Rotary Cutter Easier way to change gear box oil

[two4spooky]

I have learned so much from this site I wanted to share, maybe help in some small way. The issue I had seems to be fairly common; water mixed with the gear box oil. The difficulty is the gear boxes do not have a drian plug, mine only has the breather/dip stick and check level plug. To drain the gear box I needed to either a) lift the cutter on it's side to have the check level plug down (not ideal as the mower weights 1100 lbs) or b) suck the oil out (90wt is bit thick). My helper and I decided "b" sounded a bit safer. I do not have a pump(added to the want list) that would work but I did have some tubing and a rubber sqeeze bulb for adding water to batteries. I learned it takes a LONG time using the bulb to suck 90wt. from a gear box. Even with the cutter deck blocked up on the off side and the oil thinned with water the milky fluid is too thick. Did I mention it takes a long, long time with the bulb? The effort saver was to use the tubing to siphon the oil to a container at a lower lever. Get it started flowing then go fix a cup of coffee while gravity does the rest. :thumbsup: So after draining and refilling the gear box oil four times I learned: 1) start with deisel fuel(THANKS Soundguy!) to wash out the box, 2) use motor oil next -thinner than gear oil and I had a bit on the shelf, 3) if you do not have a small drill pump use gravity to siphon the oil out. Anywho...TBN'ers probably already knew all this but for me it was new. A couple of pics of my mess and my helper

 

[Sackett2]

Vacula 12-016-1000 DX 2.5 Brake Bleeder / Fluid Evacuator

A bit spendy, but can be used on any fluids, just the gear oil is a bit slower.

 

[Wolfy]

I have 2 hound/helpers, quite dependable. I think a drill mounted pump might work on gear oil.

 

[Hughman]

I just used this one to transfer 8gal of hydro fluid. I haven't tried it on thicker gear oil yet but for $6, it might be worth a try. You can either pump the entire contents or use it to start a siphon if the drain bucket is lower than the gear box.

Multi-Use Transfer Pump

 

[clemsonfor]

I would have used a chain and the FEL to flip it over myself. put some wood stumps or jackstands under it and pull the plugs. Seems much easier to me.

 

[SandburRanch]

I would have used a chain and the FEL to flip it over myself. put some wood stumps or jackstands under it and pull the plugs. Seems much easier to me.

-------------------------------------------------------------------
You would miss out on the cup of coffee.:laughing: And sometimes good things take just a little longer.

 

[RiZak]

I always had beter luck with a drill, a drill bit and a 3/8 npt tap. The very first time I need to change oil in one gearbox I chose the best spot to drill a hole and install a short nipple with a cap. No need to worry about metal going in the casing since I will be able to deep clean the gearbox. I use to stick a magnet on the cap but for the last couple years I prefer installing a nipple to minimise the spill. Once empty and cleaned with fuel I insert a magnet in to pick up any possible piece of metal in the bottom of the casing. It usually take less than 15 minutes to completely clean a gearbox. Wich is about the time between starting the coffee pot and having it ready to drink with clean hands and no unbalanced load getting ready to crush me.

 

[two4spooky]

For the few times I need the pump I think this would be good and there is a HF close to work. Off to HF tomorrow!

I just used this one to transfer 8gal of hydro fluid. I haven't tried it on thicker gear oil yet but for $6, it might be worth a try. You can either pump the entire contents or use it to start a siphon if the drain bucket is lower than the gear box.

Multi-Use Transfer Pump

 

[two4spooky]

The problem is needing to get the cutter close to 90 degrees vertical. My helper is not too smooth on the loader controls. :laughing: Plus I ran the cutter in between refills which really helped get the water out. Mount, hook up PTO, unhook PTO, unmount and repeat would be "a little too much sugar for a nickle".

I would have used a chain and the FEL to flip it over myself. put some wood stumps or jackstands under it and pull the plugs. Seems much easier to me.

 

[two4spooky]

This would be ideal. I can not for the life of me figure out why these gear boxes do not have a drain plug. It seems changing the oil would be a regular maintence item, especially since the box is vented. I may feel brave this week end and follow your lead. Great idea RiZak!

I always had beter luck with a drill, a drill bit and a 3/8 npt tap.

 

[Transit]

90 weight gear oil is equal to 10 weight motor oil, they are measured on different scales, not the same scale. Check out sites that have all the scales side by side.

 

[Combustix]

hey how often do you change the gear box oil. I run my brush cutter around 7-15 hours a year. I have been changing at the end of the season but was wondering if this may be to much. Oil always looks good when it comes out, and I know this is cheap insurance, any way looking for some input. thanks

 

[boggen]

perfect timing!

put the #90 transmission oil. what the "new idea" 425 rotatory cutter manual noted, on the todo buy list earlier today.

i am not going to like cleaning this gear box. unscrewed the cap to check. and all i could see was old nasty clumps of grease inside. and no oil level what so ever. ((recently bought this at an auction))

to be honest the manual i found at AGCO Parts Books doesn't list oil level? i am assuming just fill it up to point it about to overflow out of the cap hole?

===============
as far as diesel, you hooked it up to tractor. and left diesel in it. while it ran for? how long?

same Q for motor oil?

 

[two4spooky]

Combustix- I am not an expert but your schedule(end of year) sounds good to me. Like you say "cheap insurance", equipment is too expensive to not maintain. ------------------------------------------------------------------------- boggen- I would not put a load on the cutter with deisel in it. Just let it spin at idle for a minute or two. With the motor oil in I cut for about 15 or 20 minutes each time between refilling, this seemed to really help. My tractor/rotary cutter combination cuts lite stuff well at lower RPM @1500-1700. This is how I ran it with motor oil in, I did not want load the cutter too bad. ****Carefull checking the level first time. The breather had failed on my gear box and the box had pressure on it. Gear oil sprayed everywhere, including on me. Nothing smells (or taste) like gear oil.

 

[clemsonfor]

The problem is needing to get the cutter close to 90 degrees vertical. My helper is not too smooth on the loader controls. :laughing: Plus I ran the cutter in between refills which really helped get the water out. Mount, hook up PTO, unhook PTO, unmount and repeat would be "a little too much sugar for a nickle".

90 degrees i think would be easy, just hook to the 3pt and lift. I would have sprayed deisel out of a spray bottle in it or just let flat filled with deisel and then verticle again.

Your gonna get water again unless you can figure out how it got there.

 

[clemsonfor]

perfect timing!

put the #90 transmission oil. what the "new idea" 425 rotatory cutter manual noted, on the todo buy list earlier today.

i am not going to like cleaning this gear box. unscrewed the cap to check. and all i could see was old nasty clumps of grease inside. and no oil level what so ever. ((recently bought this at an auction))

to be honest the manual i found at AGCO Parts Books doesn't list oil level? i am assuming just fill it up to point it about to overflow out of the cap hole?

===============
as far as diesel, you hooked it up to tractor. and left diesel in it. while it ran for? how long?

same Q for motor oil?

That greese is prolly just that greese. It was prolly a leaky gear box that someone filled with greese to permanantly lube it.

 

[two4spooky]

90 degrees i think would be easy, just hook to the 3pt and lift. I would have sprayed deisel out of a spray bottle in it or just let flat filled with deisel and then verticle again.

Your gonna get water again unless you can figure out how it got there.

Did you read the thread? 90 degrees is vertical. You are saying the three point would raise 1100lbs. cutter 8' (front to back) straight up to stand the cutter on the tail wheel after undoing the top link? Amazing, I have never seen a 3 point with quite that much lift. Still would not work though. Look at the pic, the check level plug(lowest drain point) is on the right hand side. Or your saying you can lift 6' (width) straight up buy grabbing the side of the cutter with the three point? Color me curious- take a pic and show how you do this. :thumbsup: Also the "...water again.." comment. The gear box on this cutter is VENTED. So, let's see. As the gear box heats up with use the air in the gear box heats and expands, venting through the breather. After use the gear box cools, the air contracts and sucks in outside air (read: moist or humid air, this is the South!!). After enough cycles(uses) the oil becomes fouled with water. I would guess many gear boxes are vented like this to prevent the seals from leaking prematurely. But then again the post I made above mentions the breather having failed. Both breathers, the old one that failed and the newer one with dipstick, are in the first pic also. Wheww, Man, that was a mouth full! Anyhow, off to the races!

 

[clemsonfor]

Did you read the thread? 90 degrees is vertical. You are saying the three point would raise 1100lbs. cutter 8' (front to back) straight up to stand the cutter on the tail wheel after undoing the top link? Amazing, I have never seen a 3 point with quite that much lift. Still would not work though. Look at the pic, the check level plug(lowest drain point) is on the right hand side. Or your saying you can lift 6' (width) straight up buy grabbing the side of the cutter with the three point? Color me curious- take a pic and show how you do this. :thumbsup: Also the "...water again.." comment. The gear box on this cutter is VENTED. So, let's see. As the gear box heats up with use the air in the gear box heats and expands, venting through the breather. After use the gear box cools, the air contracts and sucks in outside air (read: moist or humid air, this is the South!!). After enough cycles(uses) the oil becomes fouled with water. I would guess many gear boxes are vented like this to prevent the seals from leaking prematurely. But then again the post I made above mentions the breather having failed. Both breathers, the old one that failed and the newer one with dipstick, are in the first pic also. Wheww, Man, that was a mouth full! Anyhow, off to the races!

Yea i know what you mean and realize that i left a few words out. I meant hook the chain to the 3pt structure and lift with the FEL to verticle. I did not say that though. And as i typed it i also thought of the condensation issue of an open vented case. Get hot in the fall put up and as it cools in the 40 degree night you get condensation.