Usage:
NOTE: The information supplied in this service letter may not be valid after the termination date of this program. Do not perform the work outlined in this Service Letter after the termination date without first contacting your Caterpillar product analyst.
NOTE: This Program must be administered as soon as possible. When reporting the repair, use "PI3575" as the Part Number, "7751" as the Group Number, "56" as the Warranty Claim Description Code and "T" as the SIMS Description Code. Exception: If the repair is done after failure, use "PI3575" as the Part Number, "7751" as the Group Number, "96" as the Warranty Claim Description Code, and "Z" as the SIMS Description Code.
NOTE: This Revised Service Letter replaces the January 14, 1992 Service Letter. Changes have been made to the Rework Procedure.
Completion Date
June 30, 1992Termination Date
January 31, 1993Problem
The four 6H3958 Socket Head Bolts in the timing advance mechanism may loosen which can cause the 0T0065 Bolts to loosen or break on certain 3406B PEEC Truck Engines. Loose or broken bolts can result in damage to the hydraulic timing advance, cause hard starting and/or internal engine damage.
Affected Product
Model & Identification Number
3406B (2EK180-575, 2EK577-600, 2EK602-677, 2EK679-871, 2EK873-1108, 2EK1110-1123, 2EK1127-1190, 2EK1192-1278; 4CK169-186, 4CK190-217)
Parts Needed
Dealers will need to order parts for this Program.
Action Required
See the attached procedure.
Owner Notification
U.S. and Canadian owners will receive the attached Owner Notification.
Service Claim Allowances
NOTE: A complete engine wash or road test after repair are not necessary for completion of this Program.
NOTE: U.S. and Canadian Dealers Only - This Program does not qualify for a Type 2 SIMS Report.
Parts Disposition
Handle the parts in accordance with your Warranty Bulletin on warranty parts handling.
NOTE: MAKE EVERY EFFORT TO COMPLETE THIS PROGRAM AS SOON AS POSSIBLE.
- (1-Owner Notification)
- (2-Rework Procedure)
Attach.
Copy Of Owner Notification For U.S. And Canadian Owners
Rework Procedure
The four 6H3958 Socket Head Bolts can loosen which allows the 4P2921 Guide Ring to work against the eight 0T0065 Timing Advance-Drive Bolts. This can cause one or more of the 0T0065 Bolts to loosen and back out or break. Loose or broken 0T0065 Bolts can damage the hydraulic timing advance and its related parts. If damaged parts enter the front gear train or fuel injection pump, additional damage can result. When the 6H3958 Bolts become loose, it is also possible that the timing advance can not retard the fuel injection timing due to an oil leak path by the 4P2921 Guide Ring. Advanced timing can cause hard starting and other internal engine damage.
1. Perform the first seven steps of the procedure, "Checking Engine Timing By the Timing Pin Method", in the Testing and Adjusting section of the Service Manual.
If the timing bolt goes in the flywheel, go to Step 2 of this Rework Procedure.
If the timing bolt does not go in the flywheel, perform Step 8a through e of the above procedure to position the engine on TDC. Then go to Step 2 of this Rework Procedure.
2. Leave the 6V4186 Timing Pin in the slot in the fuel injection pump camshaft and the timing bolt in the flywheel.
3. If not already done in Step 1 above, remove timing sensor, timing solenoid and timing advance housing following the procedure, "Remove Timing Advance Unit", in the Disassembly and Assembly section of the Service Manual.
4. Loosen the eight 0T0065 Drive Bolts. Note the tightness of the bolts as they are loosened.
5. Remove the eight 0T0065 Bolts. Inspect the bolts for polishing and wear on the shank and threads. Slight polishing on one or two bolts is not unusual. Polishing or wear on all the bolts is an indication that the 6H3958 Socket Head Bolts are loose.
6. Remove the complete timing advance unit.
7. Note the tightness of the four 6H3958 Socket Head Bolts.
If either the 0T0065 or 6H3958 Bolts were loose, go to Step 8.
If the 0T0065 Bolts were tight and show only slight polishing and the 6H3958 Bolts were tight, go to Step 9.
8. Remove the four 6H3958 Bolts and inspect the 4P2921 Guide Ring, 4P2923 Drive Ring and 4P2922 Plate for wear or damage. Replace parts as necessary. Use twoNC guide pins to align the guide ring, drive ring and plate. Go to Step 10.
9. Remove the four 6H3958 Bolts.
10. Replace the 6H3958 Bolts with the new 6J2819 Bolts. These bolts are 6.35 mm (.25 in.) longer for additional thread engagement in the 4P2922 Plate.
11. Tighten the 6J2819 Bolts to a MAXIMUM torque of 16.2 N·m (12 lb.ft.). This is a new torque value.
12. Before installing the timing advance, push in on the end of the 4P2642 Carrier Assembly to make sure that it is fully retracted (retard position). Approximately 18 kg (40 lbs.) of force may be required to move the carrier assembly.
13. Use twoNC guide pins to install the timing advance on the end of the fuel injection pump camshaft. Do not reuse the original 0T0065 Bolts. Install eight new 0T0065 Bolts finger tight.
14. Tighten all eight 0T0065 Bolts to a torque of 10 N·m (7 lb.ft.).
15. Remove the 6V4186 Timing Pin.
16. Tighten the eight 0T0065 Bolts to a torque of 55± 7 N·m (41 ± 5 lb.ft.). This is the original high torque value for the timing advance drive bolts.
17. Tighten the eight bolts to the above torque value again to make sure that all eight bolts are uniformly tight.
18. Remove the timing bolt from the flywheel.
19. Check the timing by following the procedure, "Checking Engine Timing By Timing Pin Method", in the Service Manual.
20. Install the plugs in the fuel injection pump housing and the flywheel housing. Install the timing bolt in its storage location.
21. Install the timing advance housing.
22. Install the timing sensor and calibrate the sensor following the procedure in the Service Manual. Make sure that the 1U5425 Timing Gauge Assembly is removed from the timing advance after calibrating the timing sensor.
23. Install the timing solenoid making sure that the lever of the solenoid is engaged in the timing advance sleeve.
24. Install a new security seal and stamp the letter "T" on the side of the block next to the Serial Number Plate.
Illustration 1