Unisaw bearings going out!

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Forum topic by Imakenicefirewood posted 07-29-2016 04:49 AM 1779 views 1 time favorited 17 replies Add to Favorites Watch
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77 posts in 1555 days

07-29-2016 04:49 AM

Topic tags/keywords: unisaw bearings

I was given an old unisaw and recently ran new power to my garage to run it. The saw has sat for a while, and so I replaced the belts, but was hoping to be able to avoid replacing the bearings. No such luck. They really started talking to me tonight.

So my question is where is the best place to buy them? It is a 1953 (pretty sure) with the old 1 horse bullet motor.

I’m in the middle of building a cabinet for the wife’s classroom and school starts soon. So any help will be greatly appreciated.

On a side note this is what I’m stepping up from.

17 replies so far

View MrUnix's profile


7041 posts in 2398 days

#1 posted 07-29-2016 04:56 AM

Accurate Bearing


PS: Hard to tell by the picture, but if that serial number is 103-7099, it was built in 1952… if that is a 108 instead, then you are correct, 1953.

-- Brad in FL - In Dog I trust... everything else is questionable

View Gentile's profile


314 posts in 2017 days

#2 posted 07-29-2016 03:22 PM

There’s a lot of information here too…

Cool saw! Very much worth rebuilding it

-- "I cut it twice and it's still too short"

View Imakenicefirewood's profile


77 posts in 1555 days

#3 posted 07-29-2016 03:52 PM

Thanks for the input. And I agree…it is a cool saw.

It is 103, so you are right it’s from 1952. I got the saw from my father-in-law a few years ago, and he bought it at a school auction in 1992. So as far as I can tell, I’m the third owner of a 64 year old saw. It’s kind of neat working on a saw that is double my age.

I called Accurate Bearing, but will have to get the part numbers off of my bearings first. I guess I know my Friday night plans. I think I should replace the motor bearings as well. What do you think?

View bigblockyeti's profile


5285 posts in 1919 days

#4 posted 07-29-2016 03:58 PM

If you’re already tearing it apart and don’t mind doing the motor too (a good idea just for cleaning) than by all means do them too, the saw will be ready for another 64 years!

-- "Lack of effort will result in failure with amazing predictability" - Me

View TheFridge's profile


10705 posts in 1685 days

#5 posted 07-29-2016 04:08 PM

I’d do it.

-- Shooting down the walls of heartache. Bang bang. I am. The warrior.

View runswithscissors's profile


2892 posts in 2224 days

#6 posted 07-30-2016 07:44 AM

I’d pull the bearings and take them in to the bearing shop (assuming you have one within reach).

I found the easiest way to work on the bearings was to tilt the saw. Propped the edge up on a 4 X 4, which gave about the right height and angle. Sit on a low stool. If you’re concerned about it going too far, clamp a stick on the far side to brace it. Way easier than scrunching down or crawling inside the saw. Of course, if you were to remove the top . . .

-- I admit to being an adrenaline junky; fortunately, I'm very easily frightened

View MrUnix's profile


7041 posts in 2398 days

#7 posted 07-30-2016 08:08 AM

I would replace both arbor and motor bearings since you will already have things apart. If one bearing has gone toasty, the others shouldn’t be too far behind. And pull the top – 4 bolts and it comes right off; makes it really easy to get to things so you can pull the arbor off. Tip: mark the location of the table before removal so it’s easier to get it back to where it was. A straight edge along the blade and a couple pieces of masking tape work well. If unsure, take lots of pictures along the way.

And yes, yank the bearings first before ordering so you can verify what you have. Older Unisaws used 88503 bearings (extended inner race) in the arbor, while newer ones use more common 6203’s. For the motor; lots of different motors were used in those machines, so you really need to open yours up to figure out what it has as well.


-- Brad in FL - In Dog I trust... everything else is questionable

View Imakenicefirewood's profile


77 posts in 1555 days

#8 posted 07-30-2016 03:55 PM

You guys are great. These are good tips to help me get it back together.

I taped two pieces of paper to the top and marked the blade alignment as suggested, and then pulled the top off and exposed the inner workings.

I took a lot of pictures of how things were lined up and put all of the parts in little sandwich baggies that I labeled so I don’t forget what went where.

I think the set screw had vibrated a little lose.

Also, those bullet motors are heavy. I left all of the wiring connected, and just sat it on that little platform. That’s where I took it apart.

I got one of the four bearings off last night, but I don’t own a gear puller, so I borrowed one this morning. I will contact a couple of places early next week about getting new ones before I forget how to put everything back together.

Quick question: What is the best way to clean out the inside of the motor? I was just going to gently wipe out the carbon from the housing, and blast the rest with compressed air. Is there a better way?

View bigblockyeti's profile


5285 posts in 1919 days

#9 posted 07-30-2016 06:48 PM

Compressed air should work for every part of the motor. For particularly obstinate dirt and dust an old toothbrush usually works great. I would be sure to blow the carbon from the commutator and inside of the motor while outside and upwind!

-- "Lack of effort will result in failure with amazing predictability" - Me

View MrRon's profile


5192 posts in 3442 days

#10 posted 07-31-2016 07:47 PM

One thing to keep in mind. Bearings come in different grades, from general purpose to precision. Precision bearings cost a LOT so be aware of what your wallet can afford. At the least, you want bearings that are double sealed and have dust shields. Being it is a unisaw, I would go with the best bearings I could afford, at least for the arbor. Motor bearings can be general purpose It’s the arbor where the most accuracy needs to be (little to no runout).

View Imakenicefirewood's profile


77 posts in 1555 days

#11 posted 08-03-2016 09:36 PM

I tried to get the bearings from Whitten Supply in OKC, but they weren’t able to get the right ones for a decent price. They could get the motor bearings but they were really expensive, and couldn’t get the arbor bearings, so I ended up ordering from Accurate Bearing as Brad suggested. Hopefully they will be in soon.

I cleaned and lubed all of the gear teeth and areas where there is metal on metal movement with paste wax.

Now I wait.

View Lee's profile


126 posts in 1077 days

#12 posted 08-03-2016 11:28 PM

That’s a cool old saw, one other thing, you probably don’t have a bearing heater, so you will have to drive the new bearings on, use a short piece of pipe just big enough to fit over the shaft and make contact with the inner race, under no circumstances hit the outer race or the dust seals. also I’ve used a very lite film of machine oil on the shaft to help the bearing slide on, to reduce metal dragging. hope this helps, Lee

-- Colombia Custom Woodworking

View Imakenicefirewood's profile


77 posts in 1555 days

#13 posted 08-03-2016 11:50 PM

I agree…it is a pretty cool old saw.

You are correct in your assumption about the bearing heater. Thanks for the good information. I will have to find a piece of pipe the right size.

View unbob's profile


810 posts in 2102 days

#14 posted 08-04-2016 12:16 AM

The bearings are a common size, good grade electric motor bearings are what was used. I highly recommend Accurate bearing for replacements, they will have a selection to choose from, and will give you the best options and price anywhere.
If you have a 100wat light bulb, that is an effective bearing heater. Usually when the bearings are warmed up “under 200f”, the parts will slide together without needing a press.

View Clarkie's profile


466 posts in 2040 days

#15 posted 08-04-2016 01:13 AM

Have you turned the motor on since you found the keystock loose because of the missing setscrew? See if the motor makes noise now, just a thought. Many years ago a friend of mine swore he needed bearings for a drill press he had, it was making one heck of a racket when running. I looked the drill over and saw that the keystock had slid out of place, I returned it and tightened the setscrew and the motor purred instead of screaming. You may have a simple fix.

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