oil foaming in milling machine gear box

Changed the oil in my milling machine gear box .
It's a splash system no pumps or filters . (Abene)
The manual calls for shell telus 29 which is now
shell telus 46 which is what I put in. Seems a little light to me . In any case it is foaming ,
building up right away on start up. I called Shell and the guy said to try Omala 68 gear oil.
I do see a posting online from Abene that calls for
Mobil 600 XP 68 . Don't like the foam .Any insight would be mighty welcome .
Thanks, Ted

I'm not a oil expert so keep that in mind. If the oil you put in is the the oil companys approved replacement for the original oil what's to worry about? I bet they have studied it.
Is the oil supposed to foam to lube upper bearings?

It's not hydraulics so I wouldn't worry over much about it, lots of gearboxes foam, and putting in thicker oil is often a bad move, ..........it tends to get thrown from where it should be and not being thin doesn't drain back as quickly as it should, ..........great way to cook gearbox bearings.

That's my take, but on pondering;-

I suppose you could try looking for an equivalent hydraulic oil - as they have anti foaming additives.

Tellus S2 M 46 a a hydraulic oil and is supposed to be anti foam. Where did you get it? How sure are you that you got the correct oil? There are 9 product lines called Tellus.

tdmidget said:

Tellus S2 M 46 a a hydraulic oil and is supposed to be anti foam. Where did you get it? How sure are you that you got the correct oil? There are 9 product lines called Tellus.

Click to expand...

There is a Mobile DTE series hydraulic oil that Clausing folk use in headstock and apron gearboxes, replacing the original Tellus oils. Given the ISO viscosity, which DTE to use is clear.

Ted, Sir
Hey I run mobil dte medium ( ISO 46 wt) circulating oil in my 1937 Cincinnati 2L milling machine.. You want an almost additive free oil.. ( no detergents and extreme pressure additives) Just good old circulating oils.. I find this best for older machines.. My W&S #3 had some god awful tractor supply oil in it and it almost foamed out the top of the machine ! Looked like a 3 stooges washing machine skit when I popped the covers.. I saved a jar of the oil foam mess for over two years in the shop just to see what would become of it.. What ever was in it never separated out ( water perhaps? ). It would seem automotive stuff with certain additives hold water and dirt til the water cooks out and til the filter gets the dirt.. Yes, I realize you are trying to put the 'right' oil in your machine but maybe shell put additives in the 'new' formulation.. Just a thought for ya..
Anyhow mobil circulating oil separates out water and debris at room temp in minutes.. Never had a foaming issues with it in years of use.
Hope this helps some
Stay safe
Calvin B

Thank you all for the input .
The oil I'm using is Shell tellus s2 mx 46 (hydraulic) .
I'm not bothered by the foaming unless it's causing damage .
Read lots of horror stories ,though related mostly to hydraulic systems . It's hard to believe it's not getting enough lubrication given the oil storm that must be going on in there .
Ted

Some gearboxes just foam - because they just do, ..........much as 60's & 70's** TOS lathe headstocks run a lot hotter than almost any other lathe - with no ill effects.

** I can't comment on later machines.

As you say - with the oil storm maelstrom that's going on in that box - given the stated grade of oil, I also think everything's getting enough lube.

I have a 50+ year old gearbox out in the garage, attached to my Sunbeam Alpine. They specify non-detergent motor oil for it, with a type still available in auto parts stores. Helical-cut gears, no pump/just splash (for the gears). Pump involved in OD, however...

Now that the headstock is 'clean', I'd switch to verified non-detergent if it were mine.