Can oil leak from around drive shaft? (PIC)

[KYKub]

I noticed today an oil leak on my Kubota G1900 garden tractor. (Gotta love temps in the 70s on Christmas Even in KY!) I jacked up the front end and followed the leak to what appears to be the area where the drive shaft exits the motor. I tried to upload a pic, but for some reason I am unable.

The drive shaft exits the motor and connects to a triangular piece that holds the pulley that drives the fan belt. The oil appears to be coming from the area just in front (toward the engine) of the triangular piece, or where the drive shaft exits the motor.

I have had the drive shaft disconnected to replace a fan belt so I'm basically familiar with that part of the job (if, indeed, it is leaking from there). However, I have no idea how to work back toward the motor.

Is it even possible that an oil leak would occur around the drive shaft?

It's a slow leak so it seems unlikely that oil is "spewing" upward. It seems to originate around the drive shaft, but it's hard to tell exactly.

I know it's a garden tractor, but I believe the basic structure is very similar to many Kubota tractors so I'm hoping someone with more mechanical inclination than me might have some advice!

Merry Christmas, TBNers! Jeff

 

[Dave M7040]

Any time there is a rotating part originating from a housing there will be an oil seal to permit the rotation while containing the oil inside.
Often when there is a leak it is due to over filling of the engine/gearbox housing and the overfilling results in a buildup of pressure that the seal cannot contain.
Job one is to clean everything so you can be certain where the oil is coming from.
A product called Brake Clean which comes in a spray can like a big paint can works very well. It is available if auto parts stores.
I think your post should be in the lawn and garden Kubota form where someone with similar equipment may respond.

Dave M7040

 

[Looking4new]

IF you use the Brake Clean to degrease it, DO NOT breath the fumes, unless you like getting high.

 

[Dave M7040]

Another thought jkmetcalf.
Sometimes long grass, a string or piece of wire will wind itself around a shaft and get between the seal and the shaft allowing oil to leak out.
Dave M7040

 

[rScotty]

Any time there is a rotating part originating from a housing there will be an oil seal to permit the rotation while containing the oil inside.
Often when there is a leak it is due to over filling of the engine/gearbox housing and the overfilling results in a buildup of pressure that the seal cannot contain.
Job one is to clean everything so you can be certain where the oil is coming from.
A product called Brake Clean which comes in a spray can like a big paint can works very well. It is available if auto parts stores.
I think your post should be in the lawn and garden Kubota form where someone with similar equipment may respond.

Dave M7040

I'm a mechanical guy and and agree with what Dave is saying, including his suggestion about moving your question to the other forum. That way you'll be sharing ideas with owners of similar machines.

Another thing to think about is every oil-containing housing will have some sort of an external vent to allow air pressures to equalize. These vents are often findable because they tend to be capped with a rudimentary sponge or wire "crud-filter". It isn't unknown for those filters to get stopped up or plugged with dirt or chaff - or even with insects getting past the wire screen and building mud plugs in the vent tubes. If the housing can't vent it is bound to leak. So take a look for a vent next time you're poking around the leaky area.
good luck,
rScotty

 

[KYKub]

Thanks for the replies, Dave, Looking4new, and Scotty. I agree that the Lawn & Garden area might be a better place to post, but am not sure how to move a thread once posted.

Dave, the oil isn't overfilled. I have some aerosol brake cleaner and will use that to clean it up and try to pinpoint the leak. I'll be surprised if it isn't coming from the seal around the shaft, but I'll get it up off the ground enough to get a good look over the next week or so. Thanks for the tip. I didn't see any grass or debris around the shaft/seal, but will inspect that closer too.

Scotty, good suggestion about the vent. The engine is a D722, same as in my BX 1860. Here is a pic of a D722 I grabbed off the net. Would that be the vent just right of the oil fill port on top of the valve cover? If that's it, I can take the valve cover off and use a pipe cleaner to clean the vent.

The leak is fairly minor, but these things never get better with time!

Thanks again. I appreciate the feedback. Jeff

 

[Coyote machine]

Yes, seals fail for many reasons, including too dirty oil, crankcase pressure buildup, and failure by heat and wear over time. Sometimes solvents like Brakleen can be used to expand the seal in question enough that it will seal again, but usually when a seal has failed to seal completely, it needs to be replaced.
Frequent oil and filter changes can help prevent these issues, but an engine with a lot of hours and less than stellar maintenance is going to need failed/leaking seals replaced as warranted. Cleaning breathers is also a good way to prevent blown out seals due to overpressure in the crankcase.

 

[KYKub]

Thanks, Coyote. I'm not the original owner so I am unsure of what maintenance was like for most of the machine's life. By the general looks of things I doubt it was treated tenderly. I am very careful with routine maintenance, but it could be a case of too little too late. Maybe it's just a simple issue of things fail over time, especially things that move, experience friction, and drastic changes in temperature.

Anybody know if the tube on the top of the valve cover is the vent Scotty mentioned I should check?

Jeff