B7100 seized.

[SidecarFlip]

I never want to do that procedure, not that I could because of the sheer size of mine. An overhead hoist would be in order and a lot of grunting, shoving and cussing too.

Just hope my damper plate outlasts me....lol

 

[torch]

I never want to do that procedure, not that I could because of the sheer size of mine.

I guess that's the other side of the "buy the biggest tractor you can afford" philosophy. I can "afford" to fix mine myself .

 

[SidecarFlip]

I guess that's the other side of the "buy the biggest tractor you can afford" philosophy. I can "afford" to fix mine myself .

Not really. You size tractor is incapable of doing what mine does and in reality, mine are mid sized utility units compared to many.

It's all about the intended end use. In my case, mine farm. yours may farm in a limited sense but certainly not at the degree mine do.

I find in some cases that having around 100 pto horsepower is marginal at best. I'd like to have 150 or 200 at times.

 

[torch]

Not really. You size tractor is incapable of doing what mine does

No argument there. If you need a bigger tractor then you need a bigger tractor. I was just observing that the decision has long lived repercussions, and the price of larger tractor ownership is not limited to the sticker price on the windshield.

Assuming it is not an open-station model, of course!

 

[North Idaho Wolfman]

Excellent to hear you got it all back together!

 

[torch]

I'm dragging up this old thread because, well, it's less than 2 years old AND IT HAPPENED AGAIN!

The other day I fired up the tractor to take care of the snow. The clutch wouldn't release when I stepped on it to engage the PTO. We'd had a day of rain before temperatures plummeted so I thought maybe the friction disk was frozen to the flywheel or something. I shut the tractor off, engaged the PTO, restarted and blew out the driveway without issue.

Same deal yesterday -- clutch didn't seem to fully disengage when shifting in the PTO. But this time, when I was about 3/4 done, it started to make loud rattling sounds. The noise disappeared when I reduced RPM, so I drove it straight to the garage and shut it down.

I split it today, and this is what I found:

The clutch was all new Kubota brand parts, from a reputable Kubota dealer. Shaft is straight, pilot bushing unworn. What the Aitch-Eee-double-hockey-sticks would cause it to tear itself apart like that???

 

[PoTreeBoy]

I'm dragging up this old thread because, well, it's less than 2 years old AND IT HAPPENED AGAIN!

The other day I fired up the tractor to take care of the snow. The clutch wouldn't release when I stepped on it to engage the PTO. We'd had a day of rain before temperatures plummeted so I thought maybe the friction disk was frozen to the flywheel or something. I shut the tractor off, engaged the PTO, restarted and blew out the driveway without issue.

Same deal yesterday -- clutch didn't seem to fully disengage when shifting in the PTO. But this time, when I was about 3/4 done, it started to make loud rattling sounds. The noise disappeared when I reduced RPM, so I drove it straight to the garage and shut it down.

I split it today, and this is what I found:

The clutch was all new Kubota brand parts, from a reputable Kubota dealer. Shaft is straight, pilot bushing unworn. What the Aitch-Eee-double-hockey-sticks would cause it to tear itself apart like that???

Looks like one of the release fingers broke? Did you replace the pressure plate last time? I ask because on the old pictures it looks like the end of one of the fingers has ground down against something, maybe the throw out bearing. Maybe some kind of problem in the release bearing area? In any case, I think I'd try aftermarket parts this time. Maybe the harmonics are enough different to prevent a recurrence if that's the cause. (And PoTreeBoy likes to save a buck, especially when OEM has failed.)

 

[North Idaho Wolfman]

I'd like to see the flywheel.
I've seen them do things like this with a bad flywheel.

 

[North Idaho Wolfman]

Looks like one of the release fingers broke? Did you replace the pressure plate last time? I ask because on the old pictures it looks like the end of one of the fingers has ground down against something, maybe the throw out bearing. Maybe some kind of problem in the release bearing area? In any case, I think I'd try aftermarket parts this time. Maybe the harmonics are enough different to prevent a recurrence if that's the cause. (And PoTreeBoy likes to save a buck, especially when OEM has failed.)

The fingers look fine to me???

 

[torch]

Release fingers are fine, throwout bearing is fine. Everything was replaced 2 years ago: pressure plate assembly, friction plate, pilot bearing, pilot bearing oil seal, throwout bearing.

Flywheel was checked in situ and on a surface plate last time. Less than 1 thou TIR. No signs of burnishing or high spots. On my way out the door right now, I'll try to figure out how to post a picture of it from work later today.

 

[torch]

The flywheel:

 

[Lil Foot]

I have seen that kind of damage twice.

One was on an old ford truck, clutch changed out by an inexperienced high school kid.
He missed the severely bent input shaft, bad front bearing, & no pilot bushing. It self destructed in days.
But you checked all that, so no joy there.

The second was on a jeep, experienced mechanic changed out the clutch, and it blew apart (quite noisily)
on the test drive. He said it sounded like a dryer full of old car parts. Forensic examination revealed that the new rivets that held the splined hub to the disc had been pressed in, but not peened over, when they fell out under load, it trashed itself. It was a rebuilt unit, and the supplier made good on a new clutch, and even refunded his money for his troubles.

That is all I've got. That is a head scratcher, keep us informed.

 

[torch]

Forensic examination revealed that the new rivets that held the splined hub to the disc had been pressed in, but not peened over, when they fell out under load, it trashed itself.

Hmmm. The two riveted halves have definitely separated. I'll have to have a real close look at the rivets when I get home again.

 

[torch]

3 of the 4 rivets pulled out of the holes in one plate, however I can't tell if they caused the failure or resulted from it.

I installed the new friction plate today and am back in the snowblowing business. Clutch operates nice and smooth when holding the HST pedal down and just using the clutch pedal. Fully engages, fully disengages. No unusual noise or vibration.

We'll see how long it lasts. Hopefully more than 2 years this time.

 

[Lil Foot]

Sounds good, hope you solved the problem.

 

[JohnDB]

Besides the obviously missing piece and missing spring, there's another crack beside another cushion spring that doesn't really show up in the photos.

Glad to hear that it wasn't worse.
Can you tell if the clutch disc is genuine Kubota?

 

[torch]

Can you tell if the clutch disc is genuine Kubota?

Good question. In both cases, the parts were ordered from a reputable Kubota dealer. They arrived at the dealer promptly -- I ordered this one Tuesday afternoon at 4:25 pm, they had it in by Thursday morning at 8:20 am. The box has a Kubota label on it and the price was the same as Kubota's website.

So I think it's real, but anything can be forged. In one of the most infamous cases of counterfeit parts in a supply chain, Air Force One was found to have understrength bogus bolts installed.

Hopefully there's not enough money in ersatz B7100 friction plates to make faking them worthwhile.

 

[cmorningstar01]

Have you checked the transmission input shaft bearing?
The pilot bearing stabilizes one end but the transmission input shaft bearing could be worn.

 

[200mph]

Perhaps your tractor is experiencing more harmonics than others. Maybe there is a small issue with compression imbalance between cylinders, slight injector issue or other that might be creating a slightly different harmonic that is more damaging. Personally think this is low on the possibilities, but also not aware of the mechanical condition of the engine.

 

[torch]

Interesting point. I did not check that specifically, and I'm not sure how much effect it could have. The transmission input shaft is connected to the clutch via a "propeller shaft" -- basically the splined shaft that engages the friction disk is a short driveshaft that is in turn connected to the transmission input shaft by a CV type joint.

It appears from the diagrams that the transmission input shaft (which also serves as the output shaft driving the PTO gearbox runs through two sets of ball bearings and a set of needle bearings in an oil bath. It directly drives the HST charge pump swash plate. There is an oil seal at either end. I think if there was a bearing problem inside the HST transmission, it would manifest itself in other ways.

However, I will have to check that CV joint. It is possible that it is worn out. I should be able to check for play from underneath, where the clutch release shaft grease zerk is accessed.