L2850 Front Axle leak and repair question

[Keppie]

I am a newbie to Kubota tractors. After running my newly acquired L2850 in 4WD for maybe 20 minutes on my hilly property, I parked and shut it down on the driveway and went inside my garage. I came out a few minutes later and was greeted by a hemorrhage of oil that leaked (erupted) from the front axle case. The picture of the oil on the cardboard was taken a few minutes after discovery (more oil was under the cardboard).

I obtained the Workshop manual (L2250-L2550, L2850) and the Illustrated Parts List. I took pictures of the oil leak to the local dealer who thinks the leak was caused by a failed oil seal (PN 31353-4387-0) between the Bevel Gear case and the Front Axle case. He sold me the Oil Seal Kit, an O ring, and a Plug. Funny he didn稚 say anything about the creamy appearance of the oil that leaked. It is supposed to be 80-90W gear oil. Some of it looked like gear oil but most of it looked like a lighter viscosity amber fluid?ome portion of the spill looked creamy?.like maybe water got inside the housing and mixed with the oil. Anyway?

It looks to me that the only way to remove and replace this oil seal is to separate the Bevel Gear case housing from the Front Axle case. According to the instructions and pictures in the Workshop manual on page S.6-12, that separation looks a bit scary for someone that hasn't done it before.

For those of you that have done this seal replacement (or knew enough not to attempt it), I need to know whether it is something that I can handle or is this best left to a trained specialist? The two steps that concern me most are (from the Workshop manual, page S.6-12):
4. Tap out the 12T bevel gear (6) and ball bearing, and
5. Draw out the bevel gear shaft (7)

How difficult is it to tap out the 12 T bevel gear and ball bearing race? The illustration shows the mechanic using what looks to be a long drift up against the gear being hammered by a large ball peen hammer?and the angle of the drift looks more like it is being used as a lever.

Any comments? Like,"all it takes is a few light taps and it all comes apart nice and easy?" or, "getting the gears out is tough but removing the snap rings is darn near impossible"

Step (5) says to draw out the shaft. How does one draw out the shaft? With the plug, retaining clip, and shim removed from the lower end of the axle case, does the bevel gear and ball bearing just slide off the end of the shaft and fall out the end of the case (after being hammered on)? Isn't the shaft is still engaged into the upper bevel gear housing. Is a tool required to grip and pull the bevel gear shaft out? What tool is recommended to avoid damaging the splines or marring the shaft? Should the shaft come out easily or are there circumstances where dealer only special tools and skills are required to get the shaft out? (yes, it has occurred to me, too, that I have been shafted )

Since the axle case and bevel gear case come off as a unit, I am considering taking the whole works to the dealer as opposed to tearing into it myself. However, I have lots of automotive tools and can turn a pretty good wrench and I am on a very limited retiree budget. Straightforward opinions are invited. This fool is too old to rush in Thanks in advance.[/SIZE][/FONT]

 

[n6ckv]

I have an L3450 that had a similar leak. I had a local mechanic come by to fix it. I was at work so I did not watch him. It was about 4 hous of labor and $75 for parts from Kubota

carl

 

[rbargeron]

I respect your caution - but my bet is you can handle this job just fine. There is a good axle seal replacement discussion here that is based on the somewhat larger Grand L axle - but Kubota's methods and fits are very similar across the product line. The "tapping out" of various parts can be done with improvised tools - your mechanical experience will prevail. Have fun - and let us know how it went. Take care, Dick B

 

[theboman]

Got a B7500 and had the exact same thing happen. I think it was around $75 to get it fixed at the tractor store (Davis Equipment, GREAT FOLKS!).

I think the seals are the achelies heel. Heavy loader loads seems to be the problem. I have another one dripping as I type.

 

[Keppie]

OK Randall, thanks for that link to that thread....I don't know why I didn't find it when searching but I am very happy you sent it along.

After reading , I am going to give it a go.

There was other useful information in that thread, as well. My front wheels are reversed because the fellow I bought it from had the same kind of hilly property I have. Nothing is level so a wider stance helps with stability when sideways on a hill. I didn't think about the consequences of having a widened stance on those axles. Also, what is a "reasonable" weight to pick up with the FEL? After reading the comments about the extra stress on the front axles with heavy FEL loads (plus the reversed wheels), I remembered what I had last done prior to the axle leak in the picture. I had just purchased a box scraper which I brought home on my trailer. So I attached chains to the FEL and lifted the box scraper off the trailer and used the tractor to move the box scraper about 100 feet to where I set it down. My guess is that the BS weighs about 300 pounds. Would that be enough weight (out at the end of the FEL) to create the stress on the front axle to cause that seal to puke as it did? No leaking occurred (clean driveway) until the tractor was parked and shut down.

 

[rbargeron]

...... My guess is that the BS weighs about 300 pounds. Would that be enough weight (out at the end of the FEL) to create the stress on the front axle to cause that seal to puke as it did? .........

Lifting that much load should be fine - IF the bearings and seals are in good shape. But when the seals start leaking, they let water in - which wrecks the bearings and floats the oil out. The oil leaks until it is below the seal level - then when the tractor does a little work the axle warms up, the oil/water expands, and it pukes out through the already damaged seal. It probably leaked when it was getting regular use, but with the long lay-up it dried off. Bet you'll find some pitted bearings in there. Kubota sells ball bearings pretty cheap so replace any that are rough or stained black. After the repair you won't need to worry about heavy loads damaging it. If the loader can lift it, the axle should carry it around without springing a leak.

 

[dfkrug]

Since the axle case and bevel gear case come off as a unit, I am considering taking the whole works to the dealer as opposed to tearing into it myself. However, I have lots of automotive tools and can turn a pretty good wrench and I am on a very limited retiree budget.

I have replaced the seals in my front axle for the L2550DT, which is exactly
the same as the L2850. It is easy, so I do suggest you try it. The two
special tools I needed are a pickle fork for the tie rod end, and a snap ring
pliers with 90-deg ends. Kubota has a retrofit (better) seal for that
tractor as I recall. There is another thread or 2 on TBN about this Kubota's
axle.

Your oil looks real bad, so it needs to be flushed and replaced with gear oil.
I also found that I could minimize the leaking by keeping good weight on
the front axle while stored.

 

[Keppie]

Thanks for the picture and encouragement. The operation will likely take place later this week and a full report will be forthcoming.

 

[fxrupr]

Same problem as I've had. I'm looking at my 2nd axle seal replacement on a Kubota B7500 HST I bought new in 2000. I do all my work myself because what I have found is that the so called mechanics who work on this stuff often as not if they work for a dealer will sell you new parts if they possibly can or replace one thing and not fix the root cause. I have put 2 seals in my hydraulic pump and neither of them held for more than a couple of months, but a new pump from Kubota is over $700 dollars and it would probably leak to.

The first time I fixed the axle leak, the machine had less than 200 hours on it. I replaced both final drive castings, because they were deformed and the bearings just slapped around in the bores. Terrible engineering and soft aluminum is the wrong material to use in a high stress envirenment like the front spindles. I use the loader a lot and they shouldn't market a tractor with a "custom fit Loader" unless it can take the stain. I am hoping they will go to a cast iron spindel for the next replacement but I won't hold my breath.

Other that the axle leaks and the hydraulic pump seal dumping hydraulic oil into the engine I've used the heck out of the little guy. I think somebody decided to poor boy those 2 areas and it sure shows. I just have to keep checking my oil to make sure it's not to full!

Hey will any of the bigger tractors axles fit the B7500? Are they aluminum or cast iron?

 

[seanrogers998]

As you said you are a newbie, but still you think that solving the problem by yourself is the key...