LS 4330 FRONT AXLE SEAL Need diagram

[randy Wright]

The lower gear seems to be made that way. It does have a couple of very minor abrasions on 3 teeth. Heavy outer gear seems to be fine. The only damage I see... is to teeth on spline shaft/hub (my finger pointing at) You say that is probably ok as long as snap ring goes on?

I ordered the 5 parts in diagram for a total of about $68.00 from tractorsmart off the pdf parts diagrams they sent me for my tractor.

Can someone give me the steps of reassembly. Ie snap ring keeper seal . I have not inspected it real carefully. Does the bearing come out toward the tractor. Since it was totally blown out I dont see how it was put together.

Thanks for all the help.

 

[rbargeron]

The diagram below is from an earlier grand L - the assembly is similar,except on yours the axle seal B mounts inside the 12-bolt case cover 10. Actually the groove your finger points to in the picture is where the two half-circle keepers 11go. You may have thought they were broken but they may not be.

I believe the order of assembly would be to (1) install the seal, shim, and outer bearing in the cover - parts 200,210 and 220 in your diagram. The new seal may have an inner sleeve that installs separately on the axle (typical of Kubota) (2) slide the axle thru the seal and bearing, (3) place the two half-circle keepers - parts 190 on your diagram - in the groove - a little grease will help keep them in place during assembly, (4) slide the large gear onto the axle and over the keepers, (5) slip the inner bearing and shim - 160, 170 - over the end of the axle. (6) clean the case surface and install a new o-ring or apply some sealant (7) then place the axle/cover assembly over the two studs and slide it all together.

BTW - as always, prompt cheerful refund if info turns out to be bogus. Take care, Dick B

 

[randy Wright]

looks ok except for one part. The inner bearing and shim did not come out
with axle front and bevel gear. Do I need to remove them?

Awaiting parts.
thanks again great help for a new tractor owner!

 

[rbargeron]

It would be good to flush the fine debris out of the bearing - could do it in place I guess, It has taken some wedging load so it could be damaged. On the other hand it is well supported so may be ok. If it feels the slightest bit rough I'd call Ronnie and ask him to add it to the order - cheap insurance.

 

[dfkrug]

I've found a couple things about Kubota parts - usually the bearings are NOT pressed in place - they fit very close but you can remove/install with light force.

That has been my experience too. So that inner bearing should be easy
to remove. I definitely like that feature of Kubotas.

I just pulled apart my JD4300 hub and it did take a press to get it apart.
I am happy with how big the bearings are, however.....bigger than any
hub bearings I have seen on L Kubotas. AND the inner hub bearing is a
non-tapered roller bearing.

 

[Farmerford]

R Bargeron:

I appreciate your knowledge almost as much as Randy. I have an L4330 and will file this thread away for future reference.

Can you help me understand how the bearing was damaged? If Randy was moving the rear end of the tractor with the backhoe, by lifting the rear wheels off the ground, is it possible that he could have put enough weight on the front wheel to crush the bearing inner race? Unless he lifted the rear end several feet into the air, wouldn't the weight on the front wheels be about the same as when the tractor sits level. Even if there were a substantial increase in weight on the front wheel, it doesn't seem like it would be more that the 2500 + pounds from the FEL that the machine is supposed to tolerate?

I understand your explanation of how the seals leak, water gets in, etc. But how is the seal damaged in the first place? Do you think the axle flexes enough to damage the seal without destroying the bearing? Or is there perhaps some sideways (axial) force that damages the ball bearing? Seems like all the outward axial force would fall on the outer bearing and all the inward axial force would fall on the inner bearing. I understand that most ball bearings do not tolerate a large radial load.

I am particularly interested because I have a B2400, L2900, and L4330 that all carry heavy loads in their FELs much of the time. I wonder if some particular maneuver that I do puts the same sort of stress on the front wheels that Randy's did. Is it overkill to consider replacing the bearings every 500-1000 hours to avoid permanent damage to the axle and gears, or can that damage be avoided if the tractor is not moved once a substantial oil leak is spotted.

Didn't mean to ramble, but any thoughts you have will be greatly appreciated.

 

[repete]

I have replaced MANY front axle parts on my well used L2550 (5000 hard hours). I have replaced both outer housings for cracks, wheel seals more times than I can count, internal bearings and the large two piece seals on top.

These were very common repairs until I returned to front wheels to the "narrow" setting. I had reversed them to get them as wide as the rears for loading onto a trailer.

After having returned them to the narrow setup, I have had no problems. Expensive way to learn that the bearings and housings are loaded way differently with wheels reversed.

The diagram is very useful. Not until I examined the same picture a couple years ago did I realize how the center line of the wheel in the narrow position was aligned with the bearings providing equal loading. With the wheels reversed the load is greatly increased on the outer bearing and transferred to the $$$$ outer housing.

If you have a leak that appears to be the wheel seal and it does no go away with a new seal, suspect a hairline crack in the outer housing.

I can tear this differential down with my eyes closed...

 

[kevinj]

This is my third try to load pictures I reduced them from size.

Worked this time

first diagram showing destroyed parts.
second cleaned up ready to take apart
3rddamage to spline hub
last two destroyed bearing and shredded parts.

I would pull the whole outer housing apart so you can get to the bearing under the pinion.

 

[rbargeron]

Can you help me understand how the bearing was damaged?......... Even if there were a substantial increase in weight on the front wheel, it doesn't seem like it would be more than.....the machine is supposed to tolerate?

......how is the seal damaged in the first place? .

Good questions - don't know that I have solid answers but I've always thought that the upper seal A is oriented so that the dirt and water sit on top of the interface and eventually find their way in, starting the downhill road to failure. The other theory I have about bearings is that they all have microscopic imperfections in them just waiting for the random event to be lined up in contact when the force is momentarily huge.

It isn't clear if the load was axial or radial or both when Randy's outer bearing gave it up. If the bearing was perfect, you'd expect the housing to break first - but if it already had a weak spot some extra loading could finish it off.

Ball bearings are versatile in machine design because, unlike tapered roller bearings, they support axial loads in both directions. All that's needed is some snap rings to keep everything assembled. But ball bearings have "point" contact (actually a small puddle of contact) and stresses are high.

I don't think there's much a tractor owner can (or should) do in anticipation of bearing or seal failures - if it happens, it happens. The damage usually doesn't extend too far. Sorry I can't offer a more satisfying theory. - Dick B

 

[dfkrug]

After having returned them to the narrow setup, I have had no problems. Expensive way to learn that the bearings and housings are loaded way differently with wheels reversed.

That is an excellent point, REPETE.

I also found the L2550DT hub repair to be fairly easy. The last one I
did was years ago, but Kubota had an updated seal design that was
supposed to exclude dirt better. I will bet that if you drive your tractor
hub-deep in mud, you will force dirt into the seal(s) on many tractors.
I have also had a tractor that got some fishing line into the seal, which
was invisible until dissassembled.

As for the 2 ball bearings in there, I think that a move to roller
bearings is a good idea.....I wonder if the latest Grand L40s do that.