Close call changing front diff. oil

[PlanMan]

Thought I would share my experience for safety's sake:

I bought a used Kubota with low hrs. and was changing all fluids/filters etc.

The tractor was not overly hot, I pulled it out of the garage & let it idle in the driveway for about 10 minutes.

While removing the drain plug on the front differential, as it neared the last thread, it suddenly blew out, hit the tire, & shot gear oil out for a distance of 5 ft. from the tractor, soaking my arm and my driveway. I feel fortunate not to have taken it in the face / eyes.

I attribute it to the previous owner over-filling the differential and possibly using an oil that foamed, adding to the condition, but please advise if anyone knows what else might have caused this.

 

[RobJ]

WOW!! Never heard of that before. Usually the seals and plugs would leak if there was that much pressure. I don't think that unit is connected to the engine either.

Wonder what happened to. At least you know the oil seals are in good shape.

Was there foam in the oil?

 

[Bird]

I'm really not familiar with your model Kubota, but mine had short curved vent tubes on top of the front axle, so I would assume yours does, too, and that the vent is plugged and needs to be cleaned out.

 

[Egon]

Just curious, was the outside of the differential or the plug hot?

 

[PlanMan]

RobJ, Egon, & Bird,

Thanks for the replies -

1. Neither the differential nor the plug were hot. I let the machine idle up to temp in the driveway and had not used it.

2. No discoloration in the oil, dark gray/black. No water.

3. Bird, I checked my owners manual and parts manual. No vent on this unit. I have a friend who teaches heavy equipment repair and that's the first thing he said also - the vent's plugged. It's a 1990. I'll post a pic.

Just thought it was worth posting so someone else might keep it in mind if they have an older machine without vents.

 

[Doc_Bob]

While removing the drain plug on the front differential, as it neared the last thread, it suddenly blew out, hit the tire, & shot gear oil out for a distance of 5 ft. from the tractor, soaking my arm and my driveway. I feel fortunate not to have taken it in the face / eyes.

I always wear glasses when working on my tractor. Always.
Thank goodness you were not injured.
Bob

 

[Bedlam]

I have a ford tractor with four wheel drive. It also has no vent. And I have replaced seals etc. before. But the filler/dip stick, would build pressure and push the oil past the sealed.
I replaced the filler?dip plug with a piece of PVC pipe and a cap. (1/2 inch cpvc)..The 1/2 inch threads almost fit, but they would fit tight enough to seal.I drilled several small holes int he side of the cap to let it vent.
Haven't had any pressure pushing the oil past since.
I just Carry the original plug, and use it when checking the oil level.
But if your not having the seals leak, perhaps you shouldnt "vent" it.

 

[Bird]

No vent on this unit.

I think Bedlam had the right idea. I'd be making a vent for it one way or another before I had to replace seals.