My 2nd season old INTEX 1650gph sand filter motor became sooooooooo noisy we were turning it off when in the pool due to the noise. I mean dump truck with bricks rattling around in the back kind of noisy!
We came back from vacation and literally- I could hear it from the driveway.
I took a deep breath and tore into it.
Nothing around the impeller. Dug deeper. Got down to the motor only and it was without a doubt a bad bearing. Mind you- not much play in the motor shaft at all, but rock crushing noise when switched on.
I got the case separated and used a small 2 jaw puller to remove the bearings. (NOTE: a small "e" clip locates the bearing. remove before pulling. Another "e" clip locates the cooling fins which also have to be removed)
Bearing markings are 608 ZZ
The bearing size is 8mm(bore/I.D.) x 22mm (O.D) x 7mm(thick)
This is a common size for skateboard wheels.
I got this replacement bearing https://www.fastenal.com/web/products/details/0474510.
The cost for a pair including tax was $2.13.
I used a deep well socket with the same diameter as the inner race to gently drive the bearing back on, just making contact with the re-installed "e" clip.
Back together now and what's that you hear?..........NOTHING. Just water. It's as quiet as a church mouse.