I could use the assistance of anybody familiar with milling machine spindle bearings, in particular anybody familiar with the lower "Timken" bearings on an older Burke Millrite spindle.
I've never serviced the lower spindle bearings and today, after running the mill for about 15 minutes at the highest possible spindle speed, (which I've never done before), I noticed that the bottom of the quill had become too hot to touch.
After letting it cool down I reset the drive belt to run at a lower speed but noticed the quill was still warming up although not as bad. Maybe it's been doing this for a while and I just hadn't noticed.
At this point it seemed a good idea to check the lower bearings for sufficient lube and proper axial preload as, in the service manual, these are the listed causes of this end of the spindle running hot (other than shot bearings altogether).
Per the manual, if you drop the quill all the way down it exposes a threaded plug in the side of the quill that can be removed with a 5/16" hex key to lubricate or adjust preload on the lower spindle bearings.
However the quill plug on my mill has a curious arrangment occupying the
5/16" hex socket in the plug which precludes being able to engage the plug with a hex key. It appears to be something in the way of a "half Alemite" fitting that somebody made up and inserted to facilitate oiling the lower bearings without removing the plug. At least this is what the guy at DC Morrison (they handle Burke Millrite machines) postulated when I described it over the phone. Even if this is what it is, efforts to pass oil through the fitting in the plug did not appear to be very effective, most/all of the oil coming out of the spout just dripped down the outside of the quill .Before I attack this setup with a drill and an easy out, so that I can remove the plug and properly lube/adjust the bearings, I thought I'd post a couple of pictures to the drop box for scrutiny by those more knowlegeable than I, to confirm that this arrangement is not stock/proper and that I'm not going to mess any thing up by removing this " modified oil port" in the hex socket of the plug.
The jpgs of the quill plug are at:
In particular if there's anybody who has a Burke Millrite that could maybe check the quill plug on their mill and compare it to the posted jpgs to establish whether it's the same or different than my quill plug, that would be great.
Thanks,
Dennis van Dam