Rocker Arm Assemblies Replacement

TM 9-2320-363-34-1 · Chapter 3 — Power Package Maintenance

This task covers: a. Removal b. Cleaning c. Inspection d. Installation e. Adjustment

Tools and Special Equipment:                         Equipment Condition:

Shop Equipment, SC 4910-95-CL-A31                    Reference              Condition Description
Tool Kit, SC 5180-90-CL-N05
Rocker Arm Lifter, J35996                            Page 3-129             Engine Retarder Removed
Rocker Stud Socket, J36003
Injector Timing Height Gauge, J35637-A (DDEC         General Safety Instructions:
II)
Injector Timing Height Gauge, J39697 (DDEC Ill)
Valve Button Expander, J36347
Cup Plug Installer, J36326

Materials/Parts:

Plug, Cup (2)        P/N 9421745
Rags                 Appendix B, Item 48
Solvent, Drycleaning Appendix B, Item 20
Oil, Lubricating     Appendix B, Item 37

1. IN ONE-TURN INCREMENTS, REMOVE SIX RETAINING BOLTS (1) AND SIX SADDLE SPACERS (2).

2. REMOVE TWO NUTS (3) AND TWO SADDLE SPACERS (4).

Position lifter fingers under cross arch of exhaust rocker arm assembly (above center section of injector rocker assembly). Lifter fingers fit between intake and injector rockers. Tag rocker arm assemblies by cylinder location prior to removal to aid in installation.

3. USING ROCKER ARM LIFTER (5) ON ROCKER ARM ASSEMBLIES (6) FROM CAM ROLLER SIDE, LIFT ROCKER ARM ASSEMBLIES AND ROCKER ARM SHAFT (7) FROM CYLINDER HEAD.

4. SLIDE ROCKER ARM ASSEMBLIES (6) OFF ROCKER ARM SHAFT (7).

5. REMOVE JAM NUTS (8) AND ADJUSTING SCREWS (9) FROM EACH ROCKER ARM ASSEMBLY (6).

6. HOLD ADJUSTING SCREW (9) AND WITH VALVE BUTTON EXPANDER (10) SPREAD LEGS OF RETAINING CLIP (11) AND REMOVE INTAKE VALVE BUTTON (12).

7. REMOVE RETAINING CLIP (11) FROM THREADED END OF ADJUSTING SCREW (9).

8. USING PIN PUNCH, PUNCH HOLE IN TWO CUP PLUGS (13) AT ENDS OF ROCKER ARM SHAFT (7). PRY TWO CUP PLUGS (13) FROM SHAFT (7). DISCARD CUP PLUGS.

1. SOAK ROCKER ARM SHAFT (1) IN DRYCLEANING SOLVENT. RUN WIRE BRUSH THRU CENTER OIL PASSAGE (2).

To prevent injury, compressed air will not exceed 30 psi (207 kPa). Use only with effective chip guarding and personal protective equipment, goggles, shield, and gloves.

2. BLOW OUT CENTER OIL PASSAGE (2) AND OIL HOLES (3) WITH COMPRESSED AIR. WIPE EXTERIOR WITH CLEAN, LINT-FREE RAGS.

1. INSPECT ROCKER ARM SHAFT (1) WHERE CONTACT IS MADE WITH ROCKER ARM BUSHINGS (2). IF ROCKER ARM SHAFT (1) DIAMETER IS LESS THAN 1.415 IN. (35.943 mm) MINIMUM, REPLACE SHAFT.

2. INSPECT ROCKER ARM BUSHINGS (2) FOR EXCESSIVE WEAR OR SCORING. MEASURE ROCKER ARM BUSHING (2) INSIDE DIAMETER. IF DIAMETER IS MORE THAN 1,4191 IN. (36.050 mm), REPLACE ROCKER ARM ASSEMBLY.

3. CHECK CAM FOLLOWER ROLLERS (3) FOR SCORING, PITTING, OR FLAT SPOTS. IF ANY OF THESE CONDITIONS ARE EVIDENT, REPLACE ROCKER ARM ASSEMBLY (4).

4. CHECK SIDE CLEARANCE BETWEEN ROLLER AND ROCKER ARM. IF MORE THAN 0.03 IN. (0.08 mm) MAXIMUM, REPLACE ROCKER ARM ASSEMBLY (4).

5. MAKE SURE CAM FOLLOWER ROLLER (3) TURNS FREELY ON ITS PIN. REPLACE ROCKER ARM ASSEMBLY (4) IF ROLLER DOES NOT TURN FREELY OR BINDS, OR IF THERE IS VERTICAL MOVEMENT BETWEEN ROLLER AND PIN.

6. CHECK ROCKER SHAFT ARM STUD FOR TIGHTNESS WHENEVER ROCKER ARM SHAFT IS LOOSENED OR REMOVED. MAKE SURE ROCKER SHAFT STUDS ARE TIGHTENED TO 75-86 LB-FT (101-116 N.m).

Do not expand retaining clip more than 0.61 in. (15.50 mm) when installing retaining clip. To do so could result in damage to equipment.

Position concave (dished side) of intake valve button toward adjusting screw ball.

1. SLIDE RETAINING CLIP (1), OPEN END FIRST, ONTO ADJUSTING SCREW (2). SPREAD RETAINING CLIP (1) SLIGHTLY, IF NECESSARY, SO OPEN END CAN PASS OVER BALL HEAD OF ADJUSTING SCREW (2).

2. INSERT TIPS OF VALVE BUTTON EXPANDER (3) BETWEEN LEGS OF RETAINING CLIP (1). EXPAND CLIP ENOUGH TO INSERT GROOVE ON INTAKE VALVE BUTTON (4) ONTO LEG ARCS OF RETAINING CLIP (1).

3. THREADJUSTiNG SCREW (2) INTO CORRECT ROCKER ARM (5) AND INSTALL JAM NUT (6)

4. USING CUP PLUG INSTALLER (7), INSTALL NEW CUP PLUG (8) IN OIL PASSAGE (9) AT EACH ENDOF ROCKER ARM SHAFT (10).

If rocker arms are reused, install in previously determined order. Logo on rocker arm shaft must be on outboard (front and rear) when seated.

5. LUBRICATE ROCKER ARM BUSHING WITH CLEAN ENGINE LUBRICATING OIL. INSTALL THREE ROCKER ARM ASSEMBLY SETS (EXHAUST (11), INTAKE (12), AND INJECTOR (13)) ON ROCKER ARM SHAFT (10 WITH LOGO (14) STAMPED ON END OF SHAFT (10).

6. USING ROCKER STUD SOCKET (15), CHECK TIGHTNESS OF ROCKER ARM SHAFT STUDS (16) IN CAM CAPS (17) NO. 1 AND NO. 7. TIGHTEN STUDS TO 75-86 LB-FT (101-116 N.m).

7. USING ROCKER ARM LIFTER (18) ON ROCKER ARM ASSEMBLIES (19) FROM CAM ROLLER SIDE, PLACE ROCKER ARM SHAFT AND ROCKER ARM ASSEMBLIES (19) IN POSITION ON CAM CAPS (17).

8. INSTALL SIX SADDLE SPACERS (20) ON SIX RETAINING BOLTS (21).

9. INSTALL SIX RETAINING BOLTS (21) THRU ROCKER ARM SHAF (10) AND CAM CAP SADDLES.

10. INSTALL TWO SADDLE SPACERS (22) AND TWO NUTS (23) ON ROCKER ARM SHAFTSTUDS (16).

11. TIGHTEN SIX RETAINING BOLTS AND TWO NUTS TO 75-86 LB-FT (101-116 N.m) IN SEQUENCE SHOWN.

1. USING ACCESSORY DRIVE (1, BAR ENGINE (2) OVER. STOP ENGINE ROTATION WHEN ANY FUEL INJECTOR FOLLOWER JUST BEGINS ITS DOWNWARD STROKE. NOTE NUMBER OF THIS CYLINDER.

Timing circle can be started with any cylinder. Make sure timing circle is completed to set all valves and injectors.

2. REFER TO TIMING CIRCLE CHART AND LOCATE CYLINDER.

3. INSERT 0.008 IN. (0.203 mm) FEELER GAGE (3) BETWEEN TIP OF INTAKE VALVE STEM (4) AND INTAKE VALVE BUTON (5) AT END OF ROCKER ARM.

4. LOOSEN JAM NUT (6) AND TURN ADJUSTING SCREW (7) UNTIL FEELER GAGE (3) PRODUCES EVEN OR SMOOTH PULL BETWEEN INTAKE VALVE STEM (4) AND INTAKE VALVE BUTTON (5).

5. TIGHTEN JAM NUT (6) TO 30-35 LB-FT (41-47 N.m) AND REMOVE FEELER GAGE (3).

6. INSERT FEELER GAGE (3) AGAIN TO MAKE SURE ADJUSTMENT DID NOT CHANGE WHEN NUT (6) WAS TIGHTENED. READJUST AS NECESSARY.

7. EXHAUST VALVES ARE ADJUSTED SAME WAY AS INTAKE VALVES EXCEPT FOR USE OF 0.020 IN. (0.508 mm) FEELER GAGE.

8. COMPLETE ADJUSTMENT OF ALL VALVES (TWO INTAKE, TWO EXHAUST) FOR CYLINDER BEFORE PROCEEDING.

9. REFER TO TIMING CIRCLE CHART AND NOTE CYLINDER NUMBER FOR NEXT VALVE AND

Make sure injector timing height gauge is seated on machined surface with tip in pilot hole. Foreign m a t e r i a l i n p i l o t h o l e o r o n m a c h i n e d s u r f a c e m a y p r e v e n t accurate setting of injector height.

10. ADJUST HEIGHT OF FUEL INJECTOR (6) FOR CYLINDER INDICATED ON TIMING CIRCLE CHART BY PLACING SMALL END OF INJECTOR TIMING HEIGHT GAUGE (9) IN HOLE IN FUEL INJECTOR BODY (10) WITH FLAG (11) OF GAUGE TOWARD FUEL INJECTOR PLUNGER (12), AS SHOWN.

11. LOOSEN JAM NUT (6) AND TURN ADJUSTING SCREW (7) UNTIL FLAG (11) OF INJECTOR TIMING HEIGHT GAUGE (9) JUST CLEARS TOP OF FUEL INJECTOR PLUNGER (12). AN ACCURATE FEEL WILL BE DEVELOPED. ADJUST ALL INJECTORS TO SAME FEEL.

12. TIGHTEN JAM NUT (6) TO 30-35 LB-FT (41-47 N.m). CHECK ADJUSTMENT WITH INJECTOR TIMING HEIGHT GAUGE (9) AND, IF NECESSARY, READJUST.

13. REMOVE INJECTOR TIMING HEIGHT GAUGE (9).

14. REFER TO TIMING CIRCLE CHART AND FOLLOW ARROW TO NEXT CYLINDER IN ADJUSTMENT SEQUENCE.

COMPONENT                   CHECKING DIMENSIONS                   SETTING DIMENSION

FUEL INJECTOR        77.95 - 78.45 mm (3.068” - 3.088”)       78.2 mm (3.078”) (DDEC II)
                                                              78.8 mm (3.102”) (DDEC III)

INTAKE VALVE         0.152 - 0.254 mm (0.006” - 0.010”)       0.203 mm (0.008”)

EXHAUST VALVE        0.457 - 0.558 mm (0.018” - 0.022”)       0.508 mm (0.020”)

15. BAR ENGINE OVER IN DIRECTION OF NORMAL ROTATION UNTIL INJECTOR FOLLOWER OF NEXT CYLINDER IN ADJUSTMENT SEQUENCE BEGINS ITS DOWNWARD MOTION.

16. REPEAT VALVE ADJUSTMENT AND FUEL INJECTOR HEIGHT ADJUSTMENT PROCEDURES UNTIL ALL VALVES AND FUEL INJECTORS HAVE BEEN ADJUSTED.

17. CHART INDICATES ACCEPTABLE CHECKING TOLERANCES DETERMINED TO ENSURE ENGINE PERFORMANCE AND ALLOW FOR NORMAL VARIABILITY.