Old PM 66 teardown update:

[Charlie Woods]

Nick, my senior student working on the saw has already pulled the top off, and has the motor/motor mount removed. He asked me if he should go ahead and replace the bearings on the blade shaft. Since we don't know what kind of abuse the saw has been through I suggested we go ahead and do it, but wanted to see what you guys/gals think??
Nick is labeling/taging each nut, bolt and part, while potographing each step.( Will add photos as soon As I get them downloaded. Thanks for the suggestion).

Will try and update you on the process as I can.


Charlie

[Jim DeLaney]

<I>Nick, my senior student working on the saw has already pulled the top off, and has the motor/motor mount removed. He asked me if he should go ahead and replace the bearings on the blade shaft. Since we don't know what kind of abuse the saw has been through I suggested we go ahead and do it, but wanted to see what you guys/gals think??
Nick is labeling/taging each nut, bolt and part, while potographing each step.( Will add photos as soon As I get them downloaded. Thanks for the suggestion).

Will try and update you on the process as I can.


Charlie</I>

Charlie,
Since you've already for the saw torn down, I'd definitely replace the arbor bearings. Go to a bearing shop (NOT Powermatic) and buy a set of sealed bearings in the best grade they have available. Shouldn't cost you a lot, and will extend the life of the 'ole 66' for many, many years.

[Chris Padilla]

Charlie,

Might as well...take the old bearing to a bearing suppy house and you should be able to get an upgrade to what was originally used.

[Bob Smalser]

Murphy has a rule that says something to the effect that the first bearing/thrust washer to go south after reassembly is always the one that spec'd out good and wasn't replaced.

McGee's Corollary is that the deeper into the machine in terms of man hours that bearing is, the faster it will fail.

[Ted Shrader]

Murphy has a rule that says something to the effect that the first bearing/thrust washer to go south after reassembly is always the one that spec'd out good and wasn't replaced.

McGee's Corollary is that the deeper into the machine in terms of man hours that bearing is, the faster it will fail. ... and the less it will cost!

Charlie -

When I get that far into a machine (engine, transmission, saw, jointer, whatever...)all those kinds of things get replaced. Have even been known to change out bolts for Grade 8 steel for additional (but probably not needed) strength.

Ted

[Boyd Gathwright]

Ted, my feelings exactly and if you can’t afford it you do the best you can with what you got ;).

Boyd
.

... and the less it will cost!

Charlie -

When I get that far into a machine (engine, transmission, saw, jointer, whatever...)all those kinds of things get replaced. Have even been known to change out bolts for Grade 8 steel for additional (but probably not needed) strength.

Ted

[Charlie Woods]

I appreciate the confirmation gentleman. I don't always go with the old addage "if it ain't broke don't fix it", especially with "Murphy" waiting to strike. There are several places here iHouston and Katy where I can get bearings. I am going to try and post some photos and a diagram of the arbor I found in an older manual for the saw. I hope it works, because I am having trouble getting the arbor locking nut loose. Both Nick and myself have worked on this.

If you look at the diagram it shows the end of the shaft with what it calls wrench flats. This is supposed to hold the shaft in place with a second wrench while removing the locking nut. I have tried several times to get it loose but it will not budge.I placed an old 1x4 underneath the bearing support( see picture if it uploads), so I could put more weight onto it with out it bending to much; but it still would not budge. Now mind you at 6'3" and 276lbs I can put alot of stength behind the wrench but it still has not moved. I am afraid to put a pipe on the end of the wrench for fear of bending/breaking something. When I cannot see any ouward reason for the nut not breaking loose. Any suggestions. I have several ideas in mind but don't want to mess it up. When I rush things I have a tendancy to be able to "screw up a one man parade going through a ghost town". Thanks all of the suggestions in advance.


Charlie Woods

[Boyd Gathwright]

…. Try tapping and/or heat before putting the muscle on. What about “Loc-tite” any evidence on the threads that it was used? What about a left-hand thread :confused: .<O:p</O:p

…. Just trying to help.


Boyd
.

I appreciate the confirmation gentleman. I don't always go with the old addage "if it ain't broke don't fix it", especially with "Murphy" waiting to strike. There are several places here iHouston and Katy where I can get bearings. I am going to try and post some photos and a diagram of the arbor I found in an older manual for the saw. I hope it works, because I am having trouble getting the arbor locking nut loose. Both Nick and myself have worked on this.

If you look at the diagram it shows the end of the shaft with what it calls wrench flats. This is supposed to hold the shaft in place with a second wrench while removing the locking nut. I have tried several times to get it loose but it will not budge.I placed an old 1x4 underneath the bearing support( see picture if it uploads), so I could put more weight onto it with out it bending to much; but it still would not budge. Now mind you at 6'3" and 276lbs I can put alot of stength behind the wrench but it still has not moved. I am afraid to put a pipe on the end of the wrench for fear of bending/breaking something. When I cannot see any ouward reason for the nut not breaking loose. Any suggestions. I have several ideas in mind but don't want to mess it up. When I rush things I have a tendancy to be able to "screw up a one man parade going through a ghost town". Thanks all of the suggestions in advance.


Charlie Woods

[Jim Knauss]

Being a mechanic all my life ive leaned one thing. If it doesnt come off there is usually a good reason and do not force it. My guess is it could be left hand thread. Can't see it from picture but what I do is take my finger nail and trace the threads on the bolt, see if your finger moves in or out. Also compare with anther bolt, should be obvious. Also use a 6 point open end wrench to avoid rounding corners. You could also call PM and ask Techs,
Hope this helps,
Jim Knauss

[Norman Hitt]

Charlie, considering the direction of rotation of that shaft, I would think there is a strong possibility that it is a left handed thread on that end of the shaft. You might want to give Powermatic a call with the serial #, and check before you get too rough on it. If it is not a left handed thread and just "Stuck", you might try warming it up with a large drift pin and a hammer, or a light application of heat with a torch. If all else fails, you can use a Nut Splitter, and replace it with a new nut.

I looked in my '91 model's manual, but it doesn't have that nut in the diagram.

[Steve Evans]

Charlie

I'm with the others, from the picture it looks like a left hand thread.

Steve

[mike lucas]

My 66 isn't as old as the one you are working on. However, mine is left hand thread (reverse thread) But I am sure you have thought of that, and don't need us repeating over and over.:eek:

[Chris Padilla]

Get an impact wrench on it if you can...be sure it is on "forward" however! :D

[Charlie Woods]

It is a right handed thread. Called Pm tech support and they said the same thing. Also found a nut that would fit and it threaded on to the right. ( It would seem logical to have made it a left hand thread since the turning direction of the shaft would help keep the nut on the arbor.) We will probably apply some heat to the shaft and try and remove the nut. I am building a base that will support the arbor bearing housing completly before I do anymore turning. I will leave the impact wrench for last. We will be back at school Dec 26-31 working on our next production so hopefully we will have the saw trunion dismantled down before the New Year.
I want to thank each of you for your help to a question that some may have thought was very obvious to solve. I do not hesitate to ask a question, nor reasearch for an answer when it is needed. I teach my students the same thing, no matter what the issue. Thanks for your help and support. Will have more pics of the procees and where the saw will go in the shop once completed.

Charlie Woods

Charlie Wood

[Michael Cody]

Since you said you found another nut with the correct thread,why not just crack the nut to get it off. I usually use a die grinder, but a dremel should work to cut a slot then a nut cracker would usually crack it. As a rule once you slot them, nuts crack off pretty easily. That way you don't have to worry 'bout the threads or heating the shaft??

[Charlie Woods]

Michael:

The nut was an old one given to me from the Ag shop next door. It was from an old tractor they had, and was pretty well rounded off. It did confirm the right hand thread, so I will try to apply a little heat, then an impact wrench. If all else fails, I will see if I can find a replacement nut then cut the old one off.

Thanks

[CPeter James]

I like to use an impact wrench and a product called "PB Blaster" It is penetrating oil type product. The impact wrench and a 6 point socket will take the nut off with less damage that either brute force or heat. If you need heat, get and oxy/acc torch and a SMALL tip and heat the face of the nut until it is just hot enough to sizzle spit. Then try it. DO NOT overheat it or heat the shaft any more than is necessary. If you tilt the arbor to 45º it may help getting the impact wrench on. Also, tapping won the nut with a punch and hammer after applying the PB Blaster will work the penetrant into the threads. Patience is the answer.

My other hobby is working on very old John Deere tractors, so I have lots of experience with rusted bolts and nuts. With age come patience and with patience come success without damage!!

CPeter