Play (longitudinal) in lead screw

I have a double tumbler 9a, with an apparently loose lead screw. When the screw is disengaged, I can grab it and move it left to right--quite a bit of slop. Before I take the gear box & screw off, Is there anything I should look out for? I'm assuming (hoping) it's just a loose nut in there somewhere. I can't find a diagram that shows the lead screw inside the box.

Thanks

Perhaps you could peek under the quick change box with a mirror and flashlight. While I have never worked on a 9"
gearbox, I assume (perhaps erroneously) the design is similar to the heavy 10,13",14.5", and 16". Inside the gearbox, mounted on the leadscrew is a bearing, a hubbed gear (which puts the teeth on the gear in mesh with the
second gear on the gear "cone". This hubbed gear is retained on the leadscrew with a washer and nut. I have seen
double nuts, and a single lock nut, on different gear boxes. It's been a few years since I had one apart, but if the retaining nut comes loose, or off, the leadscrew can float between the outside edge of the gearbox, and the leadscrew support bearing on the tailstock end of the bed Hope this helps. PB

No bearing on the 9s...it's pretty common for them to develop some slop.

How much slop are we talking??

It's about 1/8"

Ya, that's a lot.

IIRC it was about .004" from the factory.

I would say time to pop the gearbox off, or even just flip the whole lathe over and have a look see.

A gear end photo here
1947 9A South Bend Lathe Rebuild.| Builds and Project Cars forum |

Thanks for that.