve Spring Compressor (Table 17) to
measure the valve spring tension. Measure the
maximum and minimum lengths of the spring at
the appropriate test loads (valve closed and valve
open). Replace any valve spring that does not
meet valve spring specifications (Table 14).

Inspecting Valve Rotators

1. Clean all valve rotators in a suitable solvent.
Read all safety instructions in the "Safety Information" section of this manual before doing any procedures.
CYLINDER HEAD AND VALVE TRAIN
EGES-265-2
Follow all warnings, cautions, and notes.
© 2009 Navistar, Inc.
Figure 187 Checking valve rotator
1. Ram
2. Steel ball bearing
3. Paint reference line
4. Spring
5. Valve rotator
2. Lubricate the valve rotator with clean engine oil.
Place the valve spring and rotator in spring tester.
3. Place a ball bearing between the valve rotator and
the ram of the spring tester. The ball bearing must
be large enough to prevent the ram from touching
any part of the rotator.
4. Paint a reference line on the valve rotator and
spring.
5. Compress the valve spring rapidly with even
pressure and observe the valve rotator as it turns.
Replace any valve rotator that does not turn.