B3030 Front End Locking Up (Video)

[MHarryE]

Have you shown this to the dealer? Appears the gears may not be meshing properly overloading the inner tips but is hard to see the normal wear pattern. Brother in laws L3000 which I believe is the older version of your series had no grease zerks on the axle trunions. He did a lot of loader work in 4wd and wore the trunions so bad the axle flopped back and forth with each directional change and messed up many drive components. Hopefully Kubota has taken care of that defect.

 

[Chaldaean]

...Any idea what caused the damage to the teeth on the ring and pinion?

No idea. i got the tractor used with 800 hours from a farm in Kentucky (purchased through Barlow Farm Equipment), so I don't have complete history.

Have you shown this to the dealer?

I have not, but Kubota did redesign something. When ordering parts online, I have a choice between two designs based on tractor serial number. My tractor is the first iteration.

Some quick notes:

- Overall, it is a job that can be done in a home garage. The most uncommon tool is an inch-oz range torque wrench to measure the 0.59-0.73 lbf-ft turning torque on the spiral bevel pinion shaft.
- The most difficult part was ensuring proper gear backlash. This requires the purchase of multiple thickness collars/spacers and, in my case, multiple attempts of assembly/disassembly to get it right. I tried to use a dial indicator with an extension probe mounted to a magnetic holder, but couldn't get a repeatable reading. I used the procedure Kubota recommends in the manual, which is to employ a "fuse" (I just used lead electrical solder), which smooshes between the gears as they are manually turned. The thickness of the deformed fuse correlates to the backlash. I found it useful to hold/fixture the axle tube vertically to make it easier to lay the solder on the ring gear; otherwise, it was hard to keep the solder in the right place.

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[Langanobob]

Good job you are doing. You are fortunate to have the skills to to do your own work, would have cost a lot more if you had to pay the dealer. Puzzling about the cause, maybe a bearing failed and pieces got between the gears?

 

[Michford]

Thank you for the great pictures and explanation of what is involved in the repair.

 

[repete]

My bevel gear housing uses an O ring to seal. Yours looks to have had some sealing material like silicone used but I cannot tell 100% by the first picture. I will bet if you pull off the bevel gear housings you will find problems as well.

 

[Chaldaean]

...maybe a bearing failed and pieces got between the gears?

The bearings in the main axle tube looked okay. I could have re-used them, but replaced them since I don't plan to be in there again.

My bevel gear housing uses an O ring to seal. Yours looks to have had some sealing material like silicone used but I cannot tell 100% by the first picture. I will bet if you pull off the bevel gear housings you will find problems as well.

Yeah, you are correct, the bevel gear housing is sealed with silicone and I did find problems. I tore into both sides and found debris and a bearing with a busted retainer so I replaced all the bearings (which were surprisingly affordable from the dealer at around $5 each; Japanese made).

 

[repete]

The bearings in the main axle tube looked okay. I could have re-used them, but replaced them since I don't plan to be in there again.



Yeah, you are correct, the bevel gear housing is sealed with silicone and I did find problems. I tore into both sides and found debris and a bearing with a busted retainer so I replaced all the bearings (which were surprisingly affordable from the dealer at around $5 each; Japanese made).

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View attachment 582577

I know these bearings well. I used to trash the outer bearings all the time until I turned my wheels to a narrow position and then the center of the wheel was aligned with the center point of the two bearings. I assumed that was the way the designers planned as opposed to the outer bearing handling the majority of the weight. My extra bearings and seals are gathering dust now.