L3901 problem

[1sarge]

I bought a Kubota L3901 HST about a year ago with a little over 500 hrs. It is 4X4 and I started noticing the left front side steering knuckle leaking some. After reading up on it I discovered this to be a common problem with these tractors and was making preparations to replace the seal. It has a fill plug on the right side of the axle housing and a small check plug on the left side. After using the tractor for an hour or so if I remove the check plug it appears to have built up pressure in the axle housing which I think would contribute to the leak. I can find no breather anywhere on the axle. Anyone have any ideas? Thanks for any help.

 

[Blackhole49]

Don't know if it will help, but try this thread.

L Series Axle Vent

I bought this several years back and put it where I wouldn't forget it. Anyway I ran across it today and thought I better install it while it was in my hand. It fit a wide range of of L series tractors. I thought I would pass on the info, I know I'm not the only one with pressure build up in the...

www.orangetractortalks.com

 

[1sarge]

Thanks for the reply Blackhole. I will do more research about the vent.

 

[TheOldHokie]

Thanks for the reply Blackhole. I will do more research about the vent.

That vent is for older models and I dont think it fits a L3901.

I own a L3901 and I have not heard this is a problem on L01's or L02 's. Might want to ask on Orange Tractor Talks for a more informed answer. As mentiined in that old thread positive pressure was/is part of the desugn.

TOH

 

[1sarge]

That vent is for older models and I dont think it fits a L3901.

I own a L3901 and I have not heard this is a problem on L01's or L02 's. Might want to ask on Orange Tractor Talks for a more informed answer. As mentiined in that old thread positive pressure was/is part of the desugn.

TOH

Yes, the vent shown would not work on mine. Guess I will replace the seal and see what that does. Thanks

 

[TheOldHokie]

Yes, the vent shown would not work on mine. Guess I will replace the seal and see what that does. Thanks

I see you asked and got a pretty definitive answer on OTT.

L3901 4X4 axle leak help

I bought a L3901 HST last year with a little over 500 hrs on it. I have an occasional leak on the left side of front axle. Axle has check plug on left and fill pug on right side. After operating for a while if I remove the check plug it appears to have built up pressure in the housing. I see no...

www.orangetractortalks.com

TOH

 

[1sarge]

I see you asked and got a pretty definitive answer on OTT.

L3901 4X4 axle leak help

I bought a L3901 HST last year with a little over 500 hrs on it. I have an occasional leak on the left side of front axle. Axle has check plug on left and fill pug on right side. After operating for a while if I remove the check plug it appears to have built up pressure in the housing. I see no...

www.orangetractortalks.com

TOH

Yes, I think I will try the 80/90 oil because it needs changing anyway and I have the oil on hand. If still leaks will install new seal.

 

[1sarge]

I see you asked and got a pretty definitive answer on OTT.

L3901 4X4 axle leak help

I bought a L3901 HST last year with a little over 500 hrs on it. I have an occasional leak on the left side of front axle. Axle has check plug on left and fill pug on right side. After operating for a while if I remove the check plug it appears to have built up pressure in the housing. I see no...

www.orangetractortalks.com

TOH

 

[1sarge]

Yes, thanks for your help. Guess time for a new seal although I am considering trying the 80/90 first. Have the oil on hand but haven’t decided yet.

 

[DanielW]

If it's like our L4150 (I realize the 3901 is much newer, but appears to be the same design), it's a common problem due to the busing wear and thus oblong/eccentric forces on the seals. Part of the nature of how these units get used: These smaller L series are really quite small, all things considered. But also quite capable. Which results in folks (like us) putting a heck of a lot more use & abuse on the front ends than what you'd typically expect a small utility tractor of this size to handle.

Fixing it was one of the few jobs I've sent anything to the dealer for. Not because it's a hard/complex assembly. But I have too many other projects on the go, too little time, the Kubota dealer is (surprisingly) our closest dealer and their service department has a great reputation. And we're completely reliant on that tractor for feeding cattle in the winter. I wanted it sent out, fixed properly, and back as fast as possible. Didn't have time to tear into it myself between work shifts and work on it only when I had a spare hour here and there.

When they repaired it, they turned and bored the appropriate components to bring everything back centred and put oversized bushings in. Their standard procedure for these units is to get 660 bronze bushings with a thicker walls and turn them down appropriately. I asked them to send me the specs of the new bushing size, and I had new bushings made at work out of C954 - a higher-wearing aluminium-bronze alloy. Hoping by doing so (and getting a skid-steer to handle more of our loader work) I never have to fix it again.

Something to consider on yours: If the bushings/pins are worn eccentric, new seals alone might not last long.