Front axle oil fill level

[TVZ]

The manual to my 1726E says to "make sure the oil level is at the mid point of the front axle housing." Here's the diagram. The fill plug is #1. It looks to me like the mid-point of the axle housing is about 4" below the top of the fill plug hole.

Here's a photo of the front axle oil fill plug (upside-down). So what's with the peculiar configuration of the fill plug? It kind of looks like it's supposed to serve as a dipstick, like maybe the oil should be at the upper part of the bottom of the plug (the left side of the bottom in this inverted view). Is the level really supposed to be at the mid-point of the housing, several inches below the fill plug? And if so, are we supposed to make our own dipstick to determine the level?

 

[Dmacleo]

lot of self vented plugs on many different apps/machines look like that. not saying that is self vented but very possible it is as actual axle prob does not have a vent.

 

[hube2]

Same setup and owners manual instructions on my tractor. There isn't a dipstick and you aren't supposed to use one. Just shine a light into the opening. You should see a bevel gear. The fluid level should be at the mid point of that gear, which is the mid point of the housing because the shaft is in the middle of the housing.

I have no idea why the end of the oil fill plug is angled because the long end does not even reach the top of the bevel gear when tight, at least not on my tractor.

 

[DMW]

The fill plug contains a spring loaded breather valve to prevent pressure buildup in the front axle when it gets hot. It is plastic, do not over tighten. It is a plug, not a bolt.