REGULATOR 3608828 - Caterpillar

Off-Highway Truck/Tractor:
69D (S/N: 9SS1-UP; 9XS1-UP)
769C (S/N: 01X7152-UP; 48W41609-UP)
769D (S/N: 5SS200-UP; 5TR1055-UP; 99C5534-UP and 5535-UP)
Quarry Truck:
771C (S/N: 3BJ282-UP)
771D (S/N: 6JR310-UP; 6YS134-UP)
Service Magazine SEPD0531, 3 JULY 2000, "A New Flywheel Assembly is Available for Off-Highway Trucks". Replace this article and the supplement with the article that follows.Description of Change: A new flywheel assembly is now available for Off-Highway Trucks. The flywheel assembly for the 2W-6533 Flywheel Group has changed from 1W-8170 Flywheel Assembly to 8N-8666 Flywheel Assembly. The 8N-8666 Flywheel Asssembly is made from a stronger material. The stronger material reduces the chance of cracking in the bolted joint area. The 1W-8170 Flywheel Asssembly may crack during high hour life of the truck. This will result in the loss of bolt clamping load which directly leads to the breaking of the bolts.Adaptable To: The 8N-8666 Flywheel Assembly is adaptable to the following Off-Highway Trucks: 69C-101 and Up, 69D-101 and Up, 69D (S/N: 9XS), 769C (S/N: 01X), 769D (S/N: 5SS) and 769D (S/N: 5TR). The 8N-8666 Flywheel Assembly is adaptable to the following Quarry Trucks: 771C (S/N: 3BJ), 771D (S/N: 6JR) and 771D (S/N: 6YS).The rubber damper should be replaced after a flywheel bolt breaks. These machines have a drive line that is tuned to only work as a system. The crankshaft damper must be in good condition. Refer to the following Service Magazine articles for further information about dampers.
Service Magazine, SEPD0268, 21 AUGUST 1995, "Recommendations for Inspection and Replacement of Rubber and Viscous Crankshaft Dampers"
Service Magazine, SEBD1471, 2 JULY 1984, "Procedure Changed to Test Engines Out of Chassis"
Service Magazine, SEBD1470, 25 JUNE 1984, "New Vibration Damper Assembly Has Better Heat Resistance"
Service Magazine, SEPD0203, 25 APRIL 1994, "Crankshaft Damper Group Change Improves Control of Torsional Vibrations"When you install the 8N-8666 Flywheel Assembly, be sure to use 1N-3825 Bolts and 3G-8856 Washers.