bornpeace

If the belt is backward they will be no broken-in and reseated, what you will be doing is damaging the belt. Check this tutorial for your car http://www.lexls.com/tutorials/maint...drivebelt.html
The drive belt should last around 60,000 miles or 72 months, so if that is the original belt i will advice you to get a new one(is around $40 for OEM) again check you pulleys. Follow the tutorial, if not get a mechanic to do it for you.

somnoboy

Thanks dean and bornpeace. I'll have a look at the tutorial link, and do some more noodling.

somnoboy

Took it to a local ex-Lexus mechanic. Took off old belt (appears to be in good condition; no cracks, etc... appears to be OEM, not sure when it was replaced). Checked free spinning pulleys; everything good. Put on new serpentine belt, turned A/C on; still making sort of labored, gearing sound. Mechanic determined that my a/c compressor was starting to go bad. It wasn't the serpentine belt, although there was a slight squealing sound that the mechanic thought was the belt slipping a little. (The squealing sound did go away with the new belt, but I didn't think the difference was that great, so decided not to replace with the new belt.) We put the old belt back on.

So, while the A/C still works fine for now, I guess it is on its way out. I didn't replace the compressor now, especially since it's the start of winter, and won't have a need for it for a good 6 months or so. But I will replace it when it dies.

Thanks again to everyone who posted the suggestions above. Your tips and posts were a great help to me. I am grateful.

JimsGX

Your A/C comes on to keep your windows from fogging up even in the winter. Hopefully it won't be an issue for you over the winter.

somnoboy

Thanks for the tip. I typically don't use the a/c at all during the winter.

deanshark

What JimsGX is referring to is that your A/C compressor turns on when you turn on the front defroster to help clear the fog off the inside of the windsheild. It's alot better than the unconditioned air. But, maybe it will last b/c you don't use it too much.

somnoboy

Thanks dean. I think it's good for now. Thanks for all your help.