MMM Gear box vent?

[Abe]

I have an L2250 with a RC60 25 MMM. I cut about 2 acres of grass with it during the season; weekly, sometimes bi weekly. My question for those that are in the know; is the gearbox on this deck supposed to be vented? If so where would the venting be? Ive had the gearbox in the repair shop several times at my local Kubota dealer because it keeps losing oil out of the PTO shaft area, repair of a new seal seems to last a year or so and then back for repair again. Last week I brought it to a local machine/welding shop for repair and he tells me there is no venting on it, which he thought was rather strange. The seal did not seem to be the problem, but rather the collar that goes between the seal and the PTO shaft. It seems like the pressure buildup inside the gearbox is pushing the collar out to the point that the oil can seep out where the splines on the PTO shaft start. He was debating with me how and where would be a good place to manufacture a vent for it?

Abe.

 

[ThisIsNotaStep]

Hi Abe
If the seal keeps going are any of the mating surfaces scarred, worn? I just did a seal on a BX and for the life of me couldn't see if what was left on the shaft was a milled step, or an old dust cover. Took allot of convincing the hack it off with vice grips, but glad I did. I think previous services just left the old one on 'cause it was too difficult to remove.

 

[D2Cat]

Often times a gearbox will have a hole in the fill plug as a vent. Some plugs have a mesh type material in the hole to keep dirt out. If you need to you can take the plug out and drill a small hole through the top, might put a small cotter pin in it to keep it open. (be sure to bend the ends before screwing on)

 

[North Idaho Wolfman]

Replace the collar and seal as most likely it's gotten hot and stretched or worn.
Also put some thread lock on the collar to hold it in place, because the shaft probably has some wear on it too.

Also fill the case with Corn Head grease instead of oil and you'll be golden!

 

[Abe]

Thanks for the quick replies guys. I am hoping to hear back from my repair man very soon; haven't cut the grass now since over 2 weeks ago. I will soon have to look for a baler if I can't get back to cutting.

 

[Diydave]

A vent plug costs like 2 bucks, so try it...

Put as high up, as you can, on the gear box or cover...

Take care in drilling, and tapping, you don't want to cause clearance issues...

http://www.surpluscenter.com/Brands/Prince-Mfg/1-4-NPT-BRONZE-BREATHER-9-4195-4.axd

 

[100 td]

This thread clearly shows a vent on the box, does yours have something similar?
http://www.orangetractortalks.com/forums/showthread.php?t=25035

 

[North Idaho Wolfman]

This thread clearly shows a vent on the box, does yours have something similar?
http://www.orangetractortalks.com/forums/showthread.php?t=25035

No it's not the same, not all mower decks are built the same, Especially one that is 30 to 35 years old compared to one that is 1 year old.

 

[100 td]

does yours have something similar?

not all mower decks are built the same,

But they realistically do the same job, and the physics of expanding oil and air when heated hasn't changed, perhaps a similar vented plug could be used or drill or thread a vent into the housing.
The Chinese built many posthole diggers without a vent on the gearbox which spewed oil out past the seals until they finally worked out the science and installed a vent plug!