Caterpillar 3412C — Alternator and Fan Belts - Inspect/Adjust/Replace
Adjustments · Alternator and fan drive belts
For the Caterpillar 3412C, from the Caterpillar owner's manual.
Applies to: Caterpillar 3412C, Caterpillar 3412C engine
Before you start
- Replace multiple drive belts in matched sets
Parts for this job
- 118-2018 Belt — Caterpillar 3412C eBay $74.43 FridayParts $21.56
Part numbers from the service-parts lists for Caterpillar 3412C, Caterpillar 3412C engine. Verify against your serial number before ordering; some links are affiliate links.
Procedure
- Check belt tension between the first 20 to 40 hours.
- Apply 110 N (25 lb) of force midway between pulleys.
- Belt should deflect 13 to 19 mm (0.50 to 0.75 inch).
- Loosen mounting bolts and the adjusting bolt.
- Move the alternator to increase or decrease belt tension.
- Tighten adjusting bolt; tighten mounting bolts.
- Check tension again after 20 hours if new belts installed.
Specs & values
- Belt deflection 13 to 19 mm (0.50 to 0.75 inch) with 110 N (25 lb) force
Full service-parts list: Caterpillar 3412C →, Caterpillar 3412C 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.