It is most likely you will encounter similiar problems. I am not
familiar with mill/drills specifically but have done extensive work on
lathes and grinders. It is standard practice to have bearing inner
races fit to shafts with a tight slide to force fit. Likewise the
outer races will be anything from an easy slide fit to a force fit.
The fits are designed so any clearances/slop is in the bearings and
not between the shaft or housing. Depending upon the machine and
precision desired the bearings usually run some "preload" to eliminate
axial and radial play. Preload must be set correctly; too much and the
bearings run hot and fail early; too little and you have slop/play in
For example: We had a lathe that I had to take the main spindle out
with torches and a sledge hammer then cut the outer races out with a
die grinder. To reassemble I used dry ice to shrink the shaft and hot
oil to heat the bearings.
When pressing or driving bearings and races in & out it is important
to put the force in the correct place. Hammer/press on the outer race
to drive an inner race on and you have damaged the bearing. Same
thing for the outer race. Drive the outer race; do not apply force to
the inner race.
Hope this helps.
--- In firstname.lastname@example.org, "Don Greife" <dongreife@...> wrote:
> --- In email@example.com, "Don Greife" <dongreife@>
> > I have an older 33686, one that probably has seen better days, and
> > may be due for an extensive overhaul. I've considered the
> > possibility of replacing the bearings in the quill as a start,,,
> > have not yet attempted the disassembly. My hesitation is the
> > of an unpleasant experience with the replacement of the head
> > bearings in my Grizzly G4000 lathe. I asked Grizzly to replace
> > for me and was so unhappy with the result of the work done that I
> > bought another new set of bearings and races and replaced them
> > myself. This was the point at which I found the removal of the
> > bearing to be a real chore. It was a FORCE FIT on the spindle
> > and had to be driven off. I received two suggestions on how to
> > replace the bearings. An old millwright suggested that the spindle
> > should be placed in a freezer for an hour while the bearing should
> > be heated in an oven at 375* for an hour and then the two parts
> > should fit together nicely. The second suggestion I got was to use
> > emery cloth to reduce the diameter of the spindle to a "snug slide
> > on fit" for the bearings. I followed the second suggestion. Also,
> > during the bearing replacement process I found the removal of the
> > bearing races a real problem, but got them out with the aid of a
> > puller purchased for $9 and modified to do the job. With all this
> > said, and If I decide to rebuild the spindle on my 33686, and can
> > actually get it out of the machine, "is it likely" that I will
> > encounter similar problems replacing these bearings and races?
> MAybe it was just a dumb question !!!