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Posted on Changing Bearings on a Table Saw

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opinionated

6 posts in 2922 days


#1 posted 12-16-2009 08:31 PM

I have replaced many arbor bearings on Delta saws and there are a couple of rules that govern an installation that will last as long as the original. First and foremost is to never install bearing by pressing on an unsupported race. If you istall the bearing in the casting and then press the arbor in you have damaged that new bearing and reduced its life. Second rule is to clean very throughly the arbor and casting. The third rule is never press on the arbor uing the blade flange. Even a small arbor press can easily distort the blade mounting flange. Always press using the end of the shaft as a bearing surface. The delta saws have been designed such that the blade arbor end of the casting alows the outter race to move. This is essential to accomodate arbor shafts and spacers that vary in length a few thousandanths of an inch and for thermal expansion of the shaft as the machine runs and the bearings warm up. If the surface in which the bearing is mounted is not clean this cannot happen and bearng life will suffer. As for bearings, The Standard C-3 class 6203 bearing is more that sufficient and may be either sealed or shielded. I never work on newer delta saws but the old saws always used a shileded bearing and not sealed. I have installed both and the sealed bearing seems to work fine in both the contractor and unisaw. Bearing are available on e-bay or your local bearing supply house for about half of the price you would pay from Delta.
I ave developed several special tools for installing the bearings in Delta saws, but a reputable shop with an arbor press and bearing separators and pullers should be able to remove and install the bearings in your casting. I wold add that this is the perfect time to set your casting and arbor assembly in the milling machine and true up the arbor mounting face. I use a mounted stone in a Bridgeport mill to grind the blade mounting face to achieve a less than .001 inch runout.

Here are the basic steps to installing a set of bearings in a Unisaw or contractors saw.
Remove the arbor casting from the saw.
Remove the pulley from the arbor.
Remove the locknut from the arbor shaft.
Using a dead blow hammer or brass, bump the arbor out of the casting. Don’t loose the wave washer that is installed behind the blade end bearing.
Remove the pulley end bearing locknut. Use a screwdriver and hammer for this if you do not have a 40mm slot spanner. (who except me does)
Using a brass drift remove the pulley end beaing and discard.
Using a bearing separator and puller remove the blade end arbor bearing from the arbor shaft.
Clean all surfaces thoughly with scotchbrite or fine emery.
Install the blade end bearing on the arbor shaft using a 17 mm bearing pusher and press.
Install the pulley end bearing in the casting recess and install the locknut.
Warm up the blade end of the casting using a propane torch to about 200 degrees.
Install the wave washer in the blade end of the casting.
Install the spacer tube on the shaft.
Install the arbor shaft and bearing in the casting.
The arbor should be supported by the end of the shaft on the arbor press and a 17 mm pusher should be used on the other end to ensure the load is not being transferred to the bearing races as the arbor is pressed into the housing.
Install the shaft locknut and pulley.
Check arbor flange runout and correct if required.


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