Clutch Spline Wear on B9200 HST

[Jugtown]

Wondering if anyone has seen this before and can give me some idea as to what would cause it.
I have a B9200 HST. Purchased used about 10 years ago. I'm at least the third owner. I don't really know how many hours on it since the meter has only three digits.
I split the tractor to replace drive shaft coupling and was really surprised at the wear on the clutch disks splines and shaft. The pilot bearing was completely gone.Photos attached. I would not expect that kind of wear on a HST.

A few years ago I put a new clutch in a sub compact tractor I have that has a gear trans. I've had that tractor since 1986 and used it to bush hog, loader work, some post hole digging, and snow plowing. The clutch disk was worn as was the release bearing as I expected with the type of use. But there was no wear on the disk splines.

 

[Lil Foot]

Haven't seen that on a tractor, but saw almost identical wear on a Jeep spline & clutch disc. Found out later that the disc that had previously been installed was the wrong one, and the splined hole was very oversize, and it quit working completely when the splines stripped out of the disc.
Is the shaft still available?
If not, a competent shop should be able to weld it up & recut the splines.
That is what we did on the Jeep.

 

[dfixit1]

Wondering if anyone has seen this before and can give me some idea as to what would cause it.
I have a B9200 HST. Purchased used about 10 years ago. I'm at least the third owner. I don't really know how many hours on it since the meter has only three digits.
I split the tractor to replace drive shaft coupling and was really surprised at the wear on the clutch disks splines and shaft. The pilot bearing was completely gone.Photos attached. I would not expect that kind of wear on a HST.

A few years ago I put a new clutch in a sub compact tractor I have that has a gear trans. I've had that tractor since 1986 and used it to bush hog, loader work, some post hole digging, and snow plowing. The clutch disk was worn as was the release bearing as I expected with the type of use. But there was no wear on the disk splines.

If the pilot bearing was completely gone, (I rechecked picture of shaft and you can tell bearing was there at one time).
That would explain the wear. If pilot bearing is an actual bearing make sure you use a good quality grease for lube. Look at specs of Mystic JT6 High Temp.
If bronze bushing, many are unaware you need to soak overnight in ATF.
With that much wobble I would also replace the bearing on the input shaft.
I also wonder if clutch disk was stuck to flywheel at some point?

edit: another thought or possibility is, maybe someone did an engine repair prior to your purchase and forgot to install the pilot bearing?

My clothes washer started making a noise during spin cycle. The tub replacement bearing is a bronze bushing. I lubed it instead of replacing. The washer never wrang out the clothes this well after lubing!

 

[SDT]

Wondering if anyone has seen this before and can give me some idea as to what would cause it.
I have a B9200 HST. Purchased used about 10 years ago. I'm at least the third owner. I don't really know how many hours on it since the meter has only three digits.
I split the tractor to replace drive shaft coupling and was really surprised at the wear on the clutch disks splines and shaft. The pilot bearing was completely gone.Photos attached. I would not expect that kind of wear on a HST.

A few years ago I put a new clutch in a sub compact tractor I have that has a gear trans. I've had that tractor since 1986 and used it to bush hog, loader work, some post hole digging, and snow plowing. The clutch disk was worn as was the release bearing as I expected with the type of use. But there was no wear on the disk splines.

Google fretting corrosion for everything you want to know.

Common on vintage Ford tractors with the Select-O-Speed transmission but I've not seen it on Kubota tractors.

SDT

 

[Pau7220]

a competent shop should be able to weld it up & recut the splines.

I've done that on an output shaft between a trans and transfer case. Work one spline at a time with the new disc. Hard wheels and cutoff wheels for shaping, flap wheel for finishing. Make sure the new disc slides freely without binding before moving on to the next spline.
A bad pilot would allow the disc to move out of center causing the fretting.

 

[Dave_eng]

Could you post a photo of the entire clutch disk.

I am interested in seeing the springs incorporated within the disk if there are any.

I posted this technical info earlier concerning clutch disk design and it may have relevance here particularly if someone replace the disk earlier with the wrong one.

Dave

 

[dfixit1]

Could you post a photo of the entire clutch disk.

I am interested in seeing the springs incorporated within the disk if there are any.

I posted this technical info earlier concerning clutch disk design and it may have relevance here particularly if someone replace the disk earlier with the wrong one.

View attachment 44981 View attachment 44982

Dave

Great article! Check with the Kubota dealer and see if there is a TSB for your tractor concerning the clutch. Also have them run a service inquiry to see if the clutch was repaired or replaced. Not for the purpose of placing blame but for diagnosing the cause of your clutch issue.

 

[Jugtown]

Thanks for all the replies.
Lil Foot: the shaft is still available, at $150, easier than trying to repair the old one.
Dave: attached pics of the disk. Thanks for the clutch article.

I did find some very small remnants of a pilot bearing.
There was no evidence that this tractor has ever been split for major work. The paint on the bell housing bolts and washers was still intact.

From all the comments I'm guessing the pilot bearing wore out and caused the disk to run off center.
I just thought it was odd that there was so much wear since you're not using the clutch that often on an HST tractor.

 

[Dave_eng]

Thanks for the photos.

To my surprise, the new disk on Messicks looks the same design with no springs.

Dave

 

[SDT]

Thanks for the photos.

To my surprise, the new disk on Messicks looks the same design with no springs.

Dave

Interesting, and bingo.

Fretting corrosion of the torque limiting (no release mechanism) clutch disc splines and, much more problematic, the transmission input shaft is a common problem of vintage Ford tractors equipped with the Select-O-Speed transmission (the world's first power shifting farm tractor transmission) built in the 50s and 60s. The torque limiting clutch used in such applications had no cushioning springs.

Similar Ford tractors equipped with gear drive transmissions using clutch discs fitted with cushioning springs have no such issues.

SDT