Need to replace my bearings. Stamped with NTN 62304ZZA, powermatic part #
6060009. Anything special about these bearings? Can pick up matching
bearings from NAPA auto parts if there is nothing unique about the
powermatic bearings. Any cautions or suggestions about replacing the arbor
I'd look in your yellow pages for a bearing supplier. the cost may be
less than a car parts store, the folks there will have more knowledge
about bearings and more information to cross reference from.
automotive bearings may not have the right PRM ratings or shielding,
When I replaced the bearings in my 66 recently the local bearing
store had them in stock. Everything is a tight fit so you
will need a press or puller to do the job. With a gear puller and
some imagination the job can be done. I bought a couple of
bushings for the puller to pull the bearings back onto the arbor
with, so the force would be on the inner race of the bearing. The
arbor assembly is a snug fit in the whatever it's called that
holds it. I put the rebuilt arbor in the freezer and heated the
arbor holder with a heat gun to slip it in there. I replaced the
bearings in the motor at the same time and everything was just
under $50.00. It was about a 6 hour job for me but that's also
the motor rebuild and cleaning everything up along the way.
If you don't have a book with a parts drawing, a copy can be
downloaded from Powermatic. It will help when it's time to reasembly
the arbor. Or if you make notes that would help. DAMHIKT
John, in Minnesota
Thanks for the infor. How did you get by so cheep? My saw has 2 of the NTN
62304ZZA bearings. They sell for about $65.00 each. Have downloaded the
Powermatic 66 Owners Manual from Powermatic. Also have downloaded a parts
price list and a service manual from the "Old Wood Working Machines" web
I looked for the receipt or 1 of the old bearings but can't find
either one right now. But, I believe the bearings on my saw were
6204zz's. (it's highlighted in my Grainger catalog) A 20mm bore
instead of 17mm on yours. I can't imagine Powermatic changing
something on the 66 in the last hundred years, but maybe.
6204zz are about $10.00 each. On the recommendation of the bearing
shop I used 6204LLB's or LLU's which have a better dust seal than the
ZZ. Only a couple bucks more each. I've read somewhere that the
first 2 digits of the saws s/n indicate the year of birth. If so,
mine was born in 1981. Is yours about the same vintage?
New bearings in the saw & motor made this baby run like new.
John, in Minnesota
My bearing measurements are probably the same as yours, 20mm bore, 47mm OD
and 20.5mm width. I am guessing, but I think the 63204ZZA may have a higher
temp rated grease?? Seem to get this indication from the NTN web site.
Unsure of the age of my saw, serial # is 266845. But in the right light and
a little spit it could be 2266845. Looked at the serial number sequence key
in the Powermatic section of OWWM. Can't fit my serial number into this
scheme. What is your serial number?
See another difference. According to NTN the 6204 bearing is 14mm wide and
my bearings 63204 are 20.5mm wide. If I were to use the narrower bearings I
would have to order new spacers and spring ring etc. Have to bite the
bullet and order the more expensive bearings.
fwiw I've done the bearing replacement on two PM66's, an '88 and a '71.
Bought both as basket cases and kept the 72 because it's nicer and the top
was straight. Replacement is pretty simple and straight forward
Both machines had identical arbors, bearings, spacers and housing. Later
machines have different pully drive (3vx two belt rather than original
Bearings removed from both where marked NTN 62304ZZA and original on both I
think. Double row and plastic sealed both sides. Powermatic had them for
$44 ea. Napa and a bearing house had them for $36 when I checked a few
years back, - but - the napa part had a different seal arrangement with the
race visible on one side although it was a double row 62304. So check it
In the end, for both machines I bought the PM bearings at the same time as
a few other parts needed.
I don't know about others experience but in mine I'd say this; If not using
original spec bearings still use the correct width, full size double row
bearing, It's important in both fitting straight, locating the spindle and
I think, to provide the necessary support and accuracy while running.
The bearing fit was *tight* so I think some kind of press is needed. I
first tried putting it together on the cheap with a few tubes and a mallet.
It went together with some effort, with difficulty getting it aligned
straight and in the end also ran with some runout. No explaination why but
it wasn't right.
Next try I used a cheap HF hydralic press to mount the bearings on the
spindle and it aligned and installed fine. More importantly with no runout.
Note according to powermatic the bearings are pressed on the arbor first
and then the spindle, bearing, spacer assembly pressed into the housing.
That means that one bearing is pressed into the housing by it's center
rather than, more correctly, by the outer race. You can knock the assembly
in with a mallet but its kinder to the bearing to press it I think.
Next time around on the second machine it took about an hour to remove old
bearings, fit new and replace, way longer to strip and replace the
trunnion. You could do it with trunnion in place but I had to clean it up
and replace some of the collars anyways.
My saw has 3vx pulleys. Need 3 belts or get by with 2?
62304ZZA ? or 63204ZZA? NTN does not show a 62304 and does not show a
63204ZZA. The do show a 63204ZZ/2A. Their listing shows the bearing as a
"Single Row Deep Grove" bearing with steel shields on each side (ZZ). I
assume the "A" referred to the bearings grease. "2A is shell Alvania #2.
Must be high speed grease. No one had the bearings, or equivelant, in stock
so I ordered from PowerMatic.
My arbor assembly came out real easily. Just some light tapping. Hope the
new bearings will go in as easily. Have allready dis-assembled, cleaned and
re-assembled the trunion so will try the Hot - Cold technique to ease the
installation of the arbor assembly.
AFAIK older pm66 saws had three belt pully drives, newer model (eighty
something on) had the 3VX system which confusingly is a two belt system.
If it's 3VX the pullys are two groove only.
I ran my 'old' saw as three belt and then upgraded to two belt when I
replaced the motor, the new motor had a 5/8th arbor, the old 3ph motor I
was replacing was a 3/4" and no 5/8th three belt pullys were available at
a reasonable price. new 5hp motor and 3vx belt is very smooth and I've
not had to adjust it since installing.
Hum, I've dug out the old bearings in the box of spare PM66 parts, never
threw them out. Im pretty sure that under the rust they 62304 ZZA, maybe
one of the Z's is a 2, but they definitely are two row plastic sealed
bearings approx 47m od, 20.5mm deep, 20mm bore.
If the assembly came out easily then I think you'll have great sucess
reassembling with a bit of heat/cold and some light persuasion. I had to
put some effort into it because my assebly, carrier fit was incredibly
A trick to watch when putting the assembly in is to consider the arbor
blade flange location and get it located centrally in the table slot
first, while still allowing the lock screw to locate the arbor and then
line up the motor drive pullys.
GOOD GRIEF, do you really mean you pulled them into the arbor using the ID??
That's crushing the balls and dimpling the outer race! Hopefully they
weren't very tight. Or maybe you meant "not on the inner race"? One should
never put any side load on a bearing. You could use your same rig with a
big socket pushing against the outer race, but maybe that's the bushing you
Probally was'nt too clear on that. Yup, that's when I used the
bushing resting on the inner race to pull it back "onto" the saw
arbor. Rebuilt the arbor first then slid it back into the saw. No
side force on the actual bearings was applied.
John, in Minnesota
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