BX 1500 front axle leak

[Molerj]

Will be working on the above tractor. The leak looks to be on the front axle where the king pin goes through. Anyone have a parts list so that I could see what needs replaced, gasket, seal etc? Just from a quick inspection today, it looks like quite a few things needs to be removed to access the leak. Any help is appreciated.

 

[dex3361]

Will be working on the above tractor. The leak looks to be on the front axle where the king pin goes through. Anyone have a parts list so that I could see what needs replaced, gasket, seal etc? Just from a quick inspection today, it looks like quite a few things needs to be removed to access the leak. Any help is appreciated.

Go here and you can download a complete parts manual for the BX 1500 in PDF format.
INDEX OF KUBOTA BOOKS

 

[Molerj]

Thank you. That is more than I could have asked for. It would be great if I could find those O-rings, pn 67817-37190, at a local auto parts store. Kubota dealer is an hours drive away.

 

[bw12]

Molerj,

I bought a used BX1500 a month ago with 450 hours on it. It had the same axle pivot leak. The previous owner never used any rear ballast, and I suspect this increased the wear on the front axle pivot when using the loader.

When I took mine apart, I found a fair amount of wear on the bushings (P/N 08511-0205). Not wanting to do the job twice, I decided to replace all of the parts (shaft, bushings, o-rings, and backup rings). Removing the bushings, which are split steel and press fit, was very difficult. There was little to no access to the back side of the bushings to drive them out. It's hard to see what you are doing, and you need to keep any metal shavings from getting inside the axle. In the process of removal, I accidentally gouged the sides of the holes that the bushings fit into. Fortunately the new bushings covered the gouges.

I refilled the axle with 80W-90 gear oil instead of Super UDT. The service manual states that either is acceptable, but the gear oil is thicker and maybe less likely to leak as much.

If your leak is very slow (mine was leaking a lot), then I might try to replace just the o-rings and refill with gear oil. If you decide to replace the bushings, I suggest you make sure the seam in the new bushings are placed off to the side (as were my original bushings) when installing and not up or down, since the up/down surfaces are where all of the wear occurred.

Looking at the pivot from a design standpoint, I can see why others have been critical of Kubota's decision to have the pivot go through the oil filled portion of the axle. Having done so, they at least should have made it possible to drive out the bushings from the backside. I suspect as more BX tractors reach higher operating hours, we may see more axle pivot leaks.

By the way, my Kubota dealer let me look at their BX1500 service manual, and they even copied the relevant pages for me (I ordered the parts through them). The service manual was helpful in showing what to take apart and the tightening torques - It did not give any details of the repair or how to remove the bushings.

 

[Molerj]

bw12, thanks for your reply. I was hoping to get by with the o rings, but I guess I'll have to wait till I get it apart. What are the back-up rings & their job?. I saw them listed in the parts breakdown, but can't really tell what they are. How did you end up driving the bushings out?

 

[bw12]

The backup ring is a split ring of plastic, probably teflon, that sits behind each o-ring on each end of the axle pivot. Since the o-ring normally seals in the axle fluid, the backup ring runs dry. I think the backup ring protects the o-ring from outside contaminants (dirt, etc.) while providing a smooth low friction surface for the o-ring to rub against. The total cost for the shaft, (2) bushings, (2) o-rings, and (2) backup rings was $64, not including sales tax and a $5 freight charge. I reused the axle nut and bought a standard cotter pin.

To remove the bushings, I cut a horizontal groove in the sidewall of each bushing with a Dremel tool abrasive cutoff wheel (I stuffed a rag in the hole first to keep abrasive dust out of the axle and then vacuumed the dust out afterward). First I had to make the cutoff wheel smaller by "turning" it down (holding a grinding stone against it until it was a small enough dia. to fit in the bushing). After cutting a groove, from the backside (remember you are working through an opening on the opposite side of the axle) I drove the bushing out using a steel rod, "catching on" the groove in the bushing, while tapping the rod with a hammer.

Unfortunately I cut too deep with the Dremel tool and gouged into the housing behind the bushing. I wasn't too concerned since this is not the sealing surface, but I wish it didn't happen (a new axle housing costs $850!).

I didn't have a press, so I tapped the new bushings in using the backside of a socket and a hammer. This was a bit tricky, and a press with the proper size mandrel is really the right way to do it.

 

[Molerj]

I just finished the repair job. I replaced all the parts that bw12 did. I don't know how you did the repair with out taking the axle completely out. If just replacing the o-rings & back up rings, then removing the center bolt & dropping the axle down 6 inches or so would be easy. But to replace the bushings is a different story. I really don't think that the bushings or the bolt needed replaced, but I had the parts bought, so I went ahead and replaced them. The bushings, for others that have never done this, are pressed in against a lip, so that there is no edge to drive them out. I used a small chisel & cut a groove thru the bushing then kind of peeled them out. I couldn't have done this if I didn't take the axle out. That is really no big job. Just remove the power steering cylinder & the tie rod ends. bw12, any idea what the dealer would charge for this repair?

 

[coveredbridge]

I just had this done to my bx1500 (about 700 hrs). Dealer charged about $325, including pickup and delivery. I was expecting it to be quite a bit more, but I guess it's not all that bad if you have the right tools.

He says they see quite a few of them, and he thinks it may be because the seals may not always get properly lubricated due to the oil level in the axle and the position of the seals in the axle. I don't know if that makes sense or not.

I have the rear tires loaded, and I usually (but not always) hang my box blade on the 3ph for ballast when using the FEL. I know I've worked the loader harder that I should have sometimes and maybe overstressed the front axle, but I still think that's a lousy design with the pivot pin running through the fluid reservoir.

 

[Molerj]

I just had this done to my bx1500 (about 700 hrs). Dealer charged about $325, including pickup and delivery. I was expecting it to be quite a bit more, but I guess it's not all that bad if you have the right tools.

I charged 100.00 for labor so I guess he did alright.

He says they see quite a few of them, and he thinks it may be because the seals may not always get properly lubricated due to the oil level in the axle and the position of the seals in the axle. I don't know if that makes sense or not.

There really aren't seals. There are two o-rings, one on each side of the pin. I don't think lubrication is an issue.



,

but I still think that's a lousy design with the pivot pin running through the fluid reservoir.

I agree. Mechanic at the dealer said,"you'll be doing this again in a couple years"

 

[sw03]

Go here and you can download a complete parts manual for the BX 1500 in PDF format.
INDEX OF KUBOTA BOOKS

Yup, and so far those part number are way outdated.

My advise call a dealer and skip the free old stuff.