Hello,
It's been awhile since I've posted, but I often read and learn here and am thankful for all the thoughtful contributions.

I had read some archives around similar situations to what I'm facing, but thought a fresh thread wouldn't hurt too much.

I have an older Grizzly 1023 3hp cabinet table saw. I bought it used about a decade ago, and with minor tuning it has performed very well for all these years.

Last week I was doing a lot of work with a dado stack of blades installed when I started to hear a "rumbling" sound during operation (not just during breaking/stopping). I was able to finish the task at hand, and swapped back to a combo blade... which I then found was showing signs of vibrating and giving an unclean cut (where that has never been an issue previously).

With the saw unplugged, it is relatively difficult to rotate the blade by hand now. That was also never an issue before.

To date, I'll admit that my entire "maintenance regimen" for this tool has basically been to keep the top surface waxed. Never inspected or swapped belts or anything else.

My first thought is that the belts may need to be replaced, although I ran my fingers over them as my wife rotated the blade (saw unplugged) and didn't feel any obvious pits etc.

My second thought is that bearings may need to be replaced.

What do you think? Any tips on performing the steps of troubleshooting?

(I also sent a note to Grizzly to get their opinion)

Thanks!
Bob R.