Help with Saw Bearings

[Bruce Wrenn]

Does anyone know how important it is to use a bearing heater during reassembly when replacing bearings? I have not used one. I have read and been told that to do the job properly a bearing heater is required. I have done several replacements that did not last nearly as long as OEM. I also see bearings with the same size numbers in price ranges from $10 to $100 dollars.

Today's bearings are much better than they used to be. Price doesn't always translate to quality. As an example, on daughter's Honda Civic tensioner bearing failed. Replaced it with a $17 bearing from NAPA, which lasted less than six months. Replaced that bearing with a $1.99 bearing from Fastenal, which now has over 300K miles on it. FYI, bearing is a 6203 2RS, same as in saw. The 6203 is probably the most common bearing in usage in the world.

[Maurice Mcmurry]

I put front wheel bearings in our Toyota 3 times. The third time the parts counter guy insisted that I check out the torque wrench as well as the axle puller and front wheel drive bearing press kit.

[Gustav Gabor]

I've found that heating bearings, along with cooling the arbor shaft has worked really well for me so far, particularly on bearings larger than 1 1/2" od.
I cool the arbor shaft in a freezer for at least 2 hours, and heat a socket that is just a few hundredths smaller than the inside diameter of the bearing to about 350 - 400 degrees F.
With welders gloves or vise grips, I place the very hot socket into the bearing to transfer the heat and expand just the inner race of the bearing. I check with a digital temperature gauge, and once the inner bearing race is up to about 250 degrees, I take the shaft out of the freezer, quickly wipe the condensation off the area the bearing will mount to, remove the socket from the bearing, and immediately drop/place the bearing onto the shaft.
It's a one shot deal, and has to be done really quickly, otherwise the bearing will shrink onto the shaft before it gets to the final position.

I find that by heating just the inner race, the bearing grease isn't overheated as it would be if heating the entire bearing in an oven.
A proper bearing heater would of course be the way to go, but as I have yet to win the lottery, not happening anytime soon ....

[Maurice Mcmurry]

The guy who told me about the benefits of using a heater has experience with routers. He has several old ones that he keeps going. His heating technique is much like Gustav's

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[Robert Engel]

I'll have to look further into this thanks... the biggest headache I can see is how to get the arbor mount out to even be able to change the bearings... really don't want to take the top off the table that can be a real pain to get back straight... so it goes

Hey, Kurt I had this saw (2001) and have been through the procedure. The set screws on my pulleys were loose, too and I think this caused the bearings to go bad. But they lasted 21 years.

You have no choice you have to take the top off in order to get to the arbor bracket set screw. Over on the NCWoodworker's site one knowledgeable guy said replace the allen screw with a bolt. This enables you access it with the top on which helps in realigning the arbor bracket. I HIGHLY recommend you do this, as it will enable you to realign the arbor with your zero clearance throat plates after the top is on and the miter slots aligned.
IMG_0476.jpg

The huge mistake I made was not realizing the retaining nut (opposite end of arbor) is left hand thread - don't forget this! I ended up stripping it with an impact & luckily I had a friend weld up, rethread it and get a new nut.

To get the arbor assembly out, you have to loosen the retaining screw and work the arbor bracket parallel to the height adjustment threads with a little wiggling it will come loose.

The bearings came out and installed very easily on mine. Good luck getting the table on and off and realigned was the hardest part. I purchased the bearings from Jet, but there are replacements I'm sure just as good. Maybe not necessary, but I also replaced the wave washers.

[Kurt Wyberanec]

Hey, Kurt I had this saw (2001) and have been through the procedure. The set screws on my pulleys were loose, too and I think this caused the bearings to go bad. But they lasted 21 years.

You have no choice you have to take the top off in order to get to the arbor bracket set screw. Over on the NCWoodworker's site one knowledgeable guy said replace the allen screw with a bolt. This enables you access it with the top on which helps in realigning the arbor bracket. I HIGHLY recommend you do this, as it will enable you to realign the arbor with your zero clearance throat plates after the top is on and the miter slots aligned.
IMG_0476.jpg

The huge mistake I made was not realizing the retaining nut (opposite end of arbor) is left hand thread - don't forget this! I ended up stripping it with an impact & luckily I had a friend weld up, rethread it and get a new nut.

To get the arbor assembly out, you have to loosen the retaining screw and work the arbor bracket parallel to the height adjustment threads with a little wiggling it will come loose.

The bearings came out and installed very easily on mine. Good luck getting the table on and off and realigned was the hardest part. I purchased the bearings from Jet, but there are replacements I'm sure just as good. Maybe not necessary, but I also replaced the wave washers.

Hi Robert, I'm very confused....I had no idea that nut was left hand and that is in fact the nut that I snugged just a tiny bit, but righty and the noise improved! I only moved the tiniest amount which made me think I snugged it, did I actually loosen it?

The though of getting that table aligned back really bothers me....do you think it is at all possible to get it off without removing the table? And did you remove the bearings yourself or have someone do it? Also, did you replace the load springs and anything else that's in that assembly?

Thanks!

[Bill Dufour]

Classic bearing heater trick is to set it on top of an incandescent light bulb. Or use a skillet of hot oil. For wood shop size bearing should never need to heat or cool. maybe planer main cutterhead bearings.
Dry ice is cheap so is a CO2 extinguisher or paint ball tank. Liquid N is too cold and risks cracking the metal.
Just be carful that it is a straight push no lever action that will break a casting arm off.
Bill D.

[Mike Monroe]

My funny bearing story has to do wiht my old 1997 F-150. A front wheel bearing was going out but I couldn't tell which one. I had a mechanic ride with me and he said it was the right front. So I ordered a new front wheel and installed it on the right front. Noise is still there in the front end, so I take the wheel bearing I just took off the right front and put it on the front left. Noise gone. After getting the left front bearing off it was plain to see that the wheel bearing was bad. Drove that truck for 298, 854 miles. The only thing I replaced on it were tires, brakes, a headlight bulb, plugs, the alternator, a wheel bearing, and two batteries (the OEM battery lasted 11 years).

Oh and I've replaced the bearings on my Delta Unisaw after 20 or so years of use.

[Jerry Bruette]

Hi Robert, I'm very confused....I had no idea that nut was left hand and that is in fact the nut that I snugged just a tiny bit, but righty and the noise improved! I only moved the tiniest amount which made me think I snugged it, did I actually loosen it?

The though of getting that table aligned back really bothers me....do you think it is at all possible to get it off without removing the table? And did you remove the bearings yourself or have someone do it? Also, did you replace the load springs and anything else that's in that assembly?
Thanks!

Maybe while you were moving the hex nut you moved the spanner nut that it's inside of and that may have made the noise go away. If the wavy washers are still wavy they should be good. The only time I've replaced one is when it's broke or got lost. I think the only reason there's wavy washers in that assembly is to take up the movement that could happen from the shaft assembly getting warm. When the shaft warms up it gets longer. The bearing on the blade end of the arbor should be held so the blade never moves and the other end would have the wavy washer to take up the thrust from the assembly warming up.