Bush hog gearbox mount sideways?

[Canitbfixed]

Never looked inside of a gearbox like is on my bush hog, but would it ruin it to be mounted sideways to make a right angle gear box?

 

[RickB]

Not so long as you relocate the vent to the new top side. Fill to halfway up a horizontal shaft or a bit less.

 

[ROUSTABOUT]

As long as it is lubed, should be fine. We have gear boxes all over the farm. Same style mounted different ways.

 

[Vigo327]

A simple gearbox that is splash lubed wont care much as long as the fluid level is appropriate. It may take more oil in one direction than another depending on the shape of the case. Anything with an actual pump you have to be much more careful, but that doesn't apply here. Keep in mind too much oil will generally cause the oil to run hotter, not cooler. You just need enough that it is actually touching a spinning gear and getting splashed around.

Now a differential on a car/truck is a different beast because you SHOULD be able to drive those things basically nonstop forever with hundreds of HP going across it and proper lube is critical to that, but even though it's not what we're talking about here Gale Banks has posted a series of really interesting videos on youtube about what his company went through to test and design a differential cover in a way that did not degrade lubrication inside the differential. Easier said than done..

https://www.youtube.com/results?search_query=banks+differential+cover

 

[Canitbfixed]

Amazing quick responses. Thank you so much.

 

[CobyRupert]

I imagine that on most you could “extend” the vent plug with a threaded elbow and some pipe fittings so the vent stays on “top” .

 

[ning]

I imagine that on most you could “extend” the vent plug with a threaded elbow and some pipe fittings so the vent stays on “top” .

I suspect that the vent plug needs to be generally connected to the air space in the gear box. If you flip the gear box upside down and just make it so the vent plug is extended to be on top, oil could dribble out any time heat increased because the base of this new vent tube would be full of oil and an increase in pressure in the gear chamber would shove more oil into it; if the tube is long enough to expand without dribbling it would merely be a weak liability (catching stuff on it and breaking off the vent tube and/or threads at the gear box) instead of a constant mess.

 

[RickB]

I imagine that on most you could “extend” the vent plug with a threaded elbow and some pipe fittings so the vent stays on “top” .

That doesn't work if the entry point is submerged.

 

[PILOON]

Worst case, once orientation is determined drill and tap a breather hole at or near the top of the box.
Most boxes have a removable side or 'face' that would facilitate orientation.

 

[CobyRupert]

I imagine that on most you could “extend” the vent plug with a threaded elbow and some pipe fittings so the vent stays on “top” .

Good points on why this may not work if submerged. I stand corrected.

…but if the volume of oil and air expansion in the gear box is less than the volume of the extension tube, won’t that still limit the pressure that can build in the gear box that can blow out the seals? (i.e. limits the pressure to the “head” of the tube?) Worse case it pushes some oil out of the tube and not the seals?

 

[ning]

Good points on why this may not work if submerged. I stand corrected.

…but if the volume of oil and air expansion in the gear box is less than the volume of the extension tube, won’t that still limit the pressure that can build in the gear box that can blow out the seals? (i.e. limits the pressure to the “head” of the tube?) Worse case it pushes some oil out of the tube and not the seals?

Yes, it would work, especially if the vertical portion which is above the lube level had sufficient volume to handle the expansion, you may even avoid leaking lube during expansion. However, that tube would be a serious weak spot for that gearbox. I could see it working for a while but at some point something's going to hook onto that breather tube and break it off, and it could damage the threads of the gearbox where it's attached. I'd definitely look for an alternative for anything other than proof-of-concept.