To whoever may see this. If you have a new style Udor gear reduction box, the sight glass is WRONG. If you fill it to the middle of the sight glass, it will blow the oil out the vented cap. Go with the recommended 9oz. Doesn't sound like much, but it is enough, and you will not see it in the sight glass,..unless it's running. Just posting an FYI.
Meh, no big deal in a gearbox. I rarely change mine and have no issues. Think about how often anyone changes gear oil in rear differentials in their vehicles. Some never have it done.
I prefer the thinner Mobil 1 75W-90 synthetic in my PW gearbox, my engine turns over better, especially in the cooler months.
(The only reason I could see changing it is if you question the amount, seeing how we don't have dipsticks, and in my case, the sight glass can't be used as an indicator. )
The sight glass thing I previously mentioned was confirmed to me by an Udor tech. He said the sight glass is incorrect, and to just use the recommended amount of 9oz. And it's no longer spewing oil out the vent cap, and is not having any lubrication issues.