Table Saw Alignment

The bearings on the arbor shouldn’t spin freely because they are lubricated with grease.  But, if they fail the run-out and play tests, and feel pretty rough when you turn the arbor by hand, then you should probably change them.  It’s not such a difficult task when you have the right tools.  The key is to be careful so that the new bearings will give you many years of service.

The first thing you want to do is remove the nut that’s on the pulley side of the arbor.  To do this, you’re going to have to hold the arbor still while turning the nut.  I prefer to use a jamb nut on the flange side of the arbor.  A wrench on the jamb nut and one on the pulley nut will do the trick.  However, it might not be such an easy task to find a suitable jamb nut.  On this Delta Contractor’s Saw, the arbor is threaded with a left hand Acme thread.  I managed to steal one off of my Unisaw.  You can probably buy a spare at the local Delta dealer or service provider.

The thread on the pulley side of the arbor is a right hand, so loosening the nut requires turning it to the left.

There’s a bunch of crud on this shaft and it was rather difficult to get the pulley off.  Cleaning off the crud with a wire brush will make the job easier.

The pulley is cast iron and split into two parts.  There is also a spacer between the bearing and the inner side of the pulley.

Inside the housing is a retaining ring.  It ensures that the bearing stays in place.

The retaining ring shouldn’t be on tight.  It’s OK if you don’t have a spanner wrench, mine came off by pushing it around with a screwdriver.

Packed inside was a bunch of crud and sawdust.  This is why the use of sealed bearings is important.  Regular open bearings or even shielded bearings would go bad pretty quickly.

Here is the order of assembly for the pulley side of the arbor shaft. 

For the next step, I used a common bearing puller to push the arbor shaft out of the casting.  An arbor press would work nicely too but I thought that more people would have access to a bearing puller than an arbor press.

Here’s the flange side bearing being pushed out with the shaft.  It’s pretty much coated in rust and crud. 

Between the bearing and the bearing seat in the housing is a wavy washer.  This provides tension between the bearing and the bearing seat to prevent any play.  A spacer tube fits between the flange side bearing and the pulley side bearing.

The tool of choice for removing the flange side bearing from the arbor shaft is a “Bearing Separator”.  I don’t have one so I’ve used two pieces of 1/4″ steel instead.  Shown here, I have the arbor shaft in my arbor press and I’m pressing the bearing off of the shaft. 

The next step is to remove the pulley side bearing from the casting.  To do this, you will need a piece of pipe or tubing with an inside diameter that is just slightly bigger that the outside diameter of the bearing.  This piece of PVC pipe does the trick perfectly!

Here is how the PVC pipe is going to be used.  I’ve put it inside of a bolt and nut assembly.

This assembly is going to fit over the bearing seat in the casting. 

As I tighten the bolt, the bearing is going to be pushed out of the casting and into the PVC pipe.

Here are all the arbor parts in their proper order of assembly.

While I have the arbor disassembled, I might as well face the flange.  Here I have the arbor on my lathe, clamped in a collet.  The far end is being supported by a live center (those guys at Delta were so kind to center drill the ends of the arbor!).  It would be better to turn it between centers (instead of using a collet) but I don’t have an appropriate lathe dog.  So, I’m using the collet.

Just another view of facing the flange.  I used a C6 grade carbide insert for this.  Cut like butter.

Here is the flange fresh off the lathe.  Looks fantastic!

Here’s a close-up of an arbor bearing.  Notice the number: 6203L.  You’ll need this when calling around (or surfing the web) for replacements.  These bearings are made by NTN (good quality).  I’m going to end up buying new bearings for this saw but not just yet.  I’ll demonstrate reassembly with the old bearings first.

It’s a good idea to use care when installing your new bearings.  You don’t want to cause damage that can drastically reduce their life span.  So, I have another tool for installation and it must be used right.  This step can also be done on an arbor press but this bolt will work just as well.

The washers on this bolt are sized to fit the outside diameter of the bearing.  If I were to push on the inside diameter while installing the bearing, I could cause severe damage.  Some people like to tap the bearing into place with a punch and hammer.  I think this is an easy way to drastically reduce the life of the bearing and/or gouge up the inside of the bearing seat.  Pressing is always better than tapping.  When the bearing is fully seated, replace the retaining ring and snug it up against the bearing.

To press the new bearing on the arbor shaft, a properly sized piece of tubing is needed.  This piece of 3/4″ EMT conduit is just about the right size.  It cut it just a little longer than the length of the arbor shaft.

The idea here is to place the tubing over the shaft and onto the inside diameter of the bearing.

Here’s a closeup showing how the tubing touches only the inside diameter.  If the bearing stops turning freely when you start pressing, then you are doing it wrong and can be causing damage.  Some people like to tap the end of the tubing, I prefer to press.

Here it is on the arbor press.  The bearing must be pressed all the way down to the back of the flange.

Now I’m going to use the bearing puller again to push the shaft back into the housing.  Don’t forget to replace the wavy washer and the spacer tube!  On the pulley side the spacer and two pulley halves are installed before tightening the pulley nut.  The entire process took me about two hours, including hunting down tubing and washers of the appropriate sizes. 

Questions?  Comments?  Suggestions?  Post your feedback!

Thanks,
Ed