A belt inspection at least twice a year is a good idea, regardless of miles. Age, coolant leak, oil leak, racing(heat), etc., are all factors in the lifespan of the belt. If it gets wet with oil or coolant; change it. If it has age, or stress cracks; change it. I think 60,000 miles is the mark that I remember for changing serpentine belts, given no other issues of course.

 

Do take a close look at the 60mm idler that is rusty. THIS IS the Achilles heal of the ASP crank pulley kits. This pulley has very little margin on its RPM limit in this application AND IS ALWAYS the first to go.

A better replacement is this metco motorports pulley this not only dual bearing but it ALSO has higher speed rated bearings.


Billet Idler Pulley 63mm, 2003-2004 Mustang Cobra: Metco Motorsports (the 8rib one is correct for this application)

Cheers,
Chris

 

I just changed out my 140,000 mi SRT belt, it was original...They "love you long time"

 

LOL...... You gambled and won.