3HP Motor Tear-Down Clean-up and Bearing Replacement #3: Re-assembly Time! New Bearings Installation-3HP 1Phase PM 66 Motor

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Blog entry by RichmanNot posted 02-01-2017 05:39 AM 2350 reads 0 times favorited 5 comments Add to Favorites Watch
« Part 2: Clean-up Time and Painting Time! Part 3 of 3HP Motor Tear-Down Clean-up and Bearing Replacement series no next part

First off thanks to all who have read and followed along on the tear-down and re-furbish of my Powermatic 66 10-inch Cabinet Saw. I Have enjoyed sharing the process by way of the BLOG entries here on Please feel free to use this for your own information, and please share with anyone who may have need of this type of information. I welcome your comments and any corrections, no one is perfect – the last perfect person was crucified over 2000 years ago.

OK between yesterday and today I found enough energy and time to finish up the Marathon 3HP motor that will be the workhorse of my BARN-FIND Powermatic 66 I brought home on New Years Day 2017.

I began to reassemble the motor in the reverse order (for the most part) of the way it was torn-down. Now that everything was all clean and painted it was a enjoyable bit of work to get it back together.

To begin the process, I took the rear casting (or bell as some call-it), and began by re-installing the “WAVY WASHER”

(The photos here were taken earlier prior to the painting I did- in case you wondered)

NOTE: The Wavy washer installs under the rear casting ball bearing. I took one more look at the old bearing to compare the two and verify the numbers on each were the same number.

Once the wavy washer is in the “well” the rear bearing is laid into the well, and held in place by that flat head #8-32 screw. The bearing in the rear ‘bell’ is not a pressed in bearing.

One thing I did and like to do, is to take all the screws and small parts and do a ‘sort-out’ and pre-install just to check and to make sure I know where each part goes That is why you see these screws in the bell here.

With the rear bearing installed and held down by the flat head screw, the next thing is to position the bell close the the motor housing so the contactor can be attached to the rear casting. From here we are going to be
re-attaching the CONTACTOR and the RESET DEVICE.

The contacts had been cleaned earlier by way of emery paper and should be in good shape for many years to come.

NOTE: During Disassembly, I drew an arrow on the contact pad. The arrow points up towards where the opening is for the reset device. Taking lots of pictures helped in a big way!

The next thing was to re-mount the reset device into the rear bell. There are a couple of long brass screws, two spacers and two nuts. Here I am lining up the spacers to the screws. I used the needle nose vice grips to install the spacers and the nuts from the the top of the opening

Now that the components are all installed in the rear casting bell, you can align the bell up to the rear motor housing. The fit is a snug friction fit. You also need to take two of the LONG ‘case bolts’ and get them lined up. This is a bit tricky but with patience you will get the two bolts inserted all the way down to the other end of the housing. If you had marked these two parts earlier that would help get things lined up so the bell is in the right rotation on the housing. I used my photos and the fact that the reset button opening was in a parallel position to the J-box.

Once the two LONG bolts are down in the housing, and you are sure of the correct rotation of the bell to the motor housing, go ahead and “seat” the casting bell. I used a plastic coated dead-blow hammer to ease the casting to its seated spot.

OKAY! Great job! Now the fun part! LOL

Moving up to the front end of the motor we are going to install the front bearing onto the rotor shaft and button up the remaining parts.

Being a bit redundant… But go ahead and verify the bearing!

(Some bearings look different from one face to the other—- If you run into this, a rule of thumb is to install the bearing on to the shaft with the Brand Name and Numbers towards the pulley.) In my case the bearings were the same on both faces – so it did not matter which way they are installed.

With the rotor on a good clean surface, I put a rag under the rear end of the rotor and proceeded to install the front bearing onto the rotor shaft.

WELL.. It was time for coffee…. So I put the rotor into the CHEST FREEZER for about 20 minutes!

Some guys will put the bearing in an oven for a few minutes at about 200 degrees or you will read they use a “hot-oil bath” and so forth. With these being a sealed bearing, I elected to just cool (to “shrink’) the rotor shaft a tad bit.

To install the front sealed bearing, I elected also to use the old bearing to act as the “press” to drive the new bearing on. There are several methods out there to install bearings, from using “a type of press” to using all manner of pipes and other sleeve type devices to get the bearing seated.

In my case I will use the old bearing a piece of 1 inch PVC pipe and my orange dead blow hammer.

OK! take note—In order to use the old bearing I needed to file out the inside of the old bearing a little bit so it did not get “STUCK ON” with the NEW BEARING!

I did that by using a small sanding roll and my drill to take a few thousands off of the old race – so it would not end up being stuck on the shaft once I seated the new bearing.


That ring goes on behind the bearing and in front of the fan blade. It is what holds the front Casting Bell to the rotor shaft!

Once I was ready, I slid the new bearing onto the rotor shaft along with the old bearing, and using the PVC pipe and dead blow hammer proceeded to drive the bearing on. Just make sure you had it started straight to begin with!

I had some pictures showing the “seated” bearing, but they are too hard to really see what I am going to tell you.

The picture above shows the bearing NOT THERE YET!

What you need to do is get the bearing driven on all the way down to the “shoulder” of the rotor shaft. You may have to stand the rotor up on end on a piece of soft wood either on the table or as I did I stood it on a block of wood inside the vice and finished driving the bearing on with the old bearing and the PVC pipe.

(Whatever you do, all of the driving force should be against the inner part of the old bearing)

Once the new bearing is seated all the way onto the rotor shaft, it is time to attach the front casting bell.

In order to get the Bell connected to the RING, take two of the LONG BOLTS (case bolts) and use them to thread into the RING. Once you have snagged the RING pull in on the long bolts and line up the Bell.

Once the RING is “sucked -up” against the Bell, hold one LONG BOLT and unscrew the other one. Replacing the one you unscrew with the correct bolt. Then semi-tighten it, and then remove the other LONG BOLT and replace it with the correct bolt and tighten them down snug.

Now the front bell is assembled and ready and the rotor assembly can be re-inserted into the motor

Once again alignment is the KEY! In my case, I looked back at my pictures, and I saw that the two screws used to hold the casting and ring ‘lined up’ in a HORIZONTAL plain to the J-Box and that there is an OIL plug on the left at 10 O’clock position. However your “marked” casting to housing may be different – the correct rotation may or may not be critical – I choose to think it may be?

With the front casting (bell) and rotor in your hands slide the rotor assembly ’gently’ into the windings and motor housing. Slowly “guiding” the assembly all the way in until the rear of the shaft begins to protrude out of the rear casting bell.

Once you are close to it being all the way in, line-up the front casting bell by getting a long bolt started into the tapped hole in the bell, and get one of the LONG BOLTS started by hand from the rear bell.

Make sure you just use your fingers to get the LONG BOLTS started into the front bell. Get all four of the LONG BOLTS started into the thread of the front bell before using a wrench. In my case I used a nut driver once I was sure I had all 4 started straight with out any cross-threading going on.

Snug up all four LONG BOLTS with a nut driver or small socket. IF needed use the dead blow hammer to help ‘seat’ the bell to the motor housing. DO NOT GO CRAZY AND OVER-TIGHTEN THOSE 4 LONG BOLTS! Just make them ‘snug’.

OK…. Congrats! “MAJOR PROGRESS!”
Next steps are installing the V-Belt Pulley, the Rear Fan, the J-Box Cover and the REAR Fan Cover! Heading to the home stretch!

Reinstalling the V-Belt Pulley onto the Shaft…
Now remember when I used a pencil to measure the depth of the V-pulley? I put a piece of tape at the cut mark so I could see it better. Then I grabbed the square key stock… But OH OH! There are a couple of burrs on the key. So I filed down the burrs before inserting the key into the key way.

Just make sure the key is going to be positioned for the Allen Screws. (if you slide it too far back it will have a tendency to “rise up” – because the key-way slot tends to taper upwards at the back end (just the way most end up due to milling work) Look at it from the side, it should look even in height above the slot on the shaft.

Slide the Pulley on it should go on fairly easy. That is why you ‘polished’ the shaft with emery paper!

There are 2 set screws – which will need to be tightened down good once the depth of the pulley is set!

Using the pencil as my guide I set the depth of where the pulley was when I took it off for the tear-down.

Next I turned my attention to the J-Box.
Recalling how much saw-dust was inside the J-Box I decided to use some weather stripping around the perimeter of the cover.

Then using a ice-pick to get the screws through the weather stripping I attached the cover with its 4 screws.

The small aluminium cover plate over the access hole for the reset button was installed… But I made a new ‘gasket’ for it first using a thin piece of cardboard using the old damaged gasket as a pattern. The ice pick and a drill were used to make the holes for the 2 retaining screws.

The fan on the rear of the shaft is next…

Again, a small set screw holds the fan onto the shaft

Success! We are at the end of the motor rebuild!

With the fan on the near final piece is the rear ‘fan shroud’ (or cover). I started out painting it black. But the 1st time I sprayed it I had “runs” so I sanded again, and the runs still showed through! So the 3rd time I decided to use primer first. Then I thought the Hammered Grey “Cast Bells’ looked so cool on the ends of the motor housing, I decide to paint the Fan Shroud Hammered Grey too!

SO THERE WE HAVE IT! I think it looks better than NEW? What do you think?

(sorry… I did not get the final photo in time to post it. I think I will add it as a comment?)

-- "can't died in the poor house" (Because he always went around saying... "I can't")

5 comments so far

View Rich's profile


5126 posts in 1190 days

#1 posted 02-01-2017 05:56 AM

Again, great detail. I love this series. That’s going to be one beautiful saw.

-- Half of what we read or hear about finishing is right. We just don’t know which half! — Bob Flexner

View RichmanNot's profile


39 posts in 1111 days

#2 posted 02-01-2017 05:58 AM

Thanks Rich Taylor——Rich P

Again, great detail. I love this series. That s going to be one beautiful saw.

- RichTaylor

-- "can't died in the poor house" (Because he always went around saying... "I can't")

View Redoak49's profile


4340 posts in 2589 days

#3 posted 02-01-2017 12:01 PM

An excellent blog with great pictures and comments and also easy to read.

View Kaleb the Swede's profile

Kaleb the Swede

1915 posts in 2570 days

#4 posted 02-01-2017 07:38 PM

Vet cool blog. I am enjoying this immensely. One day I hope to o a machine restore myself

-- Just trying to build something beautiful

View RichmanNot's profile


39 posts in 1111 days

#5 posted 02-02-2017 06:14 AM

Thanks for the nice comments! Here is the before and after shot and a couple of pictures of the completed assembly.

Again, great detail. I love this series. That s going to be one beautiful saw.

- RichTaylor

-- "can't died in the poor house" (Because he always went around saying... "I can't")

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