[Steelmesh]

Chinese beer? See image below, this is 10 seconds after the very first time turning the spindle on. Just checking if this is normal. I have some Mobile DTE 26 standing by.

[vertcnc]

If that was what came with the mill, I probably would have dumped it out right away. If i remember right i used light weight hydraulic oil, which is similar to dte26. Transmission fluid would also work. I do remember some light foaming. You know the best way to correct the problem is to dump the gears into the crap bin and go with belt drive. Quiet and variable speed.

[Steelmesh]

If that was what came with the mill, I probably would have dumped it out right away. If i remember right i used light weight hydraulic oil, which is similar to dte26. Transmission fluid would also work. I do remember some light foaming. You know the best way to correct the problem is to dump the gears into the crap bin and go with belt drive. Quiet and variable speed.

I will do an oil change for now. I assume you're referring to the COA belt drive upgrade? Thanks for the advice.

[Charter Oak]

The "factory" oil is always flushed and replaced prior to the mill shipping out. There should be no reason to change out what is currently in the head for some time. There will always be visible aeration in the sight glass while the mill is running. The sight glass is showing the surface of the oil, and does not necessarily represent the conditions down below. The sight glass is also positioned towards the rear of the head directly next to the primary drive gear shaft, which means that even if your spindle is running in low gear, the motor (and the shaft below) are still turning at full speed, creating the most turbulence. We would not recommend using automatic transmission fluid in the gear head by any means.
Hope that this answer helps.
COA