Rotary Cutter Best gearbox oil change methods, brush hog.

Coyote machine · Oct 27, 2015

Want to change the gear oil in the gearbox on my Woods BrushBull BB72X. There is a vent that screws into the top flat cover plate on the gearbox through which one fills the gearbox until the oil leaks out the side plug port. My question is what do you do to drain the gearbox to get the old greenish colored very stinky gear oil out?
I thought about unbolting the top cover plate and siphoning the oil out, but isn't there some easier way? I guess I could do the same idea through the vent port but I want the gearbox as clean as possible before filling it with new oil.

Any ideas appreciated!

TIA,

CM

ruffdog · Oct 27, 2015

The lower bearings is where the moisture and grime sits. Flip the deck and let it drain for a day.

Coyote machine · Oct 28, 2015

Really? The whole unit is over 700#s ? It sounds like a good way, I guess...Have you done this before? Is there no other way?

Thanks.

CM

quicksandfarmer · Oct 28, 2015

I pump it out with an oil change pump. Run the cutter for a while first to warm up the oil.

TomSeller · Oct 28, 2015

I'd tend to think connecting to one side with a chain and backhoe or excavator bucket and flipping it over, adjusting boom and dipper As I went. I'd do it side to side, not end to end. I use the loader on mine to flip the back end up against a tree when wanting to do maintenance. I make sure I get a good lean against the tree. In your case you'll need some saw horses or something and go to opposite sides until you have it where you want it. Or on the hand, sucking it out with a tube sounds like a good idea. Or unbolt the gearbox and flip just it over.

cat fever · Oct 28, 2015

I had a similar problem with my haybine. There is no drain hole for changing the gear oil out. I siphoned mine out with a small clear hose that took a couple hours because it was so thick and way overfilled. I'd like to do it a couple more times just to clean it up real good.

MESSMAKER · Oct 28, 2015

Coyote machine said:
Really? The whole unit is over 700#s ? It sounds like a good way, I guess...Have you done this before? Is there no other way?

Thanks.

CM

Flipping a cutter over is a five minute job with a loader or a boom. I am not sure that I would worry about it much. You will eventually ruin the seal and it will drain out on it's own. Then you replace the seal and lube or switch to Cornhead grease.

LD1 · Oct 28, 2015

I have never changed any of my BH gearboxes. Just keep em full. When the seal goes out, replace and refill.

Greenish tint and smelly sounds like new gear lube:thumbsup:

If you insist on changing it, use your loader and flip it, or take the stump jumper off and the few bolts holding it to the deck and remobe the whole thing

smstonypoint · Oct 28, 2015

LD1 said:
Greenish tint and smelly sounds like new gear lube:thumbsup:

I don't know about Woods, but I seem to remember reading on TBN that some manufacturers are now specifying corn head grease (NLGI grade 0) for use in their rotary cutters.

Steve

LD1 · Oct 28, 2015

smstonypoint said:
I don't know about Woods, but I seem to remember reading on TBN that some manufacturers are now specifying corn head grease (NLGI grade 0) for use in their rotary cutters.

Steve

Wouldnt surprise me.

Sometimes I top off with GL, sometimes I top off with 00 grease. No rhyme or reason, just whatever I grab.