Replacing my serpentine belt- advice?

I just replaced my 2007 belt yesterday. Was second replacement. First was by prior owner at 128k seven years ago and now this one a bit over 190k. So current interval is about 60k+/- miles.
The belt looked fine from outside, in fact even the dealer didn’t see anything of concern in oil and other changes over the years, but once it was off the car, it was clear that it was heavily cracked. Was scary to look at especially in summer heat.
As best I can tell Toyota says 60-100k change interval. From now on I’m planning on changing it at 50k. May be overkill and it could also have been the seven years that were important but a small expense to avert a major problem on the road.

 

For what it's worth, the rubric in the Gen 1 repair manual (on page CO-4) was "HINT: Cracks on the rib side of a belt are considered acceptable. If the belt has chunks missing from the ribs, it should be replaced."

There's an accompanying picture that shows a belt with a chunk gone from the rib side, as well as a belt with any cracking visible on the flat side.

 

Really, I just perform a good visual inspection every time I perform routine servicing during oil and filter change. Take a strong flashlight and look at the inside of the belt- twist it if needed and get a feel for the tension. Look all around in and under the engine compartment for fluid leaks, damaged hoses or wires, etc.
Don't care what the manual says- if I see cracks in a rubber part (belt, hose, whatever) then it's on the way out and should be replaced.

Posted via the PriusChat mobile app.

 

I just did my 2009 with 320K miles on it for the first time. The old belt still looked fine. The outside still looked new. No missing pieces. The ribs had a few cracks but honestly it looks about the same as it did when it had 80K miles on it which is the first time I inspected it.