Leaking gearbox on 10 foot rotary cutter

[piller]

I've got an older Woods 121 pull type 10 foot rotary cutter, it works really well and I like the thing. The left hand side gearbox leaks around the bottom. I have tried putting in Lucas hub oil, that did not work. I have filled it with Coastal grease from AutoZone, that also does not work. Last week I used the cutter for a couple of days and the gearbox stayed full! I looked underneath and found a wrap of natural grass and weed stems had built up around the bottom of the gearbox and made a nice seal. The next day of mowing however removed this natural seal.

I'm looking for suggestions on how to keep this gearbox from leaking as a new gearbox will cost more than $1k. Thanks.

 

[RedNeckRacin]

Get a replacement seal and replace it. I think the seals are only about 20-50 dollars. I did one in my MX10 and it took some work to get the stump jumper and hub off but after that, the seal was a piece of cake. The nut needed to be re torqued to around 600ftlbs though!!

 

[MORRISONSTEEL]

I agree, fix the seal before damaging the case. But if not wanting to repair you may also try corn head grease from an ag dealer.

 

[Xfaxman]

If you don't about corn head grease, click this thread: http://www.tractorbynet.com/forums/attachments/271324-grease-rotary-cutter-gear-box.html

 

[piller]

If you don't about corn head grease, click this thread: http://www.tractorbynet.com/forums/attachments/271324-grease-rotary-cutter-gear-box.html

Thanks for the link! I'll see if I can get some corn head grease and give that a try.

 

[GManBart]

I can see using heavier grease to get through a couple of days, but risking a $1000 part because of a $20 seal doesn't make much sense to me.

 

[Xfaxman]

I can see using heavier grease to get through a couple of days, but risking a $1000 part because of a $20 seal doesn't make much sense to me.

It is not heavier, it is thixotropic.

 

[GManBart]

It is not heavier, it is thixotropic.

Do you know what he was using before to know which is heavier?

It's certainly thicker (NLGI 0) when it's at rest. I'm not sure if they publish what grade equivalent it is when it's being worked.

Regardless, changing oil/grease isn't a substitute for replacing a worn seal.

 

[Navasot]

meh.... iv seen mower seals go out in the first few years and then run the rest of its life on Hightemp grease..

still pretty simple and cheap to fix the leak though if you do it yourself

 

[RDrancher]

If you don't about corn head grease, click this thread: http://www.tractorbynet.com/forums/attachments/271324-grease-rotary-cutter-gear-box.html

Corn grease works great. I used it on a final drive for quite awhile before a hydraulic hose blew. The final drive had to be removed to replace the hose so I bought a rebuilt final and replaced it while it was apart. Several times I compared the temps on the corn head final and the one containing the correct oil. The corn head grease ran cooler every time. I tried thicker oil and Lucas Hub oil. Both leaked really bad.

I use corn head grease now in my brush hog gearbox.