The Stovebolt Site Forums The Shop Area Engine Shop Rattling noise after tune up. Not sure where it's coming from.

I "tuned up" the '51's 235 today with new plugs, points, condenser, rotor and cap, and when I started it up it had a whine to it, which wasn't there before. Nor has it ever had that sound. While I was under the hood, before I started it up, I shot some Belt-Ease on the fan belt. Maybe that could have caused it, but I don't know. Anyway, as I listened to the engine run, I noticed the belt was a little floppy at the vertical section on the left, so I turned off the engine and tightened up the belt (pulled out the generator a few hairs). It was snug, but still had some deflection. Well, I started it up again, and now it has some chattering, sort of like a bearing going bad. I grabbed a cut off broom handle and listened to the water pump, but it was just ticking like the engine, or at least it sounded quiet to me. Then I tried the generator and it was about the same, maybe a little louder ticking.

The water pump has been of the engine since I bought it 6 years ago. At that time, the seller, who was an elderly gentleman that was a shop owning mechanic from decades back, told me the '56 235 he replaced the 216 with, was professionally rebuilt and had about 2-3k on that rebuild when I bought it. It's just turned over 30k. I'm assuming that since it had 2020 miles on it when I bought it, and the new speedo is stamped a few years before I bought it, that the mileage is in line with the engine overhaul. So, it may need a pump, regardless.

I rebuilt the generator a few years ago with parts from Ken Warner at Classic Generator in Texas, but I didn't have a press to get the forward bearing out, so maybe I'm hearing a generator bearing? I don't even want to think about the crank! Anyway, it's not loud, but it wasn't making any noise before I tightened up that belt. Any body have any suggestions or similar stories that might give me a hint of what to look into first?

Take the belt off, then start it up and see if the noise goes away...

Mike B

While you have the belt off you can check for slop in the generator and water pump bearings, might not feel any play. Spin/turn the shafts and feel for roughness and noise.

Thanks guys, I'll try that. Don't know why I didn't think of that.

Generator has lube cups on either end but you only put a drop or two of oil in each. I was told that too much oil killed the armature and brushes.

Ok, here's a weird update- My 2004 Chevy 3500 Silverado Duramax, which performed flawlessly on a 2 hour trip to north of St. Louis yesterday, plus a run to our property we're getting ready to build on, 30 miles south of us, started acting up today, since my '51 is sickly. I got in it this morning, and it went into limp mode immediately. 250 miles yesterday, multiple starts and stops, and today it won't go over 10 or 15 mph, so i brought it back up the street and parked it. Being as how I'd promised one of my adult daughters that I would help her move by hauling all the junk to the dump, I needed a truck, but now I've got 2 problem trucks! Dang! I have a new water pump ordered from CP for the '51, but it won't be here for days (even though I'm in the same state- go figure). Anyway, I went out to take off the belt and have a listen to what might be making the noises, ready to wiggle and spin till I found the culprit. But first, I thought I'd fire it up to make sure all was ready for when I got the belt off. But when I started her up, the noise is gone. No whining, no rattling, and it even sounded better after the tune up. Sometimes I just don't know what the heck is going on in my world. So now the '51 is running great, but the '04 is limping. Oh well. at least one of them are drivable for the time being. Thanks for the help and advice, everybody. I have no idea what caused or cured the problem, but you helped out. Thanks for reminding me to lube the generator, Greg. I forgot about that and haven't done it since I rebuilt it.

Keep the two trucks separated and hurry up and sell the 2004 before the Gremlin hops back into the '51!
I am usually right about matters like this...
Seriously, that's the best I got for this mystery. You could take a chance, keep the 2004, and just drive the '51 and see if the noise comes back.
Carl

Concerning Greg’s post about oiling the bearing cups; after I had my generator rebuilt, I asked the shop owner about how often I should oil them, and he said never, the new bearings are sealed and do not require it. My oil cups are still there, not sure where the oil would go if I put any in.

Lee.

Thanks, guys. Hmm. I don't see how it could hurt the shaft any if a few drops of oil were added occasionally, but I understand what you're saying, and thanks. But as I said above, I didn't have the tools (or time to find someone who did, since this is my daily driver) to get the old main front bearing driven out, so it's still whatever was in there before I rebuilt the rest of it. One of these days when I tear down the old bomb for a ground up restoration, I'll put the new bearing in it and check the brushes in it. OR- if it goes out before then. I'm not lazy, but I've always been a firm believer in "if it works, don't fix it". For example, the $185 water pump, gasket, pulley and thermostat I just bought 'just in case' the pump was bad, will sit in their box until the day that it actually fails. But when I do get in there and tear apart that generator, I will remember this. Thanks again, everybody! The truck is still whizzing (quietly- well, as quietly as an old '56 235 can be) down the roads of southeast Missouri as of now.