I always wondered about the axle tubes being filled with hy guard on my 806.
I believe they hold maybe 4-5 gal each.
I'm thinking IH did that to keep oil to the outer outer axle bearings in the event the main housing reservoir went low.
I didn't drill the drain back holes in it or my cub cadet axle housing for that reason.
Just a thought as to possibly why the engineers chose to keep the housings full.

They fill the tubes through the carrier bearings but when you drain the trans it will only drain to the level of the bearing so it traps about 2 qts. I have actually seen a couple that had enough water in them that they froze and cracked the axel tubes. You have 2 ways to get the water out. If the rear is still in the tractor and you only need to stick a set of axel seals in it then just grab a suction gun and suck the crud out through the axle tube when you pull the axles for a seal replacement, but if you have the whole rear out with the axle tubes off it's only a few minute job to drill the holes through the tranny case to allow everything to drain when you do an oil change.

yes I know, thank you!!.
I decided to stay with the engineers idea.
Prolly not a problem on the little cubs drilling holes but thinking about 100 Hp pulling on the outer bearings in the axles with the opposite furrow wheel elevated when pulling a 5 bottom plow makes me want to have lube retained in there if possible.
there are housing drain plugs on my 806 so the lube can be drained along with condensation build up.
All my old horses get condensation drained every spring. and it it not unheard of, to drain over a quart of it out.
It is the nature of large castings to sweat inside on a warm moist day, after a cold night.
I have experenced a frozen gear case more than once on tractors that are not drained yearly.
Don't know about the newer ones built in the last 50 years though.

To drill or not to drill that is the question. We recently had the rear out of our 2072 and when we removed the axle tubes most of what came out was water. We drilled the holes and cleaned everything and reinstalled everything. Without the holes that water was trapped in the axle tubes with the probability of it freezing in the winter causing the tubes to crack. As to the possibility of a tube running dry, that will not happen as long as the fluid level in the tranny is kept at the full level. When the level is full it is well above the axle tubes and you would have to nearly lay it on its side to drain out an axle tube and run it that way to ruin a bearing. Since water is heavier than the oil rather than collecting in the axle tubes it would drain through the holes into the tranny. Periodic draining and changing the filter will take care of any water in the tranny.

Sam, do you have any measurements spec'd up that would allow the spot to drill the drain holes from inside the diff case and not require removing the rear end or removing the axle tubes? I have a right angle drill that should fit, plus, since there should be oil on the axle tube side, the flow of oil back into the center diff case once the holes are drilled should carry any chips back into the case from the axle tubes. Thoughts?

So here comes the noob question. Can we just drill a hole in the axle casing so that the water can always flow out? I'm expecting that this will not work or you would be doing it and would like to learn why please :)

There needs to be clean fluid in the tubes.

If you drill a hole in the axle casting itself your going to loose the lube oil as well (level is at approx height of diff carrier bearings).

Understood. I've never taken this part of the tractor apart. Thank you :biggrin2:

The outer axle bearing in an 806 axle is greased. No oil goes to it.

The only reason I can think of is like you said later during plowing, or uneven terrain it keeps oil in there. But it's not for the outer bearing. Not on that series. I was thinking on the 66 series, they added holes in the housing. Can't remember, and I'm not where I can look.