Case 85c Cracked Wheel Hubs

[LeglaNonto]

Friend of mine picked up a 2009 Case 85c at an auction, only 90hrs on it. It came with turf tires. Upgraded to Ag tires; after install, dealer recommended light use for a couple days then a re-torque.

Re-torqued yesterday with a calibrated Snap-On torque wrench to manufacturer spec (180 lb-ft I think). Didn't require much force; they were by no means loose and had not been over tightened.

He heard something fall on the ground, figured it was just dirt. Continued. Heard something fall on the other side. Investigated. Two of the points where the lug attaches to the hub had broken off completely. One on each side. A couple other points were splitting and spiderwebbing. That sinking feeling creeps in.

All the splits were new, there was no rust like there would have been if it was a pre-existing break. Have a look at the pics. The ones that had broken off completely are being held on with a longer lug, washer and nut.

I haven't seen anything like this. The few posts I've found with an issue like this have been from overloading or loose rims on rough terrain. The tractor only has maybe a 100hrs and has had a very gentle life so far. The dealer said they haven't seen this before and they use these rims all the time. In their experience if you over tighten a lug you'll strip it before you break the hub. Of course its a 2009 and outside of warranty and replacing the hubs means disassembling the planetary gears in the front end.

Thoughts?

 

[LarJea]

The only way I could see that happening is if the mating surface of the wheel was not concentric with the hub.

 

[jimmysisson]

Whatever the cause it stinks. Is there a Service Bulletin from Case on this? Case should want to know the cause and help you with the effect. Grrr
Jim

 

[sd455dan]

Some of the pictures make it look as if the holes in the wheel are actually pulling the studs at an angle- almost as if the bolt hole diameter of the 6 holes in the wheel is different than the 6 studs diameter on the hub??

 

[LeglaNonto]

I'm sure he'll be digging into it today. The dealer took a pretty close look regarding mating surface, alignment, etc. and just scratched his head. Haven't heard of any service bulletins from Case. I'll post if I hear anything.

 

[Baby Grand]

Well, shoot! That's got to be about the most disappointing upgrade I've ever seen
I'd want to check some new stock hub & bolt threads with a go/no-go gage.
Looks like the tread fit is too tight, creating a bursting stress on the hub flange.
Incomplete threads in the hub could create this problem.
Maybe the tap wasn't run deep enough into the cast part, resulting in an undersized thread at the very end of the hole, where the shank of the bolt sticks out?
-Jim

 

[Mysfyt]

Some of the pictures make it look as if the holes in the wheel are actually pulling the studs at an angle- almost as if the bolt hole diameter of the 6 holes in the wheel is different than the 6 studs diameter on the hub??

I'll add a second vote for this. Check the bolt circle diameter of the wheel compared to the hub.

 

[LeglaNonto]

A tech from Unverferth (the rim manufacturer) is suppose to come out and take a look at the rims; they are the only thing that has changed. There was never a problem with the rims on the turf tires.

It looks like the hub is not a perfectly flat surface to mate to. The tip of the furthest point of the hub is about 30 thou out of flat to the lug holes. There is really no flex to cast steel, so if there is stress on the tips of the hub I could see it splitting. Not sure who is out of spec though, Case or Unverferth... Or if its something else entirely.

Machining on bolt diameter looks good.

 

[boggen]

most rims for tractors are universal. swap them left to right side. and turn them around etc.. to gain shorter or wider stance of tractor tires. so to have a non flat surface *scratches head*

kinda wondering if someone got the wheel down into an ugly rot with trees / rocks or like on both sides. and just bent something to point of cracking?

i could also see a "newbie" or perhaps honest mistake at some manufacture plant. and something happening perhaps some sensor went down and read things wrong during manufacturing?

 

[sd455dan]

Any Updates?- this is an interesting thread