[Archived]

My suggestion would be to remove the existing belt and take it with you to the store. Far too many belts bought as spares have been found to be the wrong size.

[Corey]

My local NAPA leaves a lot to be desired when it comes to Prevost stuff. None of their computers and/or books list Prevost. So I have to do my homework to get anything done with them.

My Autozone isn’t any better, but today I got lucky. I measured the big 12 rib serpentine belt for the big 24v alternator w/a string, on the engine, 72″. Then with the counter persons knowledge it was determined(12 ribs-72″) my 24v alternator Dayco belt # is 5120720. My fan belt is 5100510(10 ribs-51″) I had determined that on the forum and w/measurements.

I could read the part#s on the 3 belt setups that go to the 90 degree gearbox(Dayco#AX74), and the OTR compressor(Dayco#BX97).

For the little 12v alternator I’ll take the belt off and have them match it up in store tomorrow.

[Archived]

I had the old style tensioner but after a couple of years I ran into recurring belt failures (5 in a row). Turns out one of the idler bearings was marginal. It worked fine when cold which is usually when I inspected it. It seized up on occasion when hot which would quickly shred the belt. If your belt starts getting ribs cut off, install new bearings which is much cheaper than replacing the old tensioner assembly. I have the bearing on my desk, it still turns fine but the balls are rattling when you shake it.

Another disadvantage of the old style tensioner is that it is easy to overtension the belt which will stress the alternator bearings.

I installed the new automatic tensioner upgrade kit which solved all the belt issues I had last year.

Gerald

[June]

Gerald mentions a little discussed point.

As a periodic check, relax your belts and spin the idler pulleys. If you hear a “growling” noise or feel some resistance to turning replace the pulley or the bearing. We have had numerous reports of failures and it is not a big or expensive fix, but if there is a failure on the road it can get expensive.

[Archived]

Called Liberty and asked what belt p/n was used for the little 12v alternator driven by the 90 degree gearbox. They told me Dayco BX31 $9.99 @ Autozone. I looked it up online and it matches the dimensions of what’s on me coach. AWESOME 🙂