DIESEL ENGINE BASIC 5A9531 - Caterpillar

Bolt Tightening Sequence7/8Current Cylinder Block With inch Size Main Cap Bolts
1. Lubricate bolt threads and under head radius with engine oil before assembly. Do not use any other lubricant on the bolt threads.2. Tighten bolts 1 through 4 in number sequence to a torque of 190 14 N m (140 10 lb ft).3. Turn bolts 1 through 4 in number sequence another 180 5 degrees. 3/4Early Cylinder Block With inch Size Main Cap Bolts
1. Lubricate bolt threads and under head radius with engine oil before assembly. Do not use any other lubricant on the bolt threads.2. Tighten bolts 1 through 4 in number sequence to a torque of 136 14 N m (100 10 lb ft). 3. Turn bolts 1 through 4 in number sequence another 210 5 degrees. Main bearing cap bolts are generally reusable through 60,000 hours. Do not reuse a main bearing cap bolt beyond 60,000 hours.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.