replacing blower bearings

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maverick06

Minister of Fire
Sep 27, 2008
827
media, pa
I hope the below to be helpful to someone:

I have a fireplace extraordinaire (with a different face it is sold as a lopi declaration). And it was time to service the blowers. for those unfamiliar this is a flush mount stove with a pair of blowers under it. I bought the stove new in 2006, and by 2013 they were making lots of noise (estimate 20-25 cords of wood). I was able to get a new pair then. These are Part: 171-01010 (actually that seems to be an old part number, the new one is 228-10069). When I replaced the blowers in 2013 they were $60-$120 each. I bought $60 ones and they were identical to the originals. I was amazed how quiet the new ones were, they probably should have been replaced a long time ago.

However, it bothered me spending so much for the blowers, and I was concerned how much longer I could get replacement parts. Now, in 2016, the new ones are occasionally making bearing noises. but since they are working fine, I figured it was worth tearing into the old motors. Below is a picture of one of the the "old" and "new" motors.

img_7829-jpg.97917.jpg

the motor and squirrel cage is held onto the bracket (piece with rubber grommets) by 6 pop rivets. I drilled out these rivets.
Then the motor can be twisted about 20 degrees to separate from the squirrel cage unit. The motor shaft is just friction fit to a rubber piece on the blower (left side). The right side of the squirrel cage has a metal stud going into a metal bushing.

Fixing it:
I used spray lithium grease for the metal bushing.

The motor required more work. There were 2 screws in the c frame motor that hold the two bearings on either side. Unscrewing that lets you remove the bearings and the motor shaft. The motor shaft is a shaft, motor rotor with a bearing on either side of it. I was able to pull the bearings off the shaft. This was hard as the bearings were very close to the armature. I tried tapping it out, and found the shaft could move in the armature. This was annoying as I had to re-tap the shaft back to the right location. Next time I will be more careful with the bearings.

Once the bearings were off the shaft, I chucked the shaft into the drill and used a greenie pad to scrub the rust and whatnot off of the shaft.

The bearings turned out to be 608 bearings, these are generic roller skate bearings. Super available and cheap! I ordered many replacements.

http://www.ebay.com/itm/191034440705?_trksid=p2060353.m2749.l2649&ssPageName=STRK:MEBIDX:IT
http://www.ebay.com/itm/391385140321?_trksid=p2060353.m2749.l2649&ssPageName=STRK:MEBIDX:IT
http://www.ebay.com/itm/161807909080?_trksid=p2060353.m2749.l2649&ssPageName=STRK:MEBIDX:IT

Of those I was only pleased with these:
608rs7-grn-4.jpg

four bearings for $5. The others were a mess. They were very heavily greased. I put them in one of the motors and the motor could barely spin there was so much friction. These green ones work perfect and are very quiet.

There was a tiny gap between the bearing and the rotor. Not enough of a gap to feel any movement, but enough that it would spin relative to the shaft. A drop of blue locktite fixed that when I replaced them.

Bearings:
Bearings are rated by their ABEC rating. The higher the number, the better the tolerances and less slop in the system there is. So in this case a higher number is probably better. Keeping the unit quiet. Bearings can be rated as 608RS or 608ZZ The RS is for a removable seal. The ZZ is for a removable shield. The shield is not going to seal the bearing. Since I wanted to keep the ash dust out I went with RS. One set of bearings was stainless steel. This would be better, the originals had some corrosion in them, clearly what caused the failure. This was probably just humid air. The stainless steel ones also had too much friction and I am not using them.

BUT

the 2 of the lots of bearings had very high friction, with the grease. These might be fine for more powerful units, but not for this. You can pop the seals off, soak the bearings in a solvent to get rid of the grease, and replace with a better lube. I have done that but am not thrilled with the results yet. The green ones worked great out of the box, didn't mess with them.

Putting it bath together was simple, reassemble the motor, connect the squirrel cage to the motor, put bolts/nuts with locktite where the pop rivets were, and back in it goes.

lessons learned.
don't tap out the bearing when it is still in the bearing housing, the housing is cast material and easily cracks. JB weld fixed that just fine.

don't try to tap out the bearings bracing the rotor, the shaft will move relative to the rotor and it will be out of alignment. be more careful to press the bearing against the shaft.

Use locktite to hold the bearing to the shaft if there is a nominal clearance, a press fit is better of course.

The rating of the bearing might not be of much value, if they are made in china it could be a lie. And even with good tolerance the grease could make it nonusable. These are cheap enough I suggest ordering a few different lots so you can test them out, and plan to be able to regrease.

have a spare set of blowers on hand. I can now swap them out in a matter of just a few minutes. Beats having to do all the work during heating season.

Even though the blowers work "fine" replacing the bearings can really quiet them down, they seem to slowly make more and more noise you might not see them getting bad.

There might be a more elegant way to do this, but for $2 of bearings, its way cheaper than buying new motors.
 
Good info, thanks for the detailed post.
 
Thanks, took me a while to figure it all out, and seeing the prices that are charged for new units when chances are some cheap bearings are just bad, its an easy fix.

For removing the rivets. You can use a hammer and nail and knock out the center of them easily. Then drilling the remainder out is very easy to do.
 
You will learn quickly that commercial products almost always use commonly available bearings. Custom short run bearings are stupid expensive and rarely purchased. Any smart manufacturer will find out what is available and design around that because the cost is so much less.

My cousin and I were on a motorcycle trip in WV Memorial day weekend. His rear bearings start to go on his '96 CBR600 motorcycle. We swing into the only powersports place in town at 4:30pm. No dice. They don't have the parts. However, the parts guy was smart enough to pull the drawing, grab the OD and ID and match it to a dirt bike bearing. Perfect fit. We changed them in a Walmart parking lot and back in business for the remaining 1,500 miles of the trip.
 
Thanks for your detailed information - this is super helpful! Do you think someone who's not so handy could handle this as well?

Also, 73Blazer posted similar findings as seen in his detailed thread below. He - like you - was trying a bunch of different bearings. It would be interesting to hear what his findings have been since then...

Matt


https://www.hearth.com/talk/threads/rebuilding-blower-fans.148549/#post-1997963
 
HAHA oh man i wish i saw that thread before doing all this!

Yeah, you can do it, if you own a hammer, locktite, and a drill you have almost all the tools needed. A bearing puller is helpful too, but you can do it without it. Wait until you have some extra time to do it slowly. Remember someone built this, so just figure what they did in reverse.
 
Mav, i have 1 thats trying to get a bit noisy. Had one on my Dutchwest that i was able to open up and add a couple of oil ports which i made up from some small brass hobby tubing. That worked great and only had to add a couple drops of oil a couple times a season. It would let you know when it was time to do so as well. Going to have a look at my current one when the season is over. Thanks for sharing the info...... rn
 
Awesome post....I have the same blower and just ordered a pair of replacement blowers (L and R) for my woodstove, however I will attempt to "fix" the original ones so I have backups....
My first attempt will be to get a syringe loaded with machine oil to inject into the original bearings. Has anyone tried this method?

If that does not work I will disassemble the blower as you indicated above and replace the bearings....
I will order the bearings you recommended above (green ones), but before I order, are these still the best ones for this blower or does anyone recommend different ones? I seen some ceramic ones and hybrid ones too, any suggestions are greatly appreciated....

Also looking for the red rubber end grommet/washer as seen in the pic I attached, as one of mine is damaged!!!!!
 

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Clean the blowers good every other year at least. Will save the life of them.
 
I'm looking for the red rubber grommet in the photo I attached....Does anyone have an idea of where I can find one.....
 

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I remove, and clean my blower with compressed air every fall before the burning season. I am stunned at the about of dust and all other nastiness that comes out. Keeping your fins clean with improve your efficiency and performance as well. Try Simple Green, just keep it out of the motor housing and electronics. Eats the grime right away. After rinsing, let it dry for a day or so in the sun to cook off any moisture.
 
The green bearings, I have had one set in service since the fall, still working good.
I read good stuff about this vender, so i bought some of these, I havent yet put them in service:
http://www.ebay.com/itm/Qty-2-608-2...608-ball-bearings-608-RS-ABEC3-/130793002996?

They are so cheap its ok to have a few extra laying aroung.

I do not know what the red grommet is, i would buy a spare if i could. BUT I know how to get it out.

Carefully put a flat tip screw driver in by the cage and push the plastic out, go slowly and it will come out, or at least mine did, do at your own risk. Put push with the screwdriver, dont pry them out.

Inside the red rubber is a sintered metal bushing. I *think* it is OD: 11mm, ID 4mm, length 8mm. I can not find a good place to buy them, if anyone knows please let me know. you definitely have to take these out and clean them, qtips and oil work good. I tried using ball bearings for them. I used these guys and a little spacer since they arent the same length:
http://www.ebay.com/itm/10Pcs-694Z-...-Groove-Ball-Bearing-Silver-Tone/311673312448

It was super quiet for about 30 min, then made a lot of noise. Tried another bearing, did the same thing. Might be better if i change the grease, didnt experiment yet. Would really like to get replacement bushings. They should be cheap, just cant find a place to buy them....
 
I managed to drill out the 4 rivets and separate the cage/motor from the housing, however I am stuck on getting the motor to detach from the cage.....can someone help me to the next step?
 
The motor is held to the blower assembly by, if I remember, 4 tabs. You have to twist the motor to blower shield counterclockwise. Then you can take them apart. The motor shaft is then connected to the blower with a friction fit, just pull it off.

BUT

that's how mine was done... I have no idea how yours is built, or if they changed assembly processes.

Also, I have had the bearings go, as discussed above. Just remember to clean and lubricate the bushing. Should be good after that. If you post pictures we can confirm that.
 
The motor is held to the blower assembly by, if I remember, 4 tabs. You have to twist the motor to blower shield counterclockwise. Then you can take them apart. The motor shaft is then connected to the blower with a friction fit, just pull it off.

BUT

that's how mine was done... I have no idea how yours is built, or if they changed assembly processes.

Also, I have had the bearings go, as discussed above. Just remember to clean and lubricate the bushing. Should be good after that. If you post pictures we can confirm that.

I trusted your post, seen the 4 tabs you spoke of and gave it a good twist.......finally it came apart.....Thank you!!!!!
onto the next step!!!!!
lol

Just need to find another red rubber piece that covers the metal bushing as mine is damaged....any ideas for that?
 
Great that you got it off!

I have one thats damaged too, nope, dont have a solution there. If you find one let me know! Probably could patch the tear with some glue. Superglue sells a few glues that are designed for rubber-y things. Maybe something like this:
http://www.loctiteproducts.com/p/sg_ug_cntrl/overview/Loctite-Super-Glue-ULTRA-Gel-Control.htm

I havent tested that. Would prefer a replacement, its a piece that probably costs a nickel, like the bushing. I would like to replace both, but havent found a source.
 
Jotul replacement blowers are close to $200. Makes me throw up

Been lucky so far, havent had to replace the bearings, but i do clean them once a month and oil the bronze bushing on the opposite side. Not sure if you have that bushing as well. Hopefully your blue loctite works for that, i dont remember max gap for the blue. The better loctite for that app is 603, though im lucky i have access to it at work.

My biggest thing is the red plug/bearing holder which holds the bronze bushing, anyone know where i could find that. Over the years it is getting cut up
 
The other option for the red grommet is to go to ebay, buy a generic fireplace blower, they are about $20, and hope the pieces are interchangeable with yours. Again, not the right solution but it might work. I am sure the fireplace companies aren't manufacturing these gromets, just have to find a source for them and the bushing inside.
 
FANTASTIC thread, thanks be to Maverick.

In the bearing market as well since my last cleaning
generated a HUGE difference in overall performance
but the bearing issue will not drop.

End season will include a new pair for each motor.
 
A great source for mechanical items is mcmaster.com. For electrical components, try digikey.com. Both of these companies have a great selection of quality items and ship fast.
 
Just to revive this thread for the sake of sourcing those rubber grommets:

GHP has been listing these as "sold out"...call them directly to see if they are in stock. just ordered some today via telephone.