STUD-BALL 8J5392 - Caterpillar

Caterpillar: Confidential Yellow
SAFETY REPLACE, INSPECT, AND/0R RETIGHTEN CRANKSHAFT COUNTERWEIGHT BOLTS 3508, 3512, 3516 ENGINES - MAILED US AND CAN ADA, CACO, COFA, BRAZIL, CFEL, COSA
  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.
REPLACE, INSPECT, AND/OR RETIGHTEN CRANKSHAFT COUNTERWEIGHT BOLTs, 3508, 3512, 3516 Engines, 1202 PI1007 U-55 A-49 AU-43 B-21 C-51 E-45 O-37 SAFETY Cross out your copy of the March 16, 1983 Service Letter PI3005, and add a note referring to this new Safety Service Letter. PI3005 is canceled. Problem There are now two potential problems with the crankshaft counterweight bolts on the above engines. First, as announced in the March 16, 1983 Service Letter, engines may have loose or improperly tightened bolts. Now, more recently we have discovered some of these bolts used in later engines and for parts service are too brittle and the heads can break off. Loose or broken bolts can cause the counterweight to interfere with the connecting rod. This interference usually breaks the remaining counterweight bolts. The loose counterweight will damage the engine and could be thrown through the side of the block. Bolts with good material are now used in production and are in the Parts Department. Part number did not change, but the good bolts can be easily identified from the potentially defective bolts by the arrangement of the letters on the heads. See Illustration. (SEE ILLUSTRATION) For a short time, bolts with known good material were used in production, but with markings the same as the bolts with potentially defective material. These bolts have a dot of red dye on the bolt head. Some engines have been reworked at the factory and are identified by the stamp "N-9" on the block near the serial number plate. A special lubricant instead of engine oil is still used on the bolts to prevent any damage to the mating parts when the bolts are tightened, and the tighter torque-turn method is used. Affected Engines, Parts Needed, Labor Allowances There are four areas of concern to be covered by this Safety PIP as a result of the two problems with the counterweight bolts. There are three groups of engines, A, B, and C, which need different work and quantities of parts. Parts stock inspection is designated as area (D). A) Later engines shipped with possibly defective bolts. B) Earlier engines shipped with some possibly loose or improperly tightened bolts of good material, and not yet inspected or reworked with new bolts per March 16, 1983 Service Letter. C) Engines shipped with some possibly loose or improperly tightened bolts of good material (Group B), but already reworked with new, parts service bolts. These parts service bolts may have the defective metal. D) Possibly defective bolts in dealers' parts stocks. The