TRACK S-CLA 1885334 - Caterpillar

Introduction
This technical information bulletin replaces a technical information bulletin that was written on 9October 2007. The title of the former technical information bulletin is "Broken Springs in the Fan Drive Group and the Belt Tightener Group in Specific Off-Highway trucks". Disregard the former technical information bulletin. Refer to the following technical information bulletin.Problem
Reports have been received from the field about the failure of the 125-5071 Spring . This causes the fan drive group or the belt tightener group to not work. The spring is part of the following groups.
125-5072 Belt Tightener Gp
183-8480 Belt Tightener Gp
240-9508 Fan Drive Gp
250-7573 Fan Drive Gp
265-8058 Fan Drive Gp
266-2367 Fan Drive Gp Solution
After a failure of the 125-5071 Spring on a 777F, replace the broken spring with the 7N-5959 Spring . The spring tension force of the 7N-5959 Spring is 25 percent lower than the spring tension force of the 125-5071 Spring . The 7N-5959 Spring was used in the 9N-6669 Belt Tightener Gp on the 773B Off-Highway Truck, the 777B Off-Highway Trucks, the 777C Off-Highway Trucks and the 777D Off-Highway Trucks.After a failure of the 125-5071 Spring on the other machines that are listed, replace the broken spring with a new 125-5071 Spring .
Illustration 1 g01425982
Illustration 2 g01425984
The 777F machines can contain either the 266-2367 Fan Drive Gp or the 240-9508 Fan Drive Gp . The 266-2367 Fan Drive Gp contains the 266-2362 Fan Bracket Assembly (1). The 240-9508 Fan Drive Gp contains the 274-1761 Bracket As (2). Both of the bracket assemblies attach to the engine block.
Illustration 3 g01425993
A potential cause may have been identified for part of the failures of the springs on the 777F. No clearance (4) between the bracket and the spring hook (3) may cause force to be applied to the spring. By using a pencil grinder, grind the bracket so that a 5 to 6 mm (0.2 to 0.24 inch) gap exists between the spring hook and the bracket. Make sure that the gap is present on the side of the bracket that is toward the spring. Install the spring hook with the opening upward.