17" Turn-Nado spindle bearings

I work for a cryogenic equipment manufacturer. We have mostly CNC machines. In addition, there are a lot of old manual machines, including 2 old Turn-Nados. Today I got a maintenance request to investigate a noise in one of them, and it turned out to be a bad spindle bearing.

I started taking it apart this afternoon, and am proceeding slowly and cautiously, because I'm relatively ignorant and don't want to break anything. We are ill equipped to do this sort of repair, though I did fix the cross feed/longitudinal feed on this machine about 8 years ago with success (I joined Practical Machinist specifically to ask for advice on the job).

My resources are limited to an old owners manual made up of faded and grease stained Xerox copies, and whatever advice I can get from various contacts I have, which to say, not much. I would prefer to ship the headstock to somebody, and let them fix it, but after a few internet searches and phone calls, it looks like that may be a dead end. Meanwhile I'm on my own.

Can anyone give me a little advice on pulling the spindle and replacing the bearings? I would be grateful for any and all help.

Thank you,
TomR

replacing the bearings?

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For one thing, they have to be precision class bearings. For instance, if they turned out to be Timken taper roller bearings they would be Class 0

These items may cost more than the "old manual lathe" is worth

perhaps give us a little rundown on the condition, wear on the ways, backlash on the cross feed screw, pictures. that would help to determine if its worth the effort and cost. good luck!

We have a 17" Clausing Turn-nado. bought new around 86. Not that old in my book. And Clausing still sells parts for this machine.

I would investigate why it needs new spindle bearings before removing all the evidence. And I wouldnt replace spindle bearings for just noise. If it still makes good parts who cares.

I know from first hand experience that water miscible coolant will rust a hole in the wall separating it from the headstock oil. Then you will have water inside the headstock.

Despite being a high speed spindle, I dont recall it looking substantially any different than any other lathe. Just more gears. And english sillyness like the drysump headstock.

The spindle bearings do not HAVE to be precision class. It depends on what you want to do with the lathe. I had to replace the taper roller bearings in my old Sheldon 10" and I talked with one of the sales engineers at Timken who told me that they offer different precision levels in the same size bearings. At the time, a set of precision bearings for the Sheldon was going to be north of $350 each (15 years ago) so I opted for something a little less fancy. I never had any trouble with the "cheap" bearings and never noticed any problem with turning to .001" tolerance that I could blame on the bearings.

Thank you for your replies.

TomR

Good stuff from Timken Engineering. They gathered this data and published it. Maybe people even digest it now and then. A good piece of it shows the Class 0 to have but 10% the Assembled Runout that the Class 2 gear box bearings had