Pump started screeching - repair or replace?

[aquarium]

The pump is starting to screech and it sounds to me like a worn bearing, but being new to pools I don't know what a worn impeller or other moving part would sound like. It's a bit random whether it does it each time it starts, but I know where this is heading.

Is there any way to isolate whether it's a pump or motor bearing? It's probably quicker to just replace the whole thing for now and rebuild the old one later for a stand-by.

Here's a couple of pictures:

http://i18.photobucket.com/albums/b113/tomwood2/pools/pump.jpg

http://i18.photobucket.com/albums/b113/tomwood2/pools/faceplate.jpg

Can someone make a recommendation for a good replacement? It's a 1 HP.

Those short sections of black pipe are threaded into the pump, can I just use a threaded/slip PVC fitting there on the new one? Also, this would be a whole lot easier if they'd installed it with unions. Is there a reason why I would *not* want to install some new unions?

EDIT: Also, is it okay to use a PVC slide repair coupling like the one shown below on the suction side of the pump? That would make matching up pipe lengths a lot easier.

http://i18.photobucket.com/albums/b113/tomwood2/pools/repaircoupling.jpg

[Poconos]

Could be either the motor bearings or the pump seal. My guess, and that is only what it is, is if it is the seal then running it dry and then with water will change the noise. Motor bearings would not be influenced by the presence of water. As for just replacing the whole pump and keeping it for a spare...I find an old pump very handy at times. When you redoo the plumbing definitely include unions. As for the PVC slip joint...never saw one. Mine squeals for a couple minutes when really cold, freezing or below, but then quiets down. Been doing that for years.
Al

[aquarium]

Mine squeals for a couple minutes when really cold, freezing or below, but then quiets down. Been doing that for years.
Al

Thanks,

This has just started with a little cold weather (for central Texas) so I think now I'll give it some time and see what happens.

[Poconos]

Yeah...give it time and as long as it shuts up don't sweat it. A friend has maybe the same pump that has been making a loud noise all season...started last season. My brain says it should have died long ago as no bearing or seal should make that much noise and last. However...other than the obnoxious noise it's still going strong. In late Fall and early Spring before I de-winterize I use an old Jacuzzi pump jury rigged to get the jump on circulation and also use it to pump stream water any time I need high volume flow for filling or whatever.
Al