David Privett and Hu Lowery have each reported recently finding a mysterious black metal spacer on the spindle of their new G0766 lathes after pulling the spindle pulley. Hu spoke with a Grizzly tech rep about it, who insisted it didn't belong there, and it is not depicted on either the G0766 parts diagram or parts list. This surprised me, as the exact thing happened to me over two years ago with my then-new G0733 ("little" brother of the G0766) when I pulled the spindle pulley. I reported it to Grizzly, and described the issue in a July 2013 tutorial on building a vacuum chucking system and an integrated handwheel/vacuum adapter. Evidently, tech reps at Grizzly are still unaware that this extraneous metal spacer is being installed at the factory on the spindles of these two lathes, and it is still not shown in either the parts diagrams or the parts lists. (cont)
This otherwise marginal issue on these excellent lathes is important because the spacer is held in place behind the spindle pulley only with thick packing grease, and the bore of the spacer, at least on the G0733, is actually larger than the diameter of the spindle! Thus, it can come loose and create a rattling sound and knock that closely mimics a bad bearing. I've started this separate thread on the issue to make it easier to find in the SMC archives and Google searches. Perhaps the discussion may help some current or future G0733 or G0766 owner. I have posted a photo of the mystery spacer in the GGMG's photo gallery, as photos cannot be reproduced in the body of SMC group threads. I am pasting the relevant excerpt about the issue from my tutorial below. Because of the 1000 character limit to group posts, the excerpt is broken in parts. Anyone wanting a full copy should PM me separately with an email address, as the file is unfortunately too large to post via SMC. (cont)
Excerpt from July 2013 tutorial: The extraneous spacer ‐ to keep or not to keep? Regardless of whether you opt to move the spindle pulley, but especially if you do, you should be aware that the Grizzly G0733 ships with a steel spacer on the spindle, between the spindle pulley and the outer bearing of the headstock. I do not know if one is present on the G0698 or other makes of 18‐47 lathes, but assume it may if they come from, or are assembled in, the same factory. The spacer is curiously not shown or listed on any parts diagram or parts list for the G0733 or G0698, nor is it referenced in the Owner's Manual. Here is a photo: The spacer's apparent purpose is to facilitate positioning of the spindle pulley during installation. My spacer was held in place against the pulley only with thick grease. Surprisingly, it's bore is actually larger than the diameter of the spindle, and if it ever slips out of concentricity with the spindle, (cont)
it will cause an imbalance and quite a racket. I know this because it happened on my lathe after a few weeks of use, before I undertook this handwheel and vacuum adapter project. When it happened, my first thought was that the noise was from improper belt tension adjustment or, worse, a bad bearing. A bit of troubleshooting found the loose spacer behind the pulley, yet I could find no reference to it in the parts diagram or parts list in the Owner's Manual. After discussing this with Grizzly Technical Support (who also could find no reference to it in their parts lists or manuals), I concluded that the spacer adds nothing to functionality. I removed it altogether, first removing the pulley, and the lathe once again was whisper quite at all speeds. The spacer now reposes in my extraneous parts drawer. Whether you choose to remove this part is up to you, of course. If you never move your spindle pulley, (cont)
it may never become an issue, although it did for me. But if your lathe ever develops an odd knock or tick coming from the headstock that seems to be speed‐related, this is the next thing I'd check, after checking for excessive belt tension and for loose set screws on the spindle and motor pulleys. (End of excerpt)
My install was completely dry, everything in the headstock of my 766. The spacer made a slight noise when the machine was first ran and rapidly became a clatter because as David accurately notes, the spacer doesn't fit the spindle snuggly. Mine too resides in my junk drawer. It might be a helpful bearing install tool if I ever need to use one of my two spare sets of bearings! I ordered new bearings before tearing down my headstock as it did indeed mimic a dry bearing from the factory. Hu
Great thread David & Hu.......I have not checked to see whether my G0766 has this spacer or not, but my lathe runs very quiet, but next time I do a belt adjustment on the pulleys, I am going to look for it.
I believe that the spacer is there to provide a clearance between the drive pulley and the inner barrel ( I do not think it is actually a race) of the bearing. If the pulley was to be tightened under some circumstances the inner barrel and the outer barrel of the bearing would be semi locked together instead of turning separate of each other. I think what has to happen is the spanner nut has to loaded and then slightly loosened ( I used 1/8 turn max.) then the pulley screws tightened . And as I addressed before I used a second set of set screws as a jam nut to prevent them from loosing up. And also look at the spacer you will see it was manf. for a purpose not just a washer. Fyi the smaller dia. tooled ring goes toward the bearing. That is my opinion anyway.
I've added a second photo of the spacer, showing its reverse side. As seen in the two pics, there is a recess, or rebate, on one side of the spacer and a tenon on the other side. The bore (at least on the G0733) is not a snug press fit to the spindle diameter. So, for the spacer to remain stable, without chatter, either the recess on its one side, or the tenon on the other, must mate with an adjoining surface that is concentrically stable. Yet, the backside of the spindle pulley is flush, so nothing there to mate with the rebate on the spacer. And on the opposite (bearing) side of the spacer, I could find no obvious matching recess to receive the spacer's tenon. But perhaps there is one, judging from David Privett's observations. I did not investigate this closely for a couple of reasons. First, neither the parts diagram nor the parts list showed the spacer, and the Grizzly techs could find no indication in their documentation that it should even (cont)
be there in the first place. Second, for my handwheel/vacuum adapter design, I wanted to move the spindle pulley about two millimeters farther toward the outboard end of the spindle for better alignment, which meant that the spacer would be even looser on the spindle, and at that point be even more extraneous. Perhaps the next owner of a G0766 or G0733 who pulls their spindle pulley can look a bit more closely at this particular issue and shed some light. In the meantime, I think it is enough just to be aware of it in case odd noises start coming from inside the headstock casting!
