Kubota B3030 HSTC

[taterpicker]

Plowing snow today noticed a clunking noise. forward or reverse. 4 wheel drive only. all three transmission ranges. sounds like a cog missing off a large gear. 10 years old, 500 hours. light use. proper maintenance. no incidents that would have caused damage to drive line.

 

[TripleS]

Sounds like either a front axel universal joint or front drive shaft universal joint

 

[whitetiger]

Sounds like either a front axel universal joint or front drive shaft universal joint

The B series does not have a universal joint in either place.

 

[ptsg]

Sounds like it stripped one of the splined couplers between the transmission and the front axle. Are you on 4WD a lot? Specially on hard surfaces?

Had that happening to me on a B7000. That one used u-joints instead of a straight coupler but it's the same principle.

 

[rScotty]

Sounds like it stripped one of the splined couplers between the transmission and the front axle. Are you on 4WD a lot? Specially on hard surfaces?


View attachment 846594

Had that happening to me on a B7000. That one used u-joints instead of a straight coupler but it's the same principle.

Several here on TPN refer to Kubota's splined FWD coupler as being a part that is designed to wear out so that it protects the rest of the front drive components.... I've no idea if it was designed for that, but apparently that is what it does.

The symptoms match, easy & inexpensive to replace. Look there first. You will have to undo the drive shaft cover. Most of the covers telescope.
rScotty

 

[Paystar]

Several here on TPN refer to Kubota's splined FWD coupler as being a part that is designed to wear out so that it protects the rest of the front drive components.... I've no idea if it was designed for that, but apparently that is what it does.

The symptoms match, easy & inexpensive to replace. Look there first. You will have to undo the drive shaft cover. Most of the covers telescope.
rScotty

I don't know if they are "designed" to wear out, but I had an old Case backhoe that used one of those to drive the hydraulic pump off the front of the engine and I remember changing them every couple years.

Or maybe you mean they are designed to wear before the splines on the shafts do.

 

[rScotty]

I was thinking the same thing. A part like that coupling is going to move and wear, so it would make sense to make it of a material that would wear faster than the splines on the shafts.

So it makes sense that anyone who designed that type of coupling would tend to specify materials to make the coupling wear faster. Maybe not as a truly sacrificial part, but as a side benefit.

Another thought was that if the splines and coupling were intended to wear at the same rate, there would be some way to lube it and keep it lubed.

rScotty

 

[taterpicker]

I doubt it would be a spline problem as both front wheels work as designed. Only hear the clunking noise at about every half rotation of the front wheels

 

[Paystar]

I doubt it would be a spline problem as both front wheels work as designed. Only hear the clunking noise at about every half rotation of the front wheels

Bad bearing? Any seals sweating yet?

 

[rswyan]

I doubt it would be a spline problem as both front wheels work as designed. Only hear the clunking noise at about every half rotation of the front wheels

B2910 here, believe the drivelines are substantially similar.

Blew the rearmost u-joint on the drive line going to the front axle @ around 2400 -2500 hours while dropping it into 4WD pushing the loader into a manure pile.

Managed to destroy the yoke halves as well.

Kubota calls for splitting the tractor to replace it. It can be done without doing that, but it’s a bear.

The driveline is contained in a tunnel that connects the front (bell housing, engine) of the tractor to the rear (hydro, transmission)

Front axle has to be dropped to remove the driveline and a hole (2” ?) has to be punched in that tunnel that connects the front of the tractor to the rear - so the yoke can be (roll) unpinned from and then pinned to the output shaft on the transmission. Can’t get to it otherwise.

Think there’s a write up on here somewhere of a guy that did it, could have been on another site though. Didn’t have much in the way of pics IIRC.

See if you can isolate where the noise is coming from.

If it is that u-joint, let me know and I’ll post some pics of what I did.

Most critical thing to know is where to punch the hole in the tunnel with the hole saw - so you don’t end up cutting the hydraulic hard lines that run through the tunnel.

Good luck.