Help with Powermatic trunnion

I have an old Powermatic 65 tablesaw. The trunnion has been so sweet, it would raise and lower like a feather. Suddenly now it has slop in the raising mechanism. I first noticed it when the blade jumped on start. I have torn it down as far as I can. I can see that the worm gear just has slop against the rack gear. The only adjustment I can see is on the incoming shaft with that holds the worm and goes out to the handle. I tightened up the thrust collar that pulls the worm and shaft against the trunnion, pulling the worm back as far as possible towards the front of the saw. It feels too tight npw and is hard to raise and lower, but I still have slop in the gear mating and can get about an 1/8" up\down play and see the teeth are sloppy.
It seems crazy that it could sudddenly wear out and across the entire run of tge worm and rack gear. It seems the gears need to be held tighter together but there is no adjustment to change that alignment.
Any ideas would be nice. I really want a Sawstop but don't have the cash right now, just dumped $2k in wood speculating on a new product line, now I can't start cutting. Damn Murphy ;-(
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Seriously, CALL Powermatic Tech service, no one is going to be able to advise any better than them. Otherwise, are you sure the worm gear is not sliding on the shaft that it is mounted on?
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Yes, the manufacturer is next on the list. It is just so hopeless trying to get any service from corporations nowdays I thought I would try here first. I think I really need to find the local guru but last time I did that for a machine electrician they guy was getting $100 an hour plus travel time. I did some reading and figured out how to fix it myself.
The worm is firmly on the shaft. The shaft is not moving. I can see the space in the gears and the rack gear can move a few mm, slapping against the different faces of the worm gear threads which translates into even more up\down. It is clearly gear mesh slop.
Thanks for the encouragement. I'll go down that path.

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SonomaProducts.com wrote:

I think you'll still be pleased w/ Powermatic tech support (altho it has been a few years since I last needed them, I don't think they've gone away)...
I've a Model 66 rather than 65 and can't imagine if trunnion is at all similar the symptoms you're describing being an all/nothing event, either.
There must be some cause other than wear unless this puppy is truly ancient and has seen a tremendous amount of usage over it's lifetime--maybe a nylon thrust washer failed or somesuch as a purely wag. I really can't imagine ever having enough loading on the gear/worm to actually cause them to have wear to the point of such sloppy fit.
--
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-maybe a nylon thrust washer failed or somesuch as a purely

That sounds like a good clue. I would check the dust collector or sawdust bin and see if a nylon or plastic thrust washer or stop-bumper has cracked and dropped off into the sawdust stream. That sounds like a likely senario for a sudden cause of a massive slop.
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EXT wrote:
...

Probably more productive/quicker would be to check it against what's there on parts diagram/breakdown... :)
--
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The 65 and the 66 actually share a lot of parts. The only big difference is the arbor gimbles (the curved sliding surfaces). On the 66 there is one in front of the balde and one behind. This is an improved arrangement over the 65 where they are both in front of the blade. Below the gimble they are almost identical and I have reviewed the exploded diagrams from owners manuals I got from OWWM.com. Can't seem to see anything in the diagram that is not in place on the machine.
I guess I'll I'll see if I can get a Powermatic tech on the phone or in an email conversation.

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On Tue, 9 Jun 2009 22:10:54 -0700 (PDT), "SonomaProducts.com"

You might try asking in the SHOP forum over on the OWWM site. They have a lot of Powermatic guys over there.
Mike O.
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Thx. I tried that a few weeks back when I first noticed the problem but didn't get any real help (surprisingly).

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On Wed, 10 Jun 2009 12:15:37 -0700 (PDT), "SonomaProducts.com"

There is an old thread on there regarding slop in the raising mechanism.
Try the search (in the forum.... search titles only) for
Another AND Powermatic AND 65
One of the hits will be Another Powermatic 65 Question
The discussion is about the same issue.
I would cut and paste it here but I'm not sure I'm supposed to do that from the forum.
Mike O.
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*snip*

Copying and pasting something from a discussion is fine, so long as proper attribution is given. The only trouble you run in to are copying and pasting copywrited material, or posting someone else's material without attribution. Usenet discussions are expected to be quoted.
Puckdropper
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reason why all trees have to be grounded..." -- Bored Borg on
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Thanks I'll look at that.
The Powermatic tech guy was very available, "sort of" knowledgable and very humorless. He wasn't familiar with 65 but "thinks" the 66 has a little slop in the two allen bolts that hold the "half moon" rack gear and I should be able to loosen them, tamp it into a tight position and tighten them down. I'll look at that tonight

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Glory!!!
All fixed. I really thought I was sunk. The rack (half moon) gear is attached to the arbor with two bolts through over sized holes. I had to strip off the motor and motor mount to get at the allen head bolts. I loosened them and was able to wedge a screw driver in and force the rack gear down into the worm while I tighetend the bolts. Killed 95% of the slop. I would like it to be 100% tight but it now just has the slighest play and the whole raising mechanism is now tight as a drum. I got the top miter slot and blade dialed back in to less than 1/1000 alignment front to back.

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SonomaProducts.com wrote:

... Great--I was wondering how that came out; couldn't imagine it was anything actually worn beyond repair...
My 66 is pushing 30 and while it's not an all-day every day usage, it's showing no signs of wear anywhere on the gearing afaict. I know there are much older that have far more use still going strong as well...
--
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On Wed, 10 Jun 2009 23:49:08 -0700 (PDT), "SonomaProducts.com"

If you have time to mess with it, could you post that over at OWWM? You seem to have found a solution that no one has talked about yet. It might also help the 66 guys. I'm sure everyone would be grateful.
Mike O.
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Will do.

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This 66 owner would graciously appreciate it.
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