Suburban SF30 Furnace

[mdriver1]

Hi,
To start Merry Christmas to rv.net members. First time poster here.
Suburban SF30 furnace in a 2006 Gulfstream Innsbruck (bought used)

Question:
Has anyone seen the air wheel (#350184) on the blower motor get warped? It's plastic and appears to be in decent shape (not broken or missing vanes, tight on shaft, etc.) but is rubbing the housing it sits in and not true while spinning (very visible warping), therefore making a terrible noise. Took motor out, air wheel and squirrel cage off and motor seems quiet. Shaft is a little tight by hand turning but not sure how these motors are supposed to "feel" by hand turning. In a little bind as it's somewhat cold here in TN but this week is quite warm. A good time to fix this. I see the motor does come apart and am wondering if it's worth the time to replace bearings or buy a motor? My experience with other motors (lathes, etc.) usually points to bearings. Very rare to see a shaft warped.
Sorry for the bombardment of questions but don't wish to spend more money than necessary to get back to heat when the cold does come back.
Thanks,
Mark Driver
Knoxville, TN

[mdriver1]

Wow. I can see that with the ports being open.
A direct avenue to a chambered haven! lol.

Thanks

[CavemanCharlie]

If you have it removed from the TT and are rebuilding it make sure you get all of the Wasp/Mud Duber nests out of the combustion chamber !!

Those wasps love to build nests in there and plug things up. I once removed a furnace that was not working right and dumped a whole coffee can full of nests out of it.

You may have to figure out a way to dig gently around in there and brake them loose.

[mdriver1]

Appreciate the input as I value folks with experienced advice.

Thanks

[N7SJN]

After 40+ years of RVing I have learned to replace with the most reliable parts so that is why I mentioned the Dinosaur board.

[mdriver1]

Thanks.
Dinosaur board on the way

[N7SJN]

Don't forget the control board. I had two of them go out before I had a Dinosaur board installed. The boards are made in Lincoln City, OR.

[mdriver1]

Thanks for the input. Yes I thought of that.
The plastic wheel was a bear to get off. Lubed it up and came off after several tries.

I do see that the motor has 2 lock nuts for adjustment. Maybe they vibrated a little causing the motor to "shift" towards inner housing a little?

Just a thought. Since it's a 2005 furnace and torn apart, have decided to rebuild. Switches, motor, etc. Much cheaper than a new one. Don't want to put all back together to find something else breaks especially when it gets cold.

Thanks

[CavemanCharlie]

Since it is plastic could it have been just stuck on the shaft crooked ?

Can you just bend it back to a straighter position ?

Maybe try sliding it back in to the correct position and see if it still wobbles as bad as what it did before.

[prichardson]

If there is vibration replace the blower wheel. Note that even the new wheel may not be square and have some wobble.

[mdriver1]

Thanks for the replies.

Yeah I'm leaning towards a new wheel as well.
Shaft is solid from side to side as well. Forgot to mention that in original post.
The wheel wobbles about an 1/8" out of visible straight line of site.
I'm going to check the shaft run out tomorrow morning but visibly looks fine.


Yes they seem to be put together rather quickly and cheaply. You're right we keep buying them though. Ha! I use mine for work out of town. Travel and stay in RV 3 nights per week and work from home some. I love my travel trailer though. Quite cozy and serves the purpose well. Better than a dang hotel room for sure. Need to go bigger on propane tank though. My 2 30's aren't cutting it. Lucky there is a refill station on way home from work to camper.

Thanks

[enblethen]

The fans will wobble a little. Best you can do is adjust the fan blade on the shaft so it clears.
The fan motor will have some restriction in turning by hand.
Move the bare shaft around side to side. If there is no slop in the bearings or bushings put it back in the furnace. I would write down the exact model number for future reference.

[wrgrs50s]

I would be willing to bet that all your noise and vibration is the plastic blower wheel and the motor is fine. If there's no visible warping on the shaft and the motor runs quiet just purchase a new blower wheel. Since it's plastic I would double check the new one before assembling everything.

What a crock that they make everything so cheap on an RV. I think the industries goal on RVs is to make it good enough to last the warranty and after that they're assured to make extra income on parts and repairs. What can I say though we all keep buying em ! LOL