Dear Metallo,

There are many issues affecting V-belt life, such as:
1. Pulley alignment & bushings
2. Pulley size
3. Pulley wear & smoothness
4. Belt quality & its rubber compound
5. Belt tension
6. Heat soak within engine compartment
7. Climate factor
8. Belt contamination
9. Alternator bearings
10. Crank pulley


The life of alt V-belt depends on a careful balancing act between the above factors. Sometimes you win sometimes you get in-between

Factor 1 - This self explanatory

Factor 2 - This regarding heat transfer. The big crank pulley gets the most heat from the engine and transfer it to the alt pulley. The alt pulley (being small) unable to quickly dissipate the heat. Thus the belt is sort of being "roasted" in between and this shorten its rubber life.

Factor 3 - Pulley does get worn over time. Check the contact surfaces to see any wear lines which slowly "eats" the belt.

Factor 4 - This self explanatory

Factor 5 - Low tension causes slipping thus affects grip and causes more wear. High tension weakens the belt's backbone (fabric backing) causing the belt to gradually losing tension. Lower tension causes slipping and this becomes a vicious cycle.

Factor 6 - Heat soak causes the rubber to gradually harden. Hardened belt rubber gradually slips and this goes back to Factor 5.

Factor 7 - Similar effect to Factor 6

Factor 8 - This self explanatory

Factor 9 - Worn alt bearings causes the belt to do "micro-jumps" (ie. slipping) in between engine revolutions. You'll see this as "belt flutter" or vibration along its length while running. Similar effect to Factor 5

Factor 10 - Spook has spoken ; )


I noticed that the alt belt is the one most affected. The power steering and AC ones could run almost indefinitely

My current practice is to replace the alt belt once every year or 1.5 year. I use BANDO a cheap Japanese brand easily obtained in Malaysia. I'm done using OE or Continental.

No more surprises!

Regards,
Amarin