Community Forums

kenwyatt · 10-30-2022, 08:11 PM

Very interesting, just checked and the drawings show a O-Ring

though it was a snap ring. Seems like a strange place for a O-Ring. Have you removed a a endbell from this particular generator set before?

RamiDav · 10-31-2022, 09:17 AM

Ken there are things you could try such as machining you worn part and installing a slightly larger bearing, machining and sleeve, or Loctite.

Loctite would be the easiest but may not hold up.

I would lean towards machining.

153stars · 10-31-2022, 12:00 PM

Makes me wonder the condition of the other bearing if loosing these.
Locktite makes a specific fluid for retaining a race or bearing on a shaft you could press out new bearing and use Locktite.
Machining a sleeve tighter than tolerance might work. So sleeve shrinked with cold end bell heated then pressed in. Often final bore is done after. The work is not cheap probably close to a new part or more.

RamiDav · 10-31-2022, 12:22 PM

Here's an interesting forum with talk about Loctite & spun bearings

https://forums.yesterdaystractors.co....php?t=1279102

kenwyatt · 10-31-2022, 12:54 PM

The other end of the rotor is solid mount to a hub that’s mounted to a plate and that’s mounted to the flywheel. All mounting is done with bolts. Not saying something isn’t loose.will know when I get it apart. Could also be a out of balance rotor and will try to have the balance checked on that as well.

bigb56 · 10-31-2022, 01:06 PM

Quote:

Originally Posted by 153stars

Makes me wonder the condition of the other bearing if loosing these.
Locktite makes a specific fluid for retaining a race or bearing on a shaft you could press out new bearing and use Locktite.
Machining a sleeve tighter than tolerance might work. So sleeve shrinked with cold end bell heated then pressed in. Often final bore is done after. The work is not cheap probably close to a new part or more.

Yep, I just used it on a Baldor 8" grinder. I put the Locktite on then staked the edge a bit, waited 24 hours and so far it's held over 3 years. Used it again on my Milwaukee belt sander, so far holding the bearing fine. Couldn't stake that one, plastic case.

randomledder · 10-31-2022, 07:33 PM

The O’Ring allows the bearing to float in the housing preventing any loading of crankshaft endplay one way or the other during temperature shifts. Or at least that’s my understanding. I wouldn’t want the bearing lock.tighted into place. Just my two cents though.

153stars · 10-31-2022, 10:48 PM

I have belt driven alternator on my Generac. Is Onan directly hard coupled to crankshaft of motor.

Quote:

Originally Posted by randomledder

The O’Ring allows the bearing to float in the housing preventing any loading of crankshaft endplay one way or the other during temperature shifts. Or at least that’s my understanding. I wouldn’t want the bearing lock.tighted into place. Just my two cents though.

kenwyatt · 11-01-2022, 06:19 AM

It does appear to “Float “ somewhat. The service manual has the procedure to change the bearing and it says to use locktite on the shaft to bearing surface but says to apply grease to the O-Ring to allow it to “slip” into the housing. Next step is to pull the endbell and see the inside better. Will also try and contact Onan. Would love to have a drawing with dimensions to comparison. You may be correct and the O-Ring is gone for whatever the reason. Thanks for the insight

kenwyatt · 11-01-2022, 01:01 PM

Yes it’s hard coupled to the engine flywheel

153stars · 11-01-2022, 08:35 PM

I suppose O-ring pre-compression may help to prevent spinning outer race in the housing if extra float is in the clearances.It may be important to get OEM for the proper durometer O-ring. 70 durometer is most common but this detail seems it may be highly critical now.
I hope you get a good long term outcome for this issue.

kenwyatt · 11-02-2022, 07:08 AM

Me too, have a trip coming up the last part of December and like having the generator in case I want to boondock overnight. I ordered 2 o-rings that are OEM. Will know more when I get it apart.

RamiDav · 11-02-2022, 08:44 AM

I absolutely don't claim to be an expert, but I can't wrap my mind around the gen being truly hard connected to the engine. It seems to me it would have to have some sort of flex coupling, or the alignment would need to be so near perfect or else it would tear itself apart, but then maybe that's what is happening. Are some of you thinking the bearing is supposed to not be a really tight fit into the bell end so that it can move? That seems like a recipe for failure too. I too would like to know what purpose the Oring serves, it does appear it may be an end play cushion, but that seems odd.

Monaco_hwy · 11-02-2022, 09:07 AM

These types of engine/generator designs are hard coupled. There are 3 bearings; two in the engine and one on the generator end. The three bearings must be in perfect alignment. There must not be any play in any of the bearings, or there will be vibration and rapid wear. If the bearing is loose in the generator housing, then it is bad and must be fixed, or it will get worse and have a catastrophic failure.

You can test the alignment using a dial indicator on the generator shaft when the generator rotor is unsupported. There should be no more than .001" or so motion as you rotate the engine. If it is much worse than that, you have a bent shaft or a loose coupling.

If the bearing has spun in the generator housing, then it may have wallowed out the hole. The housing must be replaced or some fancy machining work must be done so that the bearing is held firmly.