Proper Lathe Chuck Jaw Positioning when Assembling

[aztoyman]

Total newb here. I have a couple crusty chucks for my new to me lathe. Both 6" with 1 1/2"-8 spindle threads. One a 3 jaw and one a 4 jaw.

I decided to take them apart to clean out the crud and rust. The 3 jaw had all the jaws numbered and a corresponding number on the "body"? of the chuck. I did not remove the back just used a wire brush and solvent to clean it all up. Anyway the 3 jaw went together exactly as it was.

The 4 jaw has numbers on the chuck near each slot but no numbers on the jaws or screws. I marked them all with a sharpie just to avoid mixing them up. I just used a wire brush and solvent to clean out the old crud.

The 3 jaw is an old Union, the 4 jaw is an old Cushman. Now my questions.

Does it really matter which jaw goes where on the 4 jaw independent chuck? What should I use for lube inside these bad boys?

Sorry if this has been covered before. I just spent quite a while using the search function on just about all the forum sections. Maybe I need better key words. I even just used "chuck". Didn't find what I was looking for.

 

[darkzero]

Does it really matter which jaw goes where on the 4 jaw independent chuck? What should I use for lube inside these bad boys?

On the 4-jaw it really doesn't matter as much as it does on a scroll chuck like the 3-jaw. The jaws may be fitted to a certain slot & fit better. It sounds like you have 2 pc jaws? Usually they are fitted as well, the top & bottom jaws are marked on mine but not on all chucks obviously.

I only use chuck grease (specifically Gleitmo 805, but there are plenty of other suitable greases you can use) for inside the chuck (backside of the scroll & pinions) & use only oil for the scroll/jaws. Using grease on the scroll side will just collect chips & other debris quickly. On an independent 4-jaw I would use just oil too but I currently still have the grease on it that came on the chuck when I bought it.

 

[aztoyman]

Thanks for the reply. I figured there would be some kind of tool specific lube. The two chucks I was referring to looked like they had never been cleaned up. The grease was hardened up and cracking on the 3 jaw. (The one I got with the lathe is also rusty)

I got another 3 jaw N.O.S that operates nice and smooth. Two sets of jaws and the numbers match. The 4 jaw is "supposed to be N.O.S. isn't rusty and all the crud "MAY" be old Cosmoline or something. It only has one set of jaws but, I cant find a number anywhere on the jaws.

Its going back together as I marked it anyway. I didn't think it would matter on the 4 jaw. It threw me when the chuck itself has numbers by the slots. Maybe somebody sold me a chuck they put together from parts they had? Seems to fit together real nice.