Leaky front axle

[jeffgreef]

My 2003 L3430 4wd leaks a bit of 80/90 at the turning joint for the right wheel, not the left. Enough leaks to wet the inside of the tire a bit but not a lot. I jacked the front end up and shook the wheel and the joint has only the slightest detectable play. Checked fluid level and it only needed 1/2 quart.

Seems like a simple leaky seal. Have you seen this before on these models? Is the seal hard to replace? Think it's minor and can be ignored?

The left does leak just enough to wet the surrounding metal and collect dirt.

Thanks for thoughts.

 

[Hay Dude]

It’s a faulty seal. I have replaced 3 of them on my Kubotas. I find it usually happens with a lot of heavy loader work, but that’s just speculation. A leaky seal won’t really hurt anything unless you immerse the leaky area under water (if oil can leak out, water can leak in). If you get water in the bevel axle case, that could be bad.
Otherwise you’re not hurting anything, but you have to keep checking the axle oil level. You don’t want to run it dry.
It’s repairable with decent level of mechanical ability. Take A look at your bearings while you’re in there.

 

[jeffgreef]

That's pretty much what I figured, Hay Dude. Thanks for your input.

 

[Hay Dude]

Does it look like this?

You have plenty of time to fix it. Just remember it could turn into a "gusher" at some point and you could lose oil faster. I suggest a daily inspection.

 

[amhicks21]

Ive replaced quite a few of those seals as well as the bearings. Its not just a usual failure, its practically inevitable in my experience. They arent hard to replace and dont require any special tools other than a good set of snap ring pliers. The biggest thing is to keep everything spotlessly clean when you start pulling things apart. the bores that the bearings sit in have pretty tight tolerances so if you get even a single grain of sand stuck between the bearing and the bore it wont want to go back together. from what ive heard and seen personally, the usual cause of those leaking is moisture causing a little rust against the seal surface causing the seal to wear out along with dirt. When you fill the fluid back up, expect it to take quite a while to work its way through all the bearings so give it plenty of time before you check it and top it off the final time. In some cases, a seeping seal can be a sign of bearings starting to fail so have a good look at the fluid when you drain it to make sure its not shiny.

 

[Hay Dude]

Ive replaced quite a few of those seals as well as the bearings. Its not just a usual failure, its practically inevitable in my experience. They arent hard to replace and dont require any special tools other than a good set of snap ring pliers. The biggest thing is to keep everything spotlessly clean when you start pulling things apart. the bores that the bearings sit in have pretty tight tolerances so if you get even a single grain of sand stuck between the bearing and the bore it wont want to go back together. from what ive heard and seen personally, the usual cause of those leaking is moisture causing a little rust against the seal surface causing the seal to wear out along with dirt. When you fill the fluid back up, expect it to take quite a while to work its way through all the bearings so give it plenty of time before you check it and top it off the final time. In some cases, a seeping seal can be a sign of bearings starting to fail so have a good look at the fluid when you drain it to make sure its not shiny.

I had one side with a failed bearing, too. The other side had a perfectly good bearing.

 

[rScotty]

It's one of those jobs that needs photos, an absolutely clean place to lay out the parts, and be sure to keep all the shims in the right order. A few notes wouldn't hurt.

Like Hay Dude says , I also wouldn't replace a bearing just to do so. Check them out.
I also don't mind putting up with a small leak for a long time and just check the oil in the axle daily instead of replacing the seal. It's a job you can schedule for convenience.

If you do replace a bearing, do not be tempted to replace an open face bearing with a sealed bearing. They need to be open for oil to flow through.

If the shims stay in order it is not a hard job. It is a moderately fussy job, but clean work and kinda fun to see all those shiny surfaces. You can do a lot of it sitting down.
And it sure beats doing a rear axle seal.
Good Luck,
rScotty

 

[jeffgreef]

Thanks all. I'm going to wait and see. Tractor doesnt get a lot of use to begin with. I'm willing to tolerate a small leak for a long time and wait to fix until I'm bored enough looking for something to do.

 

[ptsg]

In the mean time, you can check online for some videos to get familiar with the job in hand. Doesn't necessarily needs to be a Kubota video, these front axles are very similar across most brands anyway. You'll find videos for the wheel seals and for the knuckle seals.

 

[5030]

All the above plus you need to have a look-see at the king pin and king pin bushings, especially if you do a lot of loader work. Easy to replace as well. drive them out with a suitable sized drift and drive the new ones in.

For some reason (I suspect manufacturing cost), Kubota likes to use ball bearings in the outboards instead of Tapered rollers which do0a lot better job of bearing the weight imposed by a front end loader, because tapered rollers distribute the weight a lot better and have a wider contact point than ball bearings.

If you king pin bushings get worn, that will cause the radial seal to leak as well. Just replaced the left side on my 6000 hour M9. Easy to tell too. Loft the front end, taske the wheel off and grasp the outer flange and try to move it vertically. If it moves at all it can be the bushings, or the king pin or both. Good time to check the front axle pivot too for excessive slop. It needs to move free in an arc with no lateral movement. Owners tend to forget about greasing the pivot and checking the pre load. Your owners manual details how to set it using the front bolt and jam nut.

 

[LD1]

I just had to do one on my MX a few months ago. Dealer stocked the seals because there are alot of the tractors that share the same axle and its a pretty common thing. Bout $80 for a seal and about an hour to do.

There are some good you-tube videos so you know what you are getting into. Clean the area good first so you dont end up with a bunch of dirt contaminating the area. Then when you jack it up and take the wheel off....let the axle pivot to the other side so you are working on the high side, and you wont loose hardly any oil

 

[Hay Dude]

I like the Kubota “bevel axle“ design, but it is more complex and prone to failure than a simple u-joint front axle
Kind of like the Humvee H-1 gear reduction front axles. Really cool design to increase ground clearance, but costly to fix.

 

[LD1]

I like the Kubota “bevel axle“ design, but it is more complex and prone to failure than a simple u-joint front axle
Kind of like the Humvee H-1 gear reduction front axles. Really cool design to increase ground clearance, but costly to fix.

Do any modern compact tractors use a simple straight u-joint axle? All the ones I ever see are of similar design to kubota

 

[Hay Dude]

Do any modern compact tractors use a simple straight u-joint axle? All the ones I ever see are of similar design to kubota

I think the older ones might???
I have bigger Kubotas and my bigger other brands have straight axles

 

[ptsg]

The first and smallest tractors that comes to my mind right away with straight U joint axle and planetary hubs is the Fiat or New Holland 35-66 and the Agrifull 35. Not sure if those fit on the modern category though.

Oh and the isodiametric tractors, the ones that have front steering instead of being articulated, also use straight axles with U joints.

 

[Smokeydog]

Would not want a tractor with front axle U-joints. Don’t even like them on my trucks. Puts a huge strain on driveline components and loss of traction with non constant velocity rotation.

1965 Dodge W300 has smooth manual steering lock to lock.

Bevel gears is about the only way to get high angle steering articulation.

 

[arto98607]

My 2003 L3430 4wd leaks a bit of 80/90 at the turning joint for the right wheel, not the left. Enough leaks to wet the inside of the tire a bit but not a lot. I jacked the front end up and shook the wheel and the joint has only the slightest detectable play. Checked fluid level and it only needed 1/2 quart.

Seems like a simple leaky seal. Have you seen this before on these models? Is the seal hard to replace? Think it's minor and can be ignored?

The left does leak just enough to wet the surrounding metal and collect dirt.

Thanks for thoughts.

Are those front axles vented, or are they non-vented like the one in my Ford 1310 was?

Mine was obviously building up some pressure when the axle gear oil etc. was getting warm from use and it leaked some oil from the seal on one side.

My (temporary) solution was to make a new dipstick with a vent, but I realize this is likely a temporary solution and the seal(s) will eventually have to be replaced but so far so good and there are no visible leaks now about year and half later!

New dipstick with JD 5801 vent installed:

 

[bdhsfz6]

My 2003 L3430 4wd leaks a bit of 80/90 at the turning joint for the right wheel, not the left. Enough leaks to wet the inside of the tire a bit but not a lot. I jacked the front end up and shook the wheel and the joint has only the slightest detectable play. Checked fluid level and it only needed 1/2 quart.

Seems like a simple leaky seal. Have you seen this before on these models? Is the seal hard to replace? Think it's minor and can be ignored?

The left does leak just enough to wet the surrounding metal and collect dirt.

Thanks for thoughts.

Same tractor, same problem. The right side seal started leaking UDT2 fluid at around 200 hours. I switched to 80/90 gear oil which stopped the leak. At 350 hours, it started leaking the 80/90 so I switched to 85/140 and the leak again stopped. I traded the tractor 2 years later at 550 hours and the leak hadn't returned. I was honest when I traded the tractor and told the dealer about the problem. He just shrugged and said "common problem".

All along, I figured I'd have to replace the seals at some point but the heavier oil solved the issue. I don't know how much longer it would have lasted though.

 

[Smokeydog]

Like your vent. Venting the axle is a good point. My 80s era M5030 front axle was leaking some. Especially after bush hogging or transporting trees/brush. Hillside farm you stay in 4wd. Didn’t have a dipstick, only fill and fluid level plugs. Made vent tubing filter/plug for the fill port. No more leaks for 20 years till I sold it.

Newer tractors have plastic dipstick plug. Not sure how or if they vent. Do the newer tractors front axles have a vent?

 

[Locoweed]

Just for general info. I tried some seals off from Ebay that were about a third of the kubota price. Worked ok for a couple of months, then started leaking.