# Changing bearing in Dewalt miter saw



## UpNorth (May 17, 2007)

I wrecked mine today when cutting some warped framing lumber.

The bearing only costs about $8, but to get it off, I need a puller, and to get it on, I may need an induction heater. These are shop tools I do not own. In short, I need a qualified repair shop, and one is nowhere near me.

What do you do?


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## griz (Nov 26, 2009)

Buy a new saw?:whistling

No mechanic around with a puller/press?

Come on North, think about.....

More than one way to skin a cat:thumbsup:


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## WarnerConstInc. (Jan 30, 2008)

puller is like 10 bucks for a cheapy.

I am sure you have an oven and a freezer, you should be set.


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## TimelessQuality (Sep 23, 2007)

WarnerConstInc. said:


> puller is like 10 bucks for a cheapy.
> 
> I am sure you have an oven and a freezer, you should be set.


:thumbsup:


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## pinwheel (Dec 7, 2009)

Pull the armature out & take it to the local machine shop & have them press the old one off & the new one on. Cost me $5 & them 5 minutes on my last one.


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## UpNorth (May 17, 2007)

Ordered the bearing, watched the YouTube video showing how to score the old one and crack it off with a vise. Or at least the outer race. The balls and keeper come off readily then, but it takes a puller to get the inner race off. I'm sure the new one will need to be heated to go on.

Now for a puller and some heat. This ain't rocket science, but if one has not done it before, it can seem a bit of a challenge.

Gonna ask around to see if some of the auto shop guys know someone willing to do this pull off and replace thing.

Problem is, I live in a small remote village. It is an hour's drive to the nearest WalMart, and there is really nothing happening, machine-shop-wise, where I am. The nearest repair shop for tools like this is over in the next state, a long drive, including an expensive ferry round trip. By the time I go there in my truck and drop it, then do the same a week later to pick it up, I am well into the cost of a new saw.


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## alexjones (Jun 29, 2011)

Yep! I gotta make it my bible!


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## Railman (Jan 19, 2008)

Any decent auto shop should be able to do this for you, as long as they are not busy, & compensated. Even a small arbor press should do. That will be your best bet.

You could probably just use an 8" or so C clamp as a press. I've done it that way before, but it depends on the bearing tolerance. Find a deepwell socket, or tubing to press the center race squarely.
As mentioned by others, you can probably cut old bearing off with a dremel, die grinder, or plain old bench grinder. Just be carefull not to nick the armature wires, or comutator. Tape/mask, or cut a plastic bottle to cover & protect the armature. When you get down to the center race, cut on a diagonal ( or do bench grinder) & pop with a screw driver when the cut is close to the shaft. A small nick in the shaft won't hurt much if it does occur. just clean up marks before installing new.
Joe


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## TBFGhost (Oct 9, 2008)

You shouldn't need heat...I have never needed heat. They are press fit, but it ain't that tight of a press fit...I am also wondering how cutting bad lumber killed your armature bearing....I am more then willing to be they were already on the way out.


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## PrestigeR&D (Jan 6, 2010)

What ever you do DON'T heat the rotor shaft up......

Heat the bearing up with some MAP gas, or propane if you don't have any with a plumbers torch, Your going to have to come up with some type of sleeve bushing/plate to go behind the bearing to cover the span in-between the jaws of a bench vice. Once the bearing is warmed up and not severely hot (moving the flame point from the torch nozzle around the bearing- the outside race-Only, it will transfer the heat up to the inner race through the steel balls in-between) 

Once it's hot, move it into the sleeve pocket , grab a hardened point al and tap the rotor shaft and it should start to move up the shaft for you.


hard to explain without drawing it out.

Anyways
when you get it off, take the rotor and find some room in the freezer for it- leave it in there for 1hr. In the mean time get your torch ready again, along with the new bearing ready to go, once the rotor shaft is ice cold - now your ready to heat up the bearing- out side race again, lightly heat the bearing- once it's fairly hot , grab the rotor shaft out of the freezer , get it clamped up "carefully" in the bench vice with the shaft resting on the bottom of the vice, set the bearing on the top shaft, grab a deep socket (slightly larger size of the inner race) and start to tap the bearing onto the rotor shaft to it's desired position. It should go on fairly easy with little force needed while your tapping it down. 

I used this method on my 2-1/4" OD x 28"L spindle shaft-4 bearings, large bearings :laughing: and it went well :thumbup:

Give it a go. I hope you have some success with your repair...:thumbsup: 

B,


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## tgeb (Feb 9, 2006)

UpNorth said:


> The balls and keeper come off readily then, but it takes a puller to get the inner race off.......


A cold chisel tapped into the inner race, (at 90 degree angle to the shaft), will expand the race and it will/should come off easily.

Brian has described the rest of it to a "T". 

Just don't stop mid-way and take a break, get the shaft cold, the bearing hot.....and go for it.

I have a week end project coming up, involving bearings, that I am considering some dry ice for....


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## PrestigeR&D (Jan 6, 2010)

tgeb said:


> A cold chisel tapped into the inner race, (at 90 degree angle to the shaft), will expand the race and it will/should come off easily.
> 
> Brian has described the rest of it to a "T".
> 
> ...


Yea Tom.-:thumbup: I totally agree, the colder the better- anyone have any liquid nitrogen :laughing: Good point... colder the better!:thumbsup: 

B,


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## UpNorth (May 17, 2007)

Thanks for the detail.

Here is a screencap showing the bearing on its shaft, and note that it is almost tight to the fan. The vid shows the two step process of removal, the first being to use a Dremel to score the outer race, one nice deep cut and another at 180 across, then a vise is used to break it off. The balls and keeper come out readily then, and a small puller can be tightened onto the inner race for the pull.

I wish the guy had shown fitting the new bearing to the shaft.


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## CO762 (Feb 22, 2010)

UpNorth said:


> Problem is, I live in a small remote village. ...the cost of a new saw.


I'd buy a new saw and use the old one for parts. There's something to be said for redundancy in some situations.


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## Brad 1 (May 26, 2011)

You're making this far more complicated then it is. First buy one of these as they are cheap. Most auto parts stores or Harbor Freight have them. 

http://www.google.com/products/cata...a=X&ei=33MMTpKtDrPDsQLpxNCmCg&ved=0CHcQ8wIwBQ

And do NOT heat anything. The bearings are not on THAT tight. They are a mild friction fit. Once you have the separator clamped tightly underneath the bearing, rest the separator on a vise and use a hammer and punch to knock the end of the armature through. Be ready to catch the armature when it drops off of the bearing so it doesn't hit the floor. Installation is also easy. Open the vise jaws just big enough to clear the armature shaft, place the bearing on the end of the shaft (the bearing is sitting flat on the vise jaws), and use a hammer and drift to hit the armature shaft until the bearing is fully seating. It's that easy really. I have done hundreds, if not thousands this way.

And there is no need to "score" the outer race. On bearings that are too close to the fan just place the bearing in the vise and tighten it until the outer race breaks. They are hardened and you can break them pretty easy this way. Then you can use the separator in the middle of the inner race, where the od is smaller, to remove it just as you do a complete bearing.
:thumbsup:


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## TBFGhost (Oct 9, 2008)

UpNorth said:


> Thanks for the detail.
> 
> Here is a screencap showing the bearing on its shaft, and note that it is almost tight to the fan. The vid shows the two step process of removal, the first being to use a Dremel to score the outer race, one nice deep cut and another at 180 across, then a vise is used to break it off. The balls and keeper come out readily then, and a small puller can be tightened onto the inner race for the pull.
> 
> I wish the guy had shown fitting the new bearing to the shaft.


Use a deep socket to drive the bearing on. It should tap on fairly easy. Use a socket that fits over the shaft, but will rest on the inner race. You want to drive that bearing on by the inner race.


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## TBFGhost (Oct 9, 2008)

CO762 said:


> I'd buy a new saw and use the old one for parts. There's something to be said for redundancy in some situations.




For what amounts to half hour to an hour of work and a few bucks in parts?


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## TBFGhost (Oct 9, 2008)

Brad 1 said:


> You're making this far more complicated then it is.



:thumbsup::thumbsup::thumbsup::thumbsup::thumbsup::thumbsup::thumbsup::clap:


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## CO762 (Feb 22, 2010)

TBFGhost said:


> For what amounts to half hour to an hour of work and a few bucks in parts?


It's turning out to be more than 1/2 hour so far..... 

I've seen more people waste more time tinkering with things to get/keep them running instead of just buying a new one. What goes thru my brain is, "Just get another one and put it to work, making you money instead of spending so much time and energy on trying to save money". But some guys are just mechanic/tinkerer types and some aren't. I'm not.


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## 3bar (Jan 14, 2011)

CO762 said:


> It's turning out to be more than 1/2 hour so far.....
> 
> I've seen more people waste more time tinkering with things to get/keep them running instead of just buying a new one. What goes thru my brain is, "Just get another one and put it to work, making you money instead of spending so much time and energy on trying to save money". But some guys are just mechanic/tinkerer types and some aren't. I'm not.


some people trip over dollars, to save pennies.


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## Tom Struble (Mar 2, 2007)

some guys enjoy fixin their stuff who cares...

it's not always about money


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## TBFGhost (Oct 9, 2008)

3bar said:


> some people trip over dollars, to save pennies.



If people justify everything they do in their life by first determinnig if it makes them money or not, I suggest they take a long vaction.


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## Tom Struble (Mar 2, 2007)

and some guys don't know the difference between a machine screw and a lag bolt:clap:......who's next?:thumbup:


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## CO762 (Feb 22, 2010)

Tom Struble said:


> some guys enjoy fixin their stuff who cares...


I DO!.....if I'm stuck working with them and have to always wait for them as they tinker, then have to hold a piece a certain way, put more weight on my left leg, tilt my head 63* when I cut to make it come out square. lol!

But like I said, some guys are tinkerers and some aren't. I also know better than to ask an engineer a simple question......if I don't have 15 minutes to listen to the answer. Every person is their own.


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## Tom Struble (Mar 2, 2007)

then bring your own tools:thumbup:...next:clap:


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## CO762 (Feb 22, 2010)

Tom Struble said:


> then bring your own tools


Actually, I wound up doing that more and more. Then I started realizing most of the people would be using my tools. Finally, everyone (including the people I was working for) would be relying on me bringing my "good tools".

So one day I stopped. Weird how everything crashed. Work slowed WAAAAAY down because no one had what was needed and of course, cuts made were ****, no one had the tools to mark things right/easy/fast, etc. I did this on a few different jobs I worked on with different people.

I've learned a lot over the years--how to do things right, how people do things, and also, how _not_ to do things.

The wise person is not only a worker, but also a big picture observer.

:smile:


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## TBFGhost (Oct 9, 2008)

CO762 said:


> I DO!.....if I'm stuck working with them and have to always wait for them as they tinker, then have to hold a piece a certain way, put more weight on my left leg, tilt my head 63* when I cut to make it come out square. lol!
> 
> But like I said, some guys are tinkerers and some aren't. I also know better than to ask an engineer a simple question......if I don't have 15 minutes to listen to the answer. Every person is their own.


 
right....b/c replacing worn bearings on a miter saw causes you to have to do those things.  My tools come out better then from the factory when I repair them....I use at least OEM grade parts but always look for higher end parts....

Bring your own tools if your working with hacks and don't let the hacks use them. Its not my fault the guys you work with can't fix their tools correctly, but I can....I now not only repair my tools, but repair the tools for the company I work for and the employees of that company.

So if replacing a bearing costs you $500 in parts and labor, then go ahead and buy a new tool, but I can spend under $15 in parts and about a half-hour to an hour of my time.


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## CO762 (Feb 22, 2010)

TBFGhost said:


> right....b/c replacing worn bearings on a miter saw causes you to have to do those things.  My tools come out better then from the factory when I repair them...


This is starting to remind me of why I don't like reloaders much. They will spend hours debating how the 270win is better/worse than the 280 rem and break out reams of handload and factory data.
Give me a 270 and I'll kill a deer. Give me a 280 and I'll kill the same deer. Then I'll go and do something else or look for another deer to shoot. Or maybe fish.

I use tools, I don't fix them. I make money by making things, not fixing my tools or those of others. If break a tool, I'll get another one and get back to work. Taking the time to take the tool to the shop, tear it down, find out what's wrong, get the necessary parts, put it back together, then go back to the jobsite is a waste of time for me. 

One can get a new DW chop box for $400. Figure all the above fix logistics to cost me a 1/2 a day of production (not counting on the time to post here for directions on how to do it  ). But what about if there are others using the same chop box? And laborers with nothing to hump/clean? And/or if we're on a tight schedule? IMO, 4 bills is nothing to plug and keep playing. 

Someone in BFE would be better off just getting another saw and getting back to work rather than asking others on the internet how to fix it, then figuring how how to fix it himself. Maybe there's not that much work up there so this down time is nothing? I dunno, so I just posted my opinion.



> I now not only repair my tools, but repair the tools for the company I work for and the employees of that company.


Sounds like that's what you like to do and I'm sure you do a very good job at it. To each his own.


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## Tom Struble (Mar 2, 2007)

thats what we were saying:thumbup:


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## TBFGhost (Oct 9, 2008)

CO762 said:


> T
> 
> Sounds like that's what you like to do and I'm sure you do a very good job at it. To each his own.


Its a fast and simple to fix many tools, when I fix tools for the company, I get paid for it. When I fix tools for fellow employees, I usally get lunch and gratitude.

All tools are built in a plant using mass production which means they are highly modular. Being modular allows one to just get a new part, pull off the old one and place it on there and be done. Its not the big deal you make out to be nine times out of ten...and when I can't fix it easy or cheap, out to the trash it goes. 

I agree that tools are ment to used and use them I do, I just also happen to know how to quickly troubleshoot many tools and have them repaired for many times less what it would cost to replace the tool.

The past few bearing fixes....

DW706 which had armature bearings that were drying out, guy stopped using it proir to damage. I replaced the rear one which cost $2 plus shipping and just pulled the seal off the front one and re-lubed it. Total time, including the amount spent ordering the parts...under 1 hour. So I saved the guy $294, and if I charged him $50 a hour to repair it, I still saved him $244.

I also just fixed another(not my own) Hitachi C10FS. Cost $12 in parts, and 1 1/2 hours to fix. A new C10FSH costs around $550. I saved the company over $500

The last of the three was a DW744 table saw...bad bearing. $5 in parts, 1 hour labor. Again saved the owner $395.....

I personal Hitachi C10FS, I bought with bad bearings and no brushed and a few other mic things. $50 in parts, 2 hours labor and $20 for the saw it self.... 

I repaired the rear armature bearing in my Bosch 4100 table saw...but I let that one siezed up first....so it took the motor housing with it. Bosch service center wanted to reaplace every part in the motor for a total cost of over $300. I bought new brushs, a motor housing and a bearing for a total around $60, spent 1/2 installing...

I replace both wearing brearings in my Bosch colt router...$20 in parts, 1 hour labor.


All the bearings I use are sealed bearings with higher ABEC ratings then the factory bearings...the tools run smoother and quieter most of the time. I also noticed my Colt router doesn't get as hot down where you hold it.


If you don't know to difference between a wrench and socket, then maybe fixing isn't for you...but if you want to learn so you can add another skill to your "tool belt" then by all means learn. Knowledge is power...I used to be an autobody tech and I find myself using things I learned over there here in the carpentry world.


Oh...like this little side effect from all this expericane with bearings...It was a sunday and the idler pully on my truck starting to squeek....I didn't want to buy a cheap part from Advance and my normal store was closed....so I pulled the pully, cleaned it up, found the bearing is just a standard roller bearing with rubber seals. Pulled the seals, cleaned it out, lubed it up, installed the seals and put it back on. 45 min. later I had a quiet truck again...that was about one month ago..its still quiet....


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## CO762 (Feb 22, 2010)

TBFGhost said:


> I used to be an autobody tech and I find myself using things I learned over there here in the carpentry world.


*THAT'S IT!* Now I know why you suffer from the affliction you have--YOU _*LIKE*_ TO DO IT!!!!! :laughing:

I AB-SO-LUTELY hate working on vehicles and electronics even moreso.
I swapped out an engine in a vehicle in the street in front of my house one time. After that, people were coming up to me asking for advice on what's wrong with their vehicle, wanting me to work on theirs, etc. 
I laughed and told them the only reason I did that was because I didn't have the money to have someone else do it. :laughing:

I also intellectualize the problem. A chop box costs 4 bills. I've used that box for, let's say four years. I've made enough money off of that initial $400 investment that I can give it away or even 'sell' it, buy a new one, and be waaaaaay out ahead. 

There are people that take old tools and refurb them, then use them or sell them. There are stores that do that with appliances. There's not a whole lot to a vacuum or a dryer, but I still toss them out and buy new ones when they go poof! I'd just as soon build something, drink a beer and watch football, go fishing, cruise the internet, etc.




> It was a sunday and the idler pully on my truck starting to squeek...so I pulled the pully, cleaned it up, found the bearing...Pulled the seals, cleaned it out, lubed it up, installed the seals and put it back on.


There is something seriously wrong with you.  :laughing: I'da given it a few more months, then did a quick swap out, and continue my way to fish or what have you. :thumbup: I value fishing higher than not tolerating a squeak. I'll turn my radio up for that one...... 

Speaking of which, off to go fishin! :thumbsup:


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## Tom Struble (Mar 2, 2007)

This guy is crazy:stupid::clap:


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## CO762 (Feb 22, 2010)

Tom Struble said:


> This guy is crazy:stupid::clap:


TBFGhost is the one I'm starting to question. 
He clearly undervalues the value of fishing....


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## TBFGhost (Oct 9, 2008)

CO762 said:


> *There is something seriously wrong with you.  :laughing: I'da given it a few more months, then did a quick swap out, and continue my way to fish or what have you. :thumbup: I value fishing higher than not tolerating a squeak. I'll turn my radio up for that one......
> 
> Speaking of which, off to go fishin! :thumbsup:*


*

The time it took me to clean and relube that pully took less time then putting in a new one b/c I didn't have to drive to the store to get one. 

I don't like my cars/trucks to squeak...one a funny noise is the first indication something is going wrong...fix it now while its easy and not stranded someplace. Two even the nicest kept truck will look like a POS if it sqeaks or has exhaust leaks.*


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## TBFGhost (Oct 9, 2008)

CO762 said:


> TBFGhost is the one I'm starting to question.
> He clearly undervalues the value of fishing....




I find fishing boring...paintball on the other hand....


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## CO762 (Feb 22, 2010)

TBFGhost said:


> I find fishing boring...paintball on the other hand....


Maybe you need to try a different lure?


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## Railman (Jan 19, 2008)

[/QUOTE]
That looks just like the two our cat brought home to our deck last night!
Joe


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## Dirtywhiteboy (Oct 15, 2010)

CO762 said:


> Maybe you need to try a different lure?


Cat Fishing:clap: I Love CatFishing:clap:


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## CO762 (Feb 22, 2010)

Dirtywhiteboy said:


> Cat Fishing:clap: I Love CatFishing:clap:


 Got two channel cats the other day, nice eating size--about 18 inches.

We kill time catching cats or anything else until the musky/northern decide they want to come out and play.


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