L4400 cracked rear hubs

[CptTrog]

Folks, sorry if this is a duplicate question, but the forum search engine is simply not helping me find any info. I know it's been addressed somewhere here.
Kabota L4400 rear hubs are spiderwebbing at the lugs. (Cheap steel or bad design?? Or maybe it's me.) I've purchased new hubs to replace the old ones. Here's my question:
Should I try to reinforce the new hubs somehow prior to installation? I'm using a backhoe attachment A LOT in very rocky terrain here in Virginia. Also operating on some pretty hairy grades when mowing or box blading. Also have all four tires filled with antifreeze.
I've considered having a local welding shop cut and drill two rings for me from 1/4 steel and weld them to the outter surface of the new hubs.

Any feedback? Thanks!

 

[srs]

Cpt. any chance you could post a couple of photos?

 

[azbinder]

Are you talking about the center of the wheel itself or the hub that is part of the axle?

 

[Chilly807]

Are you talking about the center of the wheel itself or the hub that is part of the axle?

That's the question I had too..

Sean

 

[art]

The end of the axle shafts are cast iron and you need to pull the axles to replace so I'd say this is a wheel problem.. You could possibly buy new rims that have a reinforcement ring built into it. By Kubota books rear ballast with a backhoe? I don't normally recommend filled front tires at all. For what it sounds like you are doing you might want to look at the L-45.

 

[CptTrog]

At some time in the past, I had photos of the problem. Can't seem to locate them now. The specific issue is the cracks that are appearing in the wheel's center disk, in the metal surrounding the holes for the lug studs. Some have become bad enough that I simply will not operate the tractor before I have them replaced. (I don't trust the metal quality enough to repair them.) I've purchased new wheel disks and am looking to reinforce them prior to installation.
As far as the filled tires, this was recommended and done by the dealer based on the terrain and their suggestion that it would greatly lower the center of gravity for the tractor. I am having second thoughts due to the stresses this may be placing upon the wheels.

 

[KYDan]

How old are the original wheels and were the tires filled with calcium chord?

 

[Grandad4]

First, welcome to TBN. Good people here and a lot of knowledge.

I've been following Kubota on TBN since about 2002 and if this was mentioned before I missed it. I'll admit that's not saying a lot :laughing:, but if there were a general quality problem, you'd have to think it would have appeared more often in these forums. So I would have to respectfully offer that there might be something in the daily operation of your L4400 that is putting extreme side or flex loading to those hubs. The most obvious is keeping the wheel lugs tight. That's been mentioned recently, and really demands regular maintenance. Going from there, your description provides three clues:

I'm using a backhoe attachment A LOT in very rocky terrain here in Virginia.
Also operating on some pretty hairy grades when mowing or box blading.
Also have all four tires filled with antifreeze.

Just my opinion, but #2 and #3 are probably unlikely to be the problem. Unless you're racing the thing over a rock course, I can't see how you'd drive it so rough you'd crack the wheel without killing yourself or breaking something else first. But there's a lot you can do with a backhoe that will put extreme loads on the rear wheel hubs. For example, if you dig with the boom off to one side and don't have the rear stabilizers carrying the weight of the tractor, guess where all the loading will go... right to those wheel hubs that are failing on your tractor. So that statement about using the backhoe a lot in rocky terrain gets me thinking that has something to do with your problem.

 

[art]

Do you have the wheels moved way out to help with the hills?

 

[azbinder]

Do you have R1 Ag tires with 2 piece rim and disc (disc bolts to axle flange and then the disc bolts to the rim) or R4 industrial tires with one peice rims? Also, the wheel flange is part of the axle and is NOT replacable.