GASKET 2P8763 - Caterpillar

Inspection
Belt tension should be checked initially between the first 20 to 40 hours of engine operation.To maximize the engine performance, inspect the belts for wear and for cracking. Replace belts that are worn or damaged.For applications that require multiple drive belts, replace the belts in matched sets. Replacing only one belt of a matched set will cause the new belt to carry more load because the older belt is stretched. The additional load on the new belt could cause the new belt to break.If the belts are too loose, vibration causes unnecessary wear on the belts and pulleys. Loose belts may slip enough to cause overheating.If the belts are too tight, unnecessary stresses are placed on the pulley bearings and on the belts. This may shorten the service life of the components.Inspect the condition and adjustment of the alternator belts and accessory drive belts (if equipped).To check the belt tension, apply 110 N (25 lb ft) of force midway between the pulleys. A correctly adjusted belt will deflect 9 mm (0.35 inch) to 15 mm (0.59 inch).Alternator Belt
Illustration 1 g03749066
Typical alternator mounting
(1) Adjusting nuts
(2) Mounting bolts
Slightly loosen mounting bolts (2) and adjusting bolt (1).
Move the pulley in order to adjust the belt tension.
Tighten adjusting bolt (1) and mounting bolts (2). For the proper torque, refer to the Specifications Manual, SENR3130, "Torque Specifications".
Install the belt guard. If new belts are installed, check the belt tension again after 30 minutes of engine operation at the rated rpm.