Broken bolt

[JRobyn]

Almost looks like a situation where the two mating parts of the axle hub were held together by just an upper and a lower bolt and the lower bolt was missing. Such that the weight of the tractor put huge leverage on the bolt in question to both bend and tension it as the mating parts started to come apart. Obviously, if this was the case and other bolts were missing, the hub wold have completely fallen apart when this bolt broke. Maybe an error like this occurred during assembly and the worker just "hid" it? Puzzling!

If I were in OPs shoes, not only would the dealer be TOTALLY fixing this, but also thoroughly inspecting (and torque checking) a LOT of other fasteners, and I'd be asking for additional extended warranty at no cost.

 

[dragoneggs]

If I were in OPs shoes, not only would the dealer be TOTALLY fixing this, but also thoroughly inspecting (and torque checking) a LOT of other fasteners, and I'd be asking for additional extended warranty at no cost.

Especially anything to do with the front axle.

 

[dougtrr2]

With all the millions of bolts that are made there is a chance that this was just a freak manufacturing defect.

Doug in SW IA

 

[GMIslander]

With all the millions of bolts that are made there is a chance that this was just a freak manufacturing defect.

Doug in SW IA

I kind of like this idea. I wouldn't read to much into this. Get it changed on warranty and move on.

 

[Shaneard]

I kind of like this idea. I wouldn't read to much into this. Get it changed and move on.

I actually started typing that yesterday and stopped. You can over analyze things as far as you want to take it. The bottom line is a bolt broke, replace it and move on. If it breaks again start trying to figure it out if it isn't obvious.

 

[ovrszd]

I'll stick with my initial thoughts that a Kubota certified mechanic needs to be involved, under warranty. Then if it's a simple bolt failure, cool. If it's something more dramatic and further work needs done, cool.

 

[Spud68]

Just wanted to give an update. Dealer extracted the broken bolt, inspected and replaced both bolts on that side. they are saying probably just a bad bolt. they will investigate further if more problems occur. But the problem is documented. Tractor is back in service and seems to be working fine.

Thanks to all who offered advice and assistance. it is much appreciated!

Teddy

 

[ovrszd]

Thanks for the update. Hope that's the end of that problem!!!

 

[Shaneard]

Thanks for the update. Hope that's the end of that problem!!!

I'll second that!

 

[PILOON]

I'll also add a thanks as so many post problems and never do a follow up.
We all appreciate them.

 

[LSU L4330]

I know this is an old thread but I was researching this exact issue and this is the only info I have found on this so far. I just had the exact, to a T, same issue happen to my L4330. I've had this tractor for a long time and never had any issues so it's not a new over torqued bolt. I was just doing routine greasing of the fittings around the tractor and when I went to this exact left front side top zerk and started pumping grease into it I heard a LOUD bang and then looked down and noticed the bolt mating surface location was higher and no bolt head was there anymore. Found the exact same looking sheared off bolt head as shown earlier in this thread laying under the tractor. Not sure exactly what I'm getting into tearing this apart to drive the rest of the bolt out and put a new one in but I'm fixing to find out. I was waiting to see a little grease coming out from under that upper knuckle cover when the bang went off. Never saw any grease coming through. I thought I vaguely saw reference when researching this that there may be a bleed bolt that needs to be removed when greasing this location. Not sure where that is and never noticed it but I could be wrong on that. Only thing that has remotely explained a possible cause. Any others had this same issue at this location and how are y'all greasing this zerk?

 

[SDT]

You guys are AWSOME! I wouldn't have thought it was possible either???? I'll try to attach the pic here.

1. the white circle is the horizontal bolt that sheared off. the arrow points to the zirk used to grease the knuckle.

I dont have a problem extracting the bolt and replacing. are there any tricks/tips in the procedure? It looks straight forward only 2 bolts.

Thanks again!
TeddyView attachment 497646

Either defective bolt or over-torqued at some point.

I would have the dealer repair under warranty.