B2150 Shaft Coupler isn’t grabbing shaft

TNENGNR

New member

Equipment
B2150
Aug 8, 2025
3
0
1
Knoxville
I was concerned my clutch had failed but I removed the inspection cover and had a look at the shaft that connects the transmission to the HST. When I let off the clutch pedal this shaft spins but it cannot turn the HST shaft because the coupler is stripped out on it.

it looks like it could have gone back another 3/4 inch or so, so did it slip off somehow? Assuming I can’t save the splines on the HST shaft, is this something I can purchase and take apart the HST to replace or is it toast? How bad of an idea would it be just to weld the coupler to the shaft?

Does the case have to be split to get this coupler and intermediate shaft out or is is serviceable from the bottom?

The power steering and lift is working but the tractor won’t drive.
 

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Mountainman

Active member
Lifetime Member

Equipment
L2501, B7100, B2710 B21, B1750, B2400, B7200
Jul 10, 2022
443
180
43
Attalla Alabama
mossycreekoutdoors.com
You can tell in the picture the splines are stripped off. There also should be a roll pin pinning the coupler to the shaft. Its possible it has moved from where it should be but at this point i don't know that there would be enough good splines to move it back where it should be and be ok and/or if the splines on the coupler are stripped also. Unfortunately have to split the tractor to replace
 

TNENGNR

New member

Equipment
B2150
Aug 8, 2025
3
0
1
Knoxville
Thanks for the reply. I bounced around the internet trying to find where this has happened to others and it looks like it happens but it isn’t very common, lucky me.

Another gentleman used the spring pin holes to insert a grade 8 bolt and he said they kept snapping almost immediately, so that’s not even a temporary repair. There is a rubber oil seal an inch away from where I would be welding so that’s out.

Best I can tell the shaft is heat treated solid steel but the coupler is just cast, so it’s soft. I guess they did this so the coupler would fail before whatever caused it to fail also ruined the HST.

At any rate it looks like to repair it properly I’m taking the whole thing apart as you said. I found a YouTube video of a clutch replacement and I’m hoping that will get me most of the way there. Sounds like a good project for the Fall when it cools off!
 

Mountainman

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Lifetime Member

Equipment
L2501, B7100, B2710 B21, B1750, B2400, B7200
Jul 10, 2022
443
180
43
Attalla Alabama
mossycreekoutdoors.com
The shaft is hardened and the coupler is softer so typically the coupler fails but i have seen several that also stripped the shaft splines. I think the main problem is its not greasable and i can't remember what its called but that red stuff that builds up between the splines weakens the splines. But to this day kubota still hasn't made those couplers greasable at least on the smaller tractors. And still designing it to have to split the tractor to repair. If you split at the clutch housing youll still have to remove the tunnel to get the hst out so you could just split it there.
 

Oleracer

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Equipment
B2150 Kubota LA 350 750 Woods S250 Bobcat 300x deere
Jul 18, 2024
243
280
63
CT
Is the coupler still available… have bad feeling i broke it on this bad snow storm. 250 hour b2150hst. Noise let clutch out no drive. Fun i guess.
 

North Idaho Wolfman

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L3450DT-GST, Woods FEL, B7100 HSD, FEL, 60" SB, 743 Bobcat with V2203, and more
Jun 9, 2013
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Sandpoint, ID
Is the coupler still available… have bad feeling i broke it on this bad snow storm. 250 hour b2150hst. Noise let clutch out no drive. Fun i guess.
Yes they are available
 
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