Onan Locked Up

ah yes - i forgot that they were air cooled

bshpilot; you r correct, Onan recomments 250 hr oil change on diesel units, which is ok on the tough -as-nails Kubota diesels (and Izusu 10 years ago) But the gasoline units are air-cooled, run hot as h***,
and only hold 2 qts in crankcase. The 4000 w only holds 1.5 qt and has no filter. Personally, I recommend 100 hr changes, or annually, as oil is much cheaper than repair parts

DAMN ! 150 hr oil change interval !?!?! I thought NG burned cleaner.
I thought Our QD10k calls for 250hr change intervals was brief !

yep....engineers rarely design with a view towards the poor sap who actually has to repair these things. we use a lot of never-seize at our shop, when putting these things back together. And I'm sure you know this, but never run for more than a minute or two without service door installed, exhaust system will quickly overheat without door on. Oil change interval per Onan Op Man., is 150 hr or annually

I looked at disconnecting from the outlet box but couldn't figure out how to feed it all back in without ripping up the interior, mostly the bath vanity. Then I would have had a big long pig tail to work around.

Top rotor bearing wouldn't budge to the point I was afraid of busting the housing. There's a metal cap at the top I could have pried off but didn't see any available replacement caps.

I greased a lotta bolts on re-assembly, but didn't replace with stainless. The replacement mounting bolts that sheared are a grade higher (8.8). The front originals sheared pretty easily - just behind the rear wheels - imagine that.

The mounting bolts appeared to be 10mm x 16 threads/in. 1.5mm pitch didn't match and a 3/8 bolt wouldn't thread into the back holes. Pretty crazy. I ended up drilling and tapping for 3/8-16. Perfect, just don't mix them up with the back set.

This Fleetwood was registered in IN from 2002-2009 and ~65k miles. I get a queezy feeling they used it for snowmobiling and not summer camping as the chassis shows it. You learn so much after your first purchase LOL

Best,
- c bob

I have not been on this web site for couple weeks, but as I started reading this thread, I guessed you had bad lower rotor bearing by way you described noise. Is good idea to replace both bearings when doing that repair. And replacing drive belt is also cheap insurance. Unfortunately, steel on aluminum causes bolts to feeze up and break, esp. in areas high in road salt usage. And disconnecting a.c. wiring and conduit is usually done at connection box, not at generator, but your particular unit may not have been easier to do that way. Congrats on your successful repair.

cbr46 wrote:
Project is complete. Genny is returned to it's bay and purring like the kitten it is.

6 sheared bolts. That was fun. None of them came out with an extractor, even after days of PB Blaster and heat. They had to be drilled and re-tapped.

Bottom rotor bearing was the main problem with 1/3 of the balls missing, bearing cage chewed up and both bearing covers off. It's a pretty standard 6205 ball bearing. The bearing wouldn't come off the shaft, even with the help of my local NAPA machine shop. I ended up cutting it off with a dremel.

And if anyone needs to replace the fuel filter it's NAPA item 3046 - $4

Happy camper again.

Best,
- c bob

Great work. Once you said the oil was good, then it had to be something other than the engine. A generator is basically half engine and half generator. In your case, the generator rotor bearing failed and caused things to seize. I'm sure that you saved yourself a lot of money.

Project is complete. Genny is returned to it's bay and purring like the kitten it is.

6 sheared bolts. That was fun. None of them came out with an extractor, even after days of PB Blaster and heat. They had to be drilled and re-tapped.

Bottom rotor bearing was the main problem with 1/3 of the balls missing, bearing cage chewed up and both bearing covers off. It's a pretty standard 6205 ball bearing. The bearing wouldn't come off the shaft, even with the help of my local NAPA machine shop. I ended up cutting it off with a dremel.

And if anyone needs to replace the fuel filter it's NAPA item 3046 - $4

Happy camper again.

Best,
- c bob

Suggest finding an Onan shop to get you out of your mess before you destroy what is left. These are simple units IF you know how. Have seen more than one unit destroyed by a well wisher wannabes.
Good luck.
Dave M

Went to GREAT effort to take the engine down to splitting the cases only to find . . . . nothing. Everything looked fine. Crank non-bearings, cylinders, cam lobes, no oil on either plug. A complete mystery.

Then I spun the armature and it made this very audible warbling noise. Dang, but at least we can rule out oil failure! :S

I did ruin one of the valve cover gaskets. Guess I'll have to make a replacement?

Best,
- c bob