10EE Spindle Slop 1947 s/n# 29802

Measuring on the D1-3 spindle taper I am getting very near the 50 millionths runout (damn its fun to say that) expected, when I do a torque test with the trusty broom handle I am seeing about 2/10 slop in the spindle. The spindle does not spring back to center.
Now...... If I apply to torque at the rear of the spindle I am getting about the same readings.
If the rear bearing was shot should I expect this 2-3 tenths reading at the spindle nose?
My thoughts are that if it were the forward bearing set, I would see less slop when applying force at the rear of the spindle vs. the front (wishful thinking?).
Can the rear bearing be replaced without removing the spindle? I would like to start by replacing the rear bearing and see if the spindle slop is fixed.
I get the impression from other posts that the spindle and front set can generally be removed without damage if one is careful.

What is a "torque test"

You mean checking the bearing for movement up and down?

I guess the real test is before we go out and start tearing it down, what sort of turning problems are you getting that means they need replacing?

The rear bearing is not a precision bearing like the front... Movement in it should not be a problem..

Torque was a poor choice of words. 'Radial Pry Test perhaps?' I put a bar into the spindle nose and applied 20-40 lbs force radially on the spindle. I have not run the lathe, its another "Wreck", and we are troubleshooting the drive system in other threads.

This morning I got around to checking the retaining ring inside the headstock. Loosened the two setscrews, locked the spindle and gave it two light taps in the 'tighten' direction. Could not perceive any movement, and it felt tight from the first tap. However now when I pry (lightly, 10lbf) on the spindle it still deflects about 3 tenths either direction but does consistently return to center (springs back). Measuring at the rear of the spindle I get 1-2 thou deflection.
Al least initially I intend to replace the "cheap" rear bearing and see where I am, It's a good excuse to tear down the headstock for paint.....

gernoff said:

. Measuring at the rear of the spindle I get 1-2 thou deflection.
Al least initially I intend to replace the "cheap" rear bearing and see where I am, It's a good excuse to tear down the headstock for paint.....

Click to expand...

If the rear bearing is a 5210 replacing it is not going to fix deflection if that bearing is free floating in there as I suspect it has to be (to allow for spindle expansion)

A modern 5210 bearing is not preloaded at the factory and has internal clearances.. I suspect the old 5210 bearings monarch used, did have factory installed preload..

If it has a pair of duplex 7210 bearings in there, they are preloaded...

Have not removed them as yet but according to the factory print there are a pair of bearings at the rear. The Monarch P/N# is 25867.

It is a double row bearing. I found one in FL that had the full complement of bearings (16 per row) marked 5210 on the inner ring, 23xx hand etched on the outer, and the box was marked 5210-W. It had a stamped metal retainer that was staked together, and marked New Departure. I found it on ebay. I got the impression that he had a few more.
There is another version with the same number without the -W suffix (new from Nachi) that has only 10 balls per row, and while dimensionally interchangeable, obviously not the same.

Lee (the saw guy)

Pulled the rear retainer plate off and all I can see is the etching '34XX' on the outer race. Is it safe to assume for my '47 lathe this is a 5210 bearing?

I've found the following bearings:
New Departure
5210-W
5210-WA
5210-(MAX)
From posts here it looks like the 5210-W is the correct bearing, any comments on the features of the WA and MAX designations.