I recentely disassembled the headstock on my 12" Atlas lathe to install
a new drive belt.

I'm now getting some extremely rough cuts with both SS and brass stock,
and quite a bit of vibration during the cuts.

If I put side pressure on the 3-jaw chuck that I'm using, I can feel a
slight side-play that I'd estimate to be a least a couple of mils, so
I'm suspect that the problem is excessive play in the Timkin headstock
bearings.

My problem is that I've tightened the ajustment nut on the headstock
shaft as tight as I can get it, which doesn't seem to be tight enough
since still the shaft sideplay still exists.

Am I doing something wrong, or do I need a new set of Timkin bearings?
Is something possibly locking the headstock shaft so that the proper
Timkin bearing tension cannot be achieved?

To make matters worse, when I run the lathe in backgrear, it runs just
fine except that there is a slight clanging noise that appear to be
from the step pulley.

I suspect that when I reassembled the headstock, I did something wrong,
but I can't seem to locate what it might have been.

Any suggestions?

Harry C.