EDGE-CUTTING 1955124 - Caterpillar

3508 (23Z, 70Z, 1ZF),
3508 EUI (5XM, 3LS),
3508B (6PN, 4GM, 2HW),
3512 (24Z, 67Z, 3YF),
3512 EUI (6PM, 3MS),
3512B (8RM, 6WN, 4AW),
3516 (25Z, 73Z, 4XF, 5SJ),
3516 EUI (7KM, 3NS) 3516B (7RN, 6HN, 1NW) Generator Set;
3508 (96Y, 69Z),
3508 EUI (3PS),
3508B (7SM, 2BM, 1TW),
3512 (50Y, 66Z),
3512 EUI (3RS),
3512B (4TN, 7HM, 2GW),
3516 (29Z, 72Z, 4MJ, 5MJ),
3516 EUI (3SS),
3516B (8KN, 8CN, 3CW) Marine;
3508B (3DM, 3DW),
3508 EUI (3TS),
3512B (8EM, 1PW),
3512 EUI (3WS),
3516B (9AN, 2FW),
3516 EUI (3XS) Marine Auxiliary;
3508 (95Y, 68Z) 3512 (49Y, 65Z, 1LM),
3516 (27Z, 71Z) Industrial;
3508 (6TJ),
3508B (5PS),
3512 (2WK),
3512B (3ZW),
3516 (9KF) Locomotive;
3508 (97Y),
3512 (51Y),
3516 (28Z) Vehicular Engines;
G3508 (4WD, 2JF, 9TG, 9AW),
G3512 (4KC, 5JD, 7NJ, 6JW),
G3516 (3RC, 8LD, 4EK, 5PN, 8PW) EnginesSUPPLEMENT: OCTOBER 1998Engine News SEBD9264, Article 10, Page 8, September 1998; "Recommended Lubrication And Torque Procedure For Connecting Rod Bolts".The subtitle (lisft of applicable commercial engines) is incomplete. Add the following G3500 Engines to the list.G3508 (4WD, 2JF, 9TG, 9AW),G3512 (4KC, 5JD, 7NJ, 6JW)G3516 (3RC, 8LD, 4EK, 5PN, 8PW) Engines
--------------- END SUPPLEMENT ---------------The quality of the joint between connecting rod and cap depends on the proper bolt stretch. Bolt stretch is determined mostly by the torque applied to the bolts but is also affected by the type of thread lubricant used. The only acceptable lubricant for connecting rod bolts is 6V-4876 Molykote lubricant. The use of a thread lubricant on connecting rod bolts other than Molykote will lead to improper bolt stretch and possible bolt or thread damage.
The tightening procedure for connecting rod bolts is as follows:
Bolt Tightening Sequence(1) Rod cap.(2) Rod bolts.(3) Location of pin in cap.1. Lubricate bolt threads, shank, and bolt head seat with 6V-4876 Molykote lubricant before assembly. Do not use any other lubricant on the bolt threads.2. Tighten bolts A and B to 90 5 N m (66 4 lb ft).3. Tighten bolts C and D to 90 5 N m (66 4 lb ft).4. Retighten bolts A and B to 90 5 N m (66 4 lb ft).5. Retighten bolts C and D to 90 5 N m (66 4 lb ft).6. Tighten each bolt in sequence an additional 90 5 degrees.Connecting rod bolts can be reused at the first and third overhauls. The rod bolts should be replaced at the second and fourth overhauls.
One way to damage a bolt at overhaul is to clean it improperly. If a bolt needs more than wiping off, clean it in a mild petroleum based solvent. Make sure the solvent has not been contaminated with water. If contaminated, the solvent will pit the bolt. Also, be sure and never clean a bolt with a chlorinated solvent. The chlorine will attack the bolt surface and leave pits. A pitted bolt will fail at low hours.
See the Guideline For Reusable Parts, SEBF8301, Inspection And Reuse Of Critical Fasteners For All Engines, for more information on reusing bolts.