Caterpillar 3126B / 3126B Industrial Engine — Belt - Inspect (Adjustment)
Adjustments · Alternator belt / water pump belt
For the Caterpillar 3126B / 3126B Industrial Engine, from the Caterpillar owner's manual.
Applies to: Caterpillar 3126B, Caterpillar 3126B Industrial Engine engine
Before you start
- Replace belts that are worn or damaged. Replace multiple drive belts in matched sets.
Procedure
- Check belt tension initially between the first 20 to 40 hours of engine operation, with the engine stopped.
- 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).
- For alternator belt: slightly loosen mounting bolts and adjusting bolt, move pulley to adjust tension, then tighten.
- For water pump belt: slightly loosen mounting bolt and adjusting bolt, adjust tension with a square drive in square hole, then tighten.
- Install the belt guard.
- If new belts are installed, check tension again after 30 minutes of operation at rated rpm.
Specs & values
- Deflection 9 mm (0.35 inch) to 15 mm (0.59 inch) at 110 N (25 lb ft) force
Full service-parts list: Caterpillar 3126B →, Caterpillar 3126B Industrial Engine engine →
Source: Caterpillar owner's manual. Steps and values are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.