Kubota B3030 72" mid-mount mower

[Ovo Pearson]

Cutting grass the other day with Kubota B3030 72" mid-mount mower. While cutting, the tractor died. Turned mower lever off, restarted tractor. Engaged mower, tractor died. Disconnected drive shaft to mower deck and turned blades by hand. Attempted to turn drive shaft by hand, cannot turn it. Checked deck for any debris, nothing interfering with the belt externally.

Any suggestions on troubleshooting? I'm thinking it may be the gearbox, but seems odd that it suddenly seized while operating.

 

[seville009]

It’s been awhile, but on my Ferris ZTR, the mower engagement switch went bad and I had to replace it. It’s been to long to recall what exactly occurred when it happened, but that may be something to look at.

 

[JWR]

Please clarify WHICH driveshaft you could not turn by hand -- the one feeding the gearbox on top of the mower deck? Was it loose from the mid PTO when you tried ?

 

[Ovo Pearson]

Please clarify WHICH driveshaft you could not turn by hand -- the one feeding the gearbox on top of the mower deck? Was it loose from the mid PTO when you tried ?

Disconnected drive shaft to mower deck and turned blades by hand. Attempted to turn drive shaft by hand, cannot turn it.

There's only one drive shaft for the mower deck.

 

[LittleBill21]

and you checked the oil level of the gear box right?

 

[JWR]

Disconnected drive shaft to mower deck and turned blades by hand. Attempted to turn drive shaft by hand, cannot turn it.

There's only one drive shaft for the mower deck.

True but that one drive shaft can be disconnected at either end. I was just trying to be sure what you were saying.

So back to the issue: If you can turn the blades by hand but cannot turn the input shaft to the gearbox there are not many possible culprits. Is the belt moving when the blades move? I assume so ...and that means the drive pulley on the output shaft of the gearbox is turning. Therefore, Apparent broken gearbox as you figured to begin with. In other words, if the output shaft of the gearbox rotates freely and the input shaft is frozen solid you definitely have a bad gearbox.

May or may not be repairable depending on what broke and how much internal damage there is. Most shops are going to say replace the gearbox. Depending on where you are and what good experienced machine shops you have around it may be repairable. Used gearboxes will be VERY hard to find, even more so because the 72" decks are less common than 60 inch. I doubt the gearboxes are interchangeable but someone knows. Ask Messicks parts dept. Internal gearbox issues could be many things -- say a whole tooth broken off and lodged between others locking a shaft from turning, who knows.

 

[Ovo Pearson]

Thanks. Going to be taking it apart. No shops within an hour of me, so I'm it's all diy. Didn't want to take the gearbox apart if I didn't need to, but it doesn't seem like anything else.