# Convection blower bearing replacement.



## Jason Knapp (Jan 5, 2014)

I thought I read a while ago that there was someone on this forum who replaced Fasco blower motor bearing with a better quality bearing. Any idea who that might be?


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## Mt Bob (Jan 5, 2014)

Might have been me,what number bearing do you need?


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## Jason Knapp (Jan 5, 2014)

The bearing I need:  NMB 608SSD21. I need 2 of them but would prefer a better quality piece.


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## Mt Bob (Jan 5, 2014)

Those bearings are very high quality stainless steel.Must be a convection fan.You can get cheaper ones,but may be noisy.Look for german or japan made.Some of the manufactures are having the smaller bearings made in china for cost,but still offer the higher quality.Hope this helps


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## Jason Knapp (Jan 5, 2014)

The ones I have now are made in Singapore. They didn't last too long. Im hoping to find really good ones. Ill Google it and see. 
And yes its for a convection blower. There was someone on this forum that offered a replacement service.


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## Woody1911a1 (Jan 5, 2014)

try grainger , msc or mcmaster-carr


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## Mt Bob (Jan 5, 2014)

I have standard german 608 sheilded,no stainless.You may be able to get bosch bearings at fastenal.Or look for router bearings.


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## Jason Knapp (Jan 5, 2014)

I was able to find a 608 bearing through SKF. It's an ABEC 1 rated unit, so I think it can handle 2500 rpm easily.


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## Mt Bob (Jan 5, 2014)

I have a bunch of 608's but yours was ss-stainless steel.ABEC 1 is the lowest rating for tolerance.Most convection and combustion 608's I have seen are abec 3.If you do not mind shielded instead of sealed go to ebay,look for gmn "old school skate board bearings".These were made in the 80's-90's before skateboard bearings were made-low rolling resistance.These are german new old stock,and you can get a handful for $10.These came stock in austroflamm motors.They are 608-gmn-3.ABEC 3 which is a trade off of tightness yet allows for heat expansion.They are not stainless steel


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## Jason Knapp (Jan 5, 2014)

There are a lot of the NOS 608's!
Do you have to lube them? If so, what do you use?
I ordered a set of sealed greased units to see how it goes. Yes they are only ABEC 1, but given that they wont see a ton of axial load, I was thinking they may be OK. Also the looser tolerances may be more tolerant of heat. Just my thinking. I have the time to mess around and see how it goes. Thanks for the input. I will keep you posted.


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## tjnamtiw (Jan 5, 2014)

The looser tolerance bearings would do well in the combustion blower but IMHO won't see much heat on the convection blower so you're probably OK on the ABEC 1.
Note to self> file this one away for future reference.


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## flybmw02 (Jan 5, 2014)

I have changed bearings  many times they get loud and there done. This guy on ebay sell good bearings cheep. good luck.
John
http://www.ebay.com/itm/2-608-2RS-p...=BI_Heavy_Equipment_Parts&hash=item1e73ded7f4


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## KodiakII (Jan 5, 2014)

Is it ok to cut the little buggers off the shaft?  I don't have a puller that small.


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## WiscWoody (Jan 5, 2014)

I have cut bearings off before. Are you going to used a cutting wheeled grinder?


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## KodiakII (Jan 5, 2014)

hermancm said:


> I have cut bearings off before. Are you going to used a cutting wheeled grinder?



Probably will use a air die grinder with a cutting wheel on it.  If I nick the shaft I can fix it with some weld and grinding.


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## WiscWoody (Jan 6, 2014)

If it's a small nick you should be fine. You can cut it close to the shaft and hit it some it might loosen enough to pull it.


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## Jason Knapp (Jan 6, 2014)

tjnamtiw said:


> The looser tolerance bearings would do well in the combustion blower but IMHO won't see much heat on the convection blower so you're probably OK on the ABEC 1.
> Note to self> file this one away for future reference.


 
I am ceratinly hoping so. As far as temps, this blower gets HOT! I put some heat shielding around it which seems to help, but I would like to replace the bearings in the original unit so it,s ready to roll if I need it.


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## Mt Bob (Jan 6, 2014)

Jason Knapp said:


> There are a lot of the NOS 608's!
> Do you have to lube them? If so, what do you use?
> I ordered a set of sealed greased units to see how it goes. Yes they are only ABEC 1, but given that they wont see a ton of axial load, I was thinking they may be OK. Also the looser tolerances may be more tolerant of heat. Just my thinking. I have the time to mess around and see how it goes. Thanks for the input. I will keep you posted.


 Yes they are grease packed-the german ones-which is why skatboarders no longer use them,they are using oiled bearings.


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## Mt Bob (Jan 6, 2014)

Jason Knapp said:


> I am ceratinly hoping so. As far as temps, this blower gets HOT! I put some heat shielding around it which seems to help, but I would like to replace the bearings in the original unit so it,s ready to roll if I need it.


 ABEC 1 are looser,higher the number closer the tolerance,hence less noise and vibration,but less able to deal with expansion,3's standard for most blowers,5 or 7 for precision equipment.


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## flybmw02 (Jan 6, 2014)

I would use a Dremel  type 3/4" cut off wheel to cut such a small bearing very easy to control.


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## WiscWoody (Jan 6, 2014)

Now my wood stove blower has started having a bearing noise. When it rains it pours huh?


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## WiscWoody (Jan 6, 2014)

bob bare said:


> ABEC 1 are looser,higher the number closer the tolerance,hence less noise and vibration,but less able to deal with expansion,3's standard for most blowers,5 or 7 for precision equipment.


Bob- I always thought it'd be nice to live in the Rocky's  It sure is scenic there! And Helena forest is close as well as some others, Nice!


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## Roadstar (Jan 6, 2014)

Jason Knapp said:


> I thought I read a while ago that there was someone on this forum who replaced Fasco blower motor bearing with a better quality bearing. Any idea who that might be?



I have to ask. How did you ever get the squirrel cage off?

I assume your Fasco blower has a squirrel cage. I have about three Fasco blowers sitting in the garage that need bearing replacement but I'll be damned if I can get the set screw loose. Whenever I try it looks like my allen wrench is going to break.


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## rickwai (Jan 6, 2014)

KodiakII said:


> Is it ok to cut the little buggers off the shaft?  I don't have a puller that small.


If you are replacing bearing on your Greenfield double squirrel cage fan you can use a large puller. I just did this on mine and used my 2 jaw puller that has larger jaws. I had to hold the jaws under the bearing to keep them from slipping off but it worked. It does not take much effort to get them moving, I did not even have to use a wrench on pulled. They only need to come up about 3/4 inch before they are free on the shaft. I bought a 1/4 inch by 5 inch brass pipe nipple to drive bearing back onto shaft. Fits perfect so you are not driving against the plastic grease seal.


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## Jason Knapp (Jan 6, 2014)

Roadstar said:


> I have to ask. How did you ever get the squirrel cage off?
> 
> I assume your Fasco blower has a squirrel cage. I have about three Fasco blowers sitting in the garage that need bearing replacement but I'll be damned if I can get the set screw loose. Whenever I try it looks like my allen wrench is going to break.



I used a little bit of heat on the set screw and it was easy from there. It took a little elbow grease to get the cage off of the shaft, but it came free without damage.


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## rona (Jan 6, 2014)

I would go to your local electric motor rebuild shop and get the ones made for heat. They have the right lub in them and will last a lot longer. I tried the cheap skate bearings and they only made a couple months


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## Mt Bob (Jan 6, 2014)

hermancm said:


> Bob- I always thought it'd be nice to live in the Rocky's  It sure is scenic there! And Helena forest is close as well as some others, Nice!


 I live above bozeman pass 6500,lots of snow plowing.This is in the bridger range of the gallatin forest.We do pay dearly to live here,well known to be a double tax state!The forests around helena are all almost standing dead from pine beetle kill.


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## Mt Bob (Jan 6, 2014)

rona said:


> I would go to your local electric motor rebuild shop and get the ones made for heat. They have the right lub in them and will last a lot longer. I tried the cheap skate bearings and they only made a couple months


 We are talking about new old stock german motor bearings that used to be used for skateboards before cheap board bearings came out.


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## KodiakII (Jan 9, 2014)

Picked up a set of bearings today.  Cost me a whopping 8 dollars and change.  I am having some misgivings about them...they are made in China.  Should I look for a better brand or slam them in and let er ride?


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## tjnamtiw (Jan 9, 2014)

KodiakII said:


> Picked up a set of bearings today.  Cost me a whopping 8 dollars and change.  I am having some misgivings about them...they are made in China.  Should I look for a better brand or slam them in and let er ride?


Do it to it  EVERYTHING IS MADE IN CHINA! Even Bosch car parts, Milwaukee power tools, you name it!


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## rona (Jan 9, 2014)

KodiakII said:


> Picked up a set of bearings today.  Cost me a whopping 8 dollars and change.  I am having some misgivings about them...they are made in China.  Should I look for a better brand or slam them in and let er ride?


Just as well put them in and try it.  Like anywhere else some peddle junk and other companies in the same country have good stuff. quality control makes the difference. If you look into it most of the pellet stoves electric boards are Chinese made. The popular Quadrafire AE  has a Chinese board among many other brands.. It all boils down to where a product can be manufactured the cheapest.  The cast iron parts on a AE are also foreign made.
   Not picking on the AE  but I used to own one and if you looked at the electric board it was stamped Beijing, China.


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## Jason Knapp (Jan 10, 2014)

These bearings I just got have Germany written all over them. I'll report back with any info.
I was incorrect earlier, the bearings I got are an ABEC 3. I'm pretty excited!!


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## Harvey Schneider (Jan 10, 2014)

Roadstar said:


> I have to ask. How did you ever get the squirrel cage off?
> 
> I assume your Fasco blower has a squirrel cage. I have about three Fasco blowers sitting in the garage that need bearing replacement but I'll be damned if I can get the set screw loose. Whenever I try it looks like my allen wrench is going to break.





Jason Knapp said:


> I used a little bit of heat on the set screw and it was easy from there. It took a little elbow grease to get the cage off of the shaft, but it came free without damage.


Heat the hub not the screw. That makes the hole the screw is in expand. At the same time the hub expands on the shaft and makes it easier to move.


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## Jason Knapp (Jan 10, 2014)

I should have been more clear in my removal technique. I should have specified heating the hub itself..... heating the set screw will do nothing but expand it in the hub, and probably get the person removing said set screw even more aggravated.


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