I am a licensed A&P mechanic, so get ready for an earfull. My B2710 has 800 hours on it and has always been operated with manufacturer's suggested limits. The rear R4 tires are filled with beat juice and alot of the tractors use has been devoted to hauling loads with the FEL downhill. The heavier loads were transported down hill backwards (700-800 pound range) while the lighter loads (400-500 pounds) were transported downhill in the forward direction, both on Low -4WD. The slope of the concrete driveway is a 15 degree incline and about 200 yards in length. There was a klunking noise coming from the front axle bevel gear assemblies which was synchronous with the front wheel's rotation and at time slippage was heard and felt as the tractor went down the driveway even without a load. I removed the front tires and pulled each bevel gear housing on the front axle assembly. I then proceeded to disassemble each bevel gear housing and inspected the gears and bearings.
The wheel ring gears were severely worn to the extent where 7-9 teeth had broken off and the shaft gears were severely worn. The ring gears were taken to the metallurgy lab and X-RAYED. Unacceptable fissures were found in the ring gears eminating from the casting process at the time the gears were manufactured. Both ring gears and shaft gears were replaced along with the bearings, shims, O-rings and seals. The total repair time was about 2 hours.
The parts cost was close to 2000 dollars. The ring and shaft gears have to be purchased as a machined set.
My advice is that when you buy a Kubota tractor, you spend a few hours and disassemble the front wheel bevel gear housing and have the ring gears inspected for casting fissures and cracks, either by X-RAY, ultrasonic or eddy current testing. If any fissures are detected, document your findings and return the tractor.
It is only a few hours of work with a good set of snap ring pliers. Metallurgy cost and analysis is about 250-500 dollars and well worth it. It can save your life. I was very close to a downhill run-a-way tractor with a load in the front end loader using 4WD.
The wheel ring gears were severely worn to the extent where 7-9 teeth had broken off and the shaft gears were severely worn. The ring gears were taken to the metallurgy lab and X-RAYED. Unacceptable fissures were found in the ring gears eminating from the casting process at the time the gears were manufactured. Both ring gears and shaft gears were replaced along with the bearings, shims, O-rings and seals. The total repair time was about 2 hours.
The parts cost was close to 2000 dollars. The ring and shaft gears have to be purchased as a machined set.
My advice is that when you buy a Kubota tractor, you spend a few hours and disassemble the front wheel bevel gear housing and have the ring gears inspected for casting fissures and cracks, either by X-RAY, ultrasonic or eddy current testing. If any fissures are detected, document your findings and return the tractor.
It is only a few hours of work with a good set of snap ring pliers. Metallurgy cost and analysis is about 250-500 dollars and well worth it. It can save your life. I was very close to a downhill run-a-way tractor with a load in the front end loader using 4WD.
