Bent rear axle. Options?

[timebak]

Just over two weeks ago I bought a well-used BX2230 with 1500 hours. It was all I could afford, and I bought it "where is, as is". I've bought several used tractors over the years, so this ain't my first rodeo. Anyway, two days ago I noticed when mowing the one very small flat area of my yard that the left side of the cut varied up and down somewhat, or so it seemed. This afternoon I dropped the deck so that I could give it a thorough servicing and decided to check out everything under the belly of the tractor. The brakes needed adjusting so I had the tractor up on the lift to give me more working room, and I spun the rear wheels by hand.

I noticed the left rear wobbling quite a bit. But I wasn't too concerned because I thought it was probably a warped wheel, but it got to eating at me, so out comes the impact wrench and off comes the wheel. I spun the right side and watched the left side and the dang left axle is bent. Measuring off the top flange of the hub, it's got a total of 0.282" of runout in it, which equates to 0.141" of warpage in the axle.

The way I see it, I've got three options:
1). Take it to a dealer and let them fix it, which probably means a transaxle teardown and replacement of the axle. I have no idea what that might cost. If anyone can give me a swag on that, I'd like to hear it.

2). Tear it down and fix it myself, replacing the bent axle. Again, I have no idea what parts might cost or how difficult that might be. I've rebuilt quite a few engines, a couple of automotive transmissions, have plenty of tools, a cool garage to do it in, and I have a shop manual for the tractor.

3). Try to straighten the axle myself without tearing down the transaxle. My initial idea would be to set the axle down on a heavy duty jack stand placed up close to the outboard end of the transaxle housing, next to the outer oil seal. Rotate the axle so that the warpage is upwards (the maximum displacement of the flange is at the highest vertical point). The jack stand would serve as a fulcrum to greatly reduce the load on the transaxle housing while bending the axle/hub downward. To bend the axle, I'd make a tool by fabricating a heavy "hub" plate that has the wheel lug hole pattern in it, then weld a stout pipe or beam to the fabricated hub plate, plano-perpendicular to the plate. Then bolt the hub-plate of the tool to the axle hub with the lug bolts (or regular hex bolts with the proper thread pitch and diameter). Then, with the warpage upwards, and the axle stand in place as a fulcrum, push downwards on the end of the pipe or beam "handle" of the tool and, if all goes well, I might be able straighten the axle sufficiently without snapping it off or fracturing the transaxle housing. Any ideas if this might work?

I'm open to suggestions, and I'd really like to hear from folks that have really been into some of the BX and small sized Kubota transaxles and have BTDT.

Also, I noticed when I got the deck off, that both the left side and right side deck lift latches and linkage have been welded on. And the deck appears newer than the tractor. I'm wondering if this tractor didn't fall off a trailer going down the highway.

Thanks in advance for your help.

Tim

 

[timebak]

Well, I see that ordering from Messicks that I can get a new axle for a little over $200. I guess that's somewhat encouraging.

 

[KennyV]

Considering that the axle is not 'too pricey'... and that you appear to be lucky that the axle housing was not already cracked... I think I would leave well enough alone and replace the axle, sounds like you have the tools, shop & enough know how... Post pictures, everyone likes seeing inside tractors... KennyV

 

[LD1]

I agree. Just replace it. I would be afraid of damaging the housing trying to straighten it. And it would likely just bend again if not break.

 

[haveissues]

I suspect if you try to straighten it on the tractor you will end up with more broken and a axle that is still bent. I would either replace it or take it out and try to straighten it on a press, depending on where it is bent.

 

[Jim Nelson]

I agree with replace it.A year or so ago I had to repair the dif lock on my B7800 and was pretty intimidated until I got into it.You will find that it is easier than you probably think and a whole lot cheaper than paying a dealer.We're really fortunate to have Messick"s for parts.

 

[rbargeron]

I agree trying to straighten in place puts the housing at risk. I would take the axle out and straighten it with a press. The diagram implies that if you pry out the side seal there's a circlip holding the bearing and axle in the housing. It will require draining the case. As always, prompt cheerful refund if info is bogus. Good luck,

 

[like2wheel]

As far as the deck goes, I know on the earlier BX's the mounts were inside the arms & on the later models (I think it started with the 50 series) they were on the outside.
I've heard of others who welded the arms or mounts to fit a deck on a different series.

 

[tjkubota93]

If you have rebuilt an automotive transmission I am sure you will be ok.
It doesn't help you, but I sure would like to see some pictures of the insides.

 

[timebak]

Called two different Kubota dealers. One said the transaxle absolutely HAD to come out and that one of the circlips that released the axle was up inside the differential carrier assembly. The other dealer said that all you did was pry out the axle oil seal, release the external circlip in the end of the axle housing and then tap on the inside of the flange or use a slide hammer and the axle and bearing would come right out. Both said that they had never heard of anyone bending an axle on a BX2230. They both said it wouldn't surprise them if that axle was that way from the factory, because any force that could bend that axle should have broken the transaxle housing as well.

So now I don't know what to do. If I pry out the oil seal, I'm committed, because there ain't no way of getting an oil seal out without ruining it. If the axle won't come out, then I've GOT to pull the transaxle assembly and tear it down before I can use the tractor again. If I HAVE to pull and tear down the transaxle, then I want to wait until after mowing season.

Another thing I found was the front boot is completely gone off the driveshaft and the HST cooling fan is missing two blades. So I'm going to have to pull off the seat/floorpan/fender assembly and pull the driveshaft out and refurbish it. I'm gonna have to do that right away, so I don't ruin the end of the driveshaft from dirt getting up inside that front CV joint.

By the way, thanks to all of you who have responded. I'm still looking for definitive answers, so if anyone knows for sure how those axles come out I'd really, really like to know.


Tim

 

[ovrszd]

It appears you have already been given the answer as to how it comes apart. Trying to straighten it in place is a disaster in the making. I've tried straightening things like this with my 50 ton press. Just before you get it straight, it'll explode into two pieces. While I was there I'd replace the axle seal along with the new shaft. I think you now know why the ad was "as is".

 

[RoMad]

Since you have to take it apart to change the axle you have nothing to lose but a little time if you try to straighten the old axle once it is out of the tractor. It should not be hard to straighten it when it is out of the tractor. If it is, then go buy the new one.

 

[C4Ranch]

Taking the axles out of my old B7500 was easy.

Just a thought, but maybe it's just a bad bearing. Won't know till u get it apart. My B7500 bearing cage was broken no idea how that happened but it was well used when I bought it.

 

[nc redneck]

I would not try to repair axle in or out of tractor, very difficult to do correctly unless you have a machine shop. I have a BX2200 and mower deck should have spring loaded pins to pull for removal. If deck is welded and back axle is bent I think you may be correct and it fell off trailer at highway speeds.
If removing deck ( assuming it is welded ) is important to you I would probably resale tractor on craigslist.
Other option is just leave it as is and run it as long as you can, not sure how long bent axle seal and bearing will last. Depends on where it is bent. As long as it does not damage housing no loss.
Good Luck
Scott

 

[timebak]

ovrszd: After finding out that the housing was cast aluminum, I agree that trying to straighten the axle is a recipe for disaster. After studying various drawings in my shop manual, I've come to the conclusion that the axle really CAN be removed without pulling or tearing down the transaxle. Here are some supporting drawings:

First here is the axle assembly. The only items shown are the axle itself, the axle bearing, and an inside and an outside snap-ring:

This next drawing is a detail of the Differential Assembly with the axles installed. Note that there are NO snap-rings or anything else shown that would prevent the axles from being pulled out of the Differential Carrier assembly. Both snap-rings are shown on either side of the outer axle bearing, just behind the oil seal, thereby allowing pulling without transaxle disassembly:

The next supporting drawing is of the Differential Assembly teardown and re-assembly. Again, there are no snap-rings shown for the Differential assembly.:

So, I'm going to order the parts from Messick's and have at it when they come in. I'm also ordering the parts for the driveshaft refurb, including a next HST cooling fan. I'll post pics of the repair when I do it.

 

[buck boost]

Based on the above pictures, what holds the rear axle in? Just the external snap ring (outside circlip?)

 

[timebak]

Based on the above pictures, what holds the rear axle in? Just the external snap ring (outside circlip?)

Yep. That appears to be it. But there are a lot of cars that are the same way, and probably some trucks, too.

 

[buck boost]

I hear ya. I'm just surprised that C-clip is not on the inside of the differential. It could be a trick to install that oil seal with a fixed hub in the axle case.

That does not look like a big deal at all to change out an axle. I wonder if that ball bearing is pressed on the axle. I would think it should be. Otherwise there would be no way of keeping the inner race from spinning on the axle shaft.

 

[ovrszd]

It's pressed on. That's why a C-clip outside of the bearing can hold the axle in. You will see similar situations with rear axle shafts in 1/2 ton trucks.

You might try straightening the bent shaft after you get it out, before ordering a new one. But if it fails, then you are down longer waiting for them to get a shaft. I've just not had very good luck with doing that. And it'll take a very good press with the proper gear to hold the shaft while pushing on it without damaging the areas where bearings press on.

Take pics and give us a report when you do it.

 

[MessickFarmEqu]

I agree with replace it.A year or so ago I had to repair the dif lock on my B7800 and was pretty intimidated until I got into it.You will find that it is easier than you probably think and a whole lot cheaper than paying a dealer.We're really fortunate to have Messick"s for parts.

if you are ordering the parts for this, talk to Les in our service dept. We will talk you though doing the repair.