Generator squealing

[pvienneau]

When running the 216 engine I was hearing a hollow metal sound from the front of the engine compartment. Took belt off and ran engine. No noise. SPun the generator by hand and could hear the sound. I squirted some silicone in the generator and put the belt back on. Quieted the noise for a little while but returned. Should I be replacing or rebuilding the generator? Is it getting old?

[nvrdone]

could be the brushes are worn out. I'd pull it apart for a look see

[mr48chev]

I haven't had one apart in close to 50 years but Napa says it takes two 6203 RSJ bearings http://www.napaonline.com/Catalog/Re...30433/Ne-25000 You can get them for a lot less on Amazon or other sources though Amazon.com: 6203rs bearingIt may have a bronze bushing in the back end though http://www.napaonline.com/Catalog/Ca...242_0060683340

New brushes don't cost that much if it needs brushes.

Or you could have your unit rebuilt at a local automotive starter and generator shop for around the same cost as buying a rebuilt.

Offhand I don't have the instructions on how to rebuild one handy but they should be in the service manuals for these trucks. I just haven't dug the service manual I have out of the pile.

[magicoolbus]

A common problem is to tighten the belt to much. The proper tension is achieved when you can move the generator pulley by hand. Push on the genie cooling fan and you should be able to turn it with out too much force.

[pvienneau]

Thanks for the advice. It was the generator fan rubbing against the body of the generator. I pulled it and put in a rebuilt I had on the shelf. Silence. Weird how all of a sudden the fan is jammed up against the body. I'll do a rebuild and see if I can figure out what happened.

[OrrieG]

I'd guess bearing wear allowed some end play...

[starterman99]

A lot of these old delco generators use a bushing on the commutator end. If the belt is overtightened it will ruin the bushing very quickly especialy if they have not been lubricated in a while.

[mr48chev]

Good point Starterman99. anything that is run by a V belt suffers when the belt is overtightened. I've had a vehicle owner tell me more than once that I hadn't tightened the belt tight enough after replacing a bad alternator or waterpump on their rig because I had set it to the "correct tension" rather than guitar string tight as they had it. It kept them coming back for more waterpumps and alternators though as they never seemed to learn the lesson.

[pvienneau]

Makes sense. I have the belt correct on the new generator as outlined in the manual. 3/4 inch on a straight edge.

[pvienneau]

To close this one out, I found that the pulley on the generator was completely cracked and split off from the fan. I welded it back up and plan to convert to a 12 volt.