I have a couple of Ex-Cell-O Knee mills that originally had Vari-speed spindle but now are VFD, they have a two speed gearbox that is 1:1 and 6.5:1.
In the original manuals the recommended lube for the gearbox was SAE 30, I have obtained a later manual for the exact same machine and in it they 'Type "A" automatic transmission fluid provides superior protection and is recomended'
I contacted XLO and the person I spoke to could not tell me when and why they changed over, only that this is now recommended.
I have never seen auto Transmission fluid used in a ordinary gearbox before. Has anyone else?
Al.

Al, I can't tell you anything about mill gearboxes but (to the best of my knowledge) the only difference between ATF and SAE30 is that ATF works well with the clutch packs inside a automatic tranny. If motor oil was used in an automatic, the clutch packs would slip. Considering how low tech a mill g/box is (they have neither synchro rings (manual) nor clutch packs (auto)), I can't see a problem running either. As for the claim that ATF offers superior protection for the gears, I very much doubt it. So with that in mind and also considering it is significantly more expensive, I wouldn't bother.

ATF keeps seals soft, so on an older machine it wouldn't hurt.

The documentation I have my my spindle wizard which has the same gear box doesn't recomend 30w or atf. It recomends amga #5 ep....which makes a lot more sense.



If you really want to get fancy with it you could add some of the dow corning molykote m gear guard dispersion. That's the lube the spindle wizard uses for the tubular ways on the fancy position wizard table. It's made to be added to gear oil though. You really can't be moly additives..and it's 10%.

The new GM ATF (Dexron 6) is more resistant to foaming and less abusive to copper alloys (brass,bronze etc.) used as bushing type bearings, bearing cages etc. I was "influenced" by recommendations of a few other "old farts" on the 'Zone. In all applications where I used ATF it worked fine, especially where I previously had foaming problems.

I believe it would be a fine gear lube since an automatic transmission has a bunch of planetary gears in it. Probably better heat transfer as well.

This ATF is a synthetic and might be more prone to leaking than a non-synthetic or straight 30W oil.

Dick Z

Since that post was started about 3 yrs ago, I have been using the ATF since then, so far so good, Before I changed over, I had to repair the bronze gear shifter which had worn quite dramatically.
Al.

I did not look at the date of the original posting, SABT. I didn't mean to to imply that ATF in general was abusive to copper alloys. Only that the newer ATF's were less abusive than straight mineral (petroleum) oils. Normally, there are additives to prevent copper alloy degradation and extreme pressure capability. When the application involves those problems, such as bronze worm-wheel/worm interface, the new ATF's do an even better job reducing the problem, as well as the bushing type bearings etc.

Dick Z

woops, that was me that dug this thread up. No particular reason. I just happened across it looking for ex-cell-o stuff and thought I'd throw in my 2 cents (right or wrong as my 2 cents maybe). If atf works well it works well. I don't know, I just have a reaction of "wow isn't that awfully light oil?" Of course I haven't changed the gear oil yet so I don't even know what agma 5 ep looks like.

This thread, ancient though it is, jogged a memory.

Where has NC Cams disappeared to?

Geof, He's one of the "old farts" I referred to in #5 above. He may be PO'd at us. lol

Dick Z

Geof, He's one of the "old farts" I referred to in #5 above. He may be PO'd at us. lol

Dick Z

I didn't think he was one to restrain his PO'dness. :D