pusher squealing belt

Suggest you recheck the tension on the new belts. Just because they are new doesn't mean that they won't squeal just like old ones if they are slippin.

When in doubt go to a Cummins repair place...they can re-tension the belt(s)

What engine-- most newer diesel engines have automatic tensioners.

Agree, you need to have bearings in accessories and tensioner checked along with the tensioner itself.

Here is a good short video by Gates Corp of a good/bad tensioner:

http://www.youtube.com/watch?v=uTLV5IU_IMM

Have you considered talking to the Monaco Service Center in Coburg, OR on I-5 and determining if they can help you? Engine mechanical is engine mechanical no matter what brand the coach.

If you have the cummins 400hp isl, I would look for a manifold leak. Sounds just like a squeal or whistle. I had mine checked at cummins NW in Coburg, OR. They replaced the manifold because it was warped too much to repair. It is a known issue. Look for black soot around the #3 cylinder. That's where my leak was. Will cost about $900 to replace. Good news is the replacement manifold is re-designed and with proper torquing, it should never be an issue again.

Bob

We have had excellent service at McKay Truck in Albany, OR just off the I 5. You can even over night there.

A very helpful mechanic did consult over the phone with pics and advice. Turns out it was the compressor for the air conditioner. Without that belt, the noise is gone. So, we'll drive home without air conditioning and get it fixed at the dealer.
While we are at the dealer, we'll have them check for a manifold leak...