B3030 Front End Locking Up (Video)

[Chaldaean]

The front end started locking up this afternoon and intermittently comes to a halt.

Here is a video to show behavior (tractor is in 2 wheel drive):Kubota B3 Front End Locking Up - YouTube

It wanted to limp it back to the garage, but couldn't only manage to get it moved a few feet.

I was home during lunch break to pickup some leaves and had to get back to work, so I couldn't spend time troubleshooting (lifted the front end, spinning by hand etc.). I hope to do that tonight.

Does anyone have insight regarding troubleshooting, potential causes and solutions? I'm handy and would like to fix it myself to save money, but will take it to the dealer if the group thinks this will be a can of worms.

Thanks for the support!

 

[bg71361]

Check your link, didn’t work for me

 

[Chaldaean]

Thanks; link is fixed

 

[moship]

Is only the passenger side locking up?

It's fairly easy to remove the wheel hub assembly. An o-ring is used to seal and can be reused if not damaged. So there are no parts that need to be procured to remove and replace for inspection.

I wouldn't hesitate to disassemble as it requires minimal work and you'll be able to see first hand if a ball bearing or gear is failing. My guess is a bearing is coming apart and jamming in the gear.

Keep us posted on what you find and good luck!

 

[KennyV]

Is only the passenger side locking up?

I think this is on a B3030, tractor,... it has No passenger accommodations, however there are much larger AG tractors that do have passenger seats, generally on cab models, on the Left side of the operator station. KennyV

 

[moship]

Curious what the OP found wrong. Care to report?

 

[Chaldaean]

Curious what the OP found wrong. Care to report?

moship, I'm still in the middle of the repair, but the quick news is that the teeth on the pinion and ring gears are damaged. The debris migrated into both (left/right sides) bevel gears and there is some collateral damage in those bearings (retainers damaged etc.). I have the whole front axle off of the tractor and pulled apart every component. I'm waiting on receipt of gears, bearings, backlash spacers, seals, etc to complete the repair. So far, I'm at $500+ in parts. Here's a shot of the ring/pinion set....

 

[Michford]

moship, I'm still in the middle of the repair, but the quick news is that the teeth on the pinion and ring gears are damaged. The debris migrated into both (left/right sides) bevel gears and there is some collateral damage in those bearings (retainers damaged etc.). I have the whole front axle off of the tractor and pulled apart every component. I'm waiting on receipt of gears, bearings, backlash spacers, seals, etc to complete the repair. So far, I'm at $500+ in parts. Here's a shot of the ring/pinion set....

View attachment 580890

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

 

[moship]

Thanks for sharing ,but I’m sorry for the extent of damage you’ve found.

It’s hard to imagin the circumstances that initiated the initial failure before it snowballed into what you have now.

Good luck with the repairs.

 

[diesel85]

Looks like defective castings/materials.

 

[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.

View attachment DSC_9809.JPG

 

[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).

View attachment 582576

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.