Ken Moffett wrote:

I have a South Bend 10K model A lathe with a "frozen" bearing on the
right end of the lead screw. I pulled the quick change gearbox and the
bearing mount loose, so I could pull it off the shaft. The casting can
be turned on the end of the lead screw shaft, but only with a great deal
of force. And, it isn't going to slide off. In the manual it shows a
little block of babbit associated with the one piece casting. In the
back of the casting are two ~1/4" holes filled with babbit.


If it is really Babbit, it should be possible to wring the bearing off
the shaft.
Of course, it will chew up the bearing a bit, but it is already in trouble.
If it is actually a bronze bushing, it may be VERY difficult to get it off.
You should try to work a light oil into the bearing, and keep twisting it
back and forth and try to get the bearing moving off the end of the screw.

If you can get them separated, you should be able to clean up the end
of the screw and ream out the bearing. If it is not too badly mangled, you
might be able to just lube it good and put it back together. If not,
you can look at making up a bronze insert. Even without the leadscrew,
your lathe is the perfect machine to repair this part.

But, if repouring the babbit is the way you want to go, it is not that hard.
First, you melt out the old babbit. Then, you probably need some more
babbit metal to make enough to repour. You may or may not need "dams"
to keep the babbit from leaking out the ends. You use a candle or acetylene
(without the Oxygen) flame to soot up the shaft. general practice is to
put 3 layers of soot on the shaft. Insert the shaft into the casting and
align it in the bore with whatever method will work. Apply dams to
the ends if there is a lot of clearance. Centering plugs of wood can
do both the aligning and damming function in one, and can be cut on
the lathe. make from wood so they don't get soldered to the bearing.
Now, you pour the babbit into the bearing - you may want to preheat the
casting a bit first. When it has cooled, you pull the shaft out. If you
got enough soot on it, it won't be terribly hard to pull out. A little
careful reaming and drilling of oil holes should be all that is needed,
and it will be ready to go. This is a low-speed bearing, and a lot less
critical than a spindle bearing, say.

Jon