Kubota B7200D Bad Clutch- Need advise on Changing it out.

[TheOldHokie]

So what you are saying is that these machine shops are like the soup Nazi on Seinfeld.

I would say worse than The Soup Nazi. And for good reason - a "real" machinist has much more experience and greater engineering knowledge than all but a handful of customers. I am NOT a machinist but I have known and worked with some very good ones. You won't find people like that at most automotive machine shops.

Dan

 

[North Idaho Wolfman]

If you have a boring bar why use the engine as the drive?

Dan

Think of it as the engine is now the drive of the lathe.

 

[North Idaho Wolfman]

One thing I would like to point out, the pilot bushing does very little work in this scenario.

JB weld or anything similar would be under very little stress.

Over complicating it by putting a bearing in it, where it's not supposed to go, can cause you some serious issues down the line.

A bearing is not able to take shock loads, where a bushing can, there is a reason they used a bushings on these engines.

 

[TheOldHokie]

Think of it as the engine is now the drive of the lathe.

I think we are talking about two different "boring bars". Here is the boring bar I thought you meant. Its not a lathe but it is portable and does spin a boring tool holder. Sort of a mag drill on steroids.

Dan

 

[kubotafreak]

I was looking closer at that input shaft assembly. It is a lobro style joint. I can absolutly see now how if it locked up would force side loads like it did. Lobros are cool, but when they lock they don’t move. Generaly you see these in drivetrain multi piece driveshafts.
That input assembly only spins at clutch depress. Only reason for bushing over bearing is cost. Small tractor like that wont be used as much as a car would. Its a pro/con theory. The bushing only beats the bearing in a dry run scenario. Which can be common on that application.

 

[TheOldHokie]

One thing I would like to point out, the pilot bushing does very little work in this scenario.

JB weld or anything similar would be under very little stress.

Over complicating it by putting a bearing in it, where it's not supposed to go, can cause you some serious issues down the line.

A bearing is not able to take shock loads, where a bushing can, there is a reason they used a bushings on these engines.

I was looking closer at that input shaft assembly. It is a lobro style joint. I can absolutly see now how if it locked up would force side loads like it did. Lobros are cool, but when they lock they don’t move. Generaly you see these in drivetrain multi piece driveshafts.
That input assembly only spins at clutch depress. Only reason for bushing over bearing is cost. Small tractor like that wont be used as much as a car would. Its a pro/con theory. The bushing only beats the bearing in a dry run scenario. Which can be common on that application.

Cost and size. Ford used a 6203 ball bearing for a clutch pilot bearing in every tractor they made from 1939 up through 1975. It was never a problem.

The B7200 ball and cup shaft coupler was not one of Kubota engineering's better ideas, The recirculating ball steering box on those machines is also questionable.

Dan

 

[metricquartz]

I am happy to report back after a very long pause due to a cold garage that my Kubota B7200D is all back together and operating well. The clutch is good and there are no bearing noises at all.
I want to thank everyone for all their help in my repair. Job well done!

 

[IdahoNative]

I came across your post a while ago, after my pressure plate lost a "finger". Glad to hear your tractor is running!

The finger seized EVERYTHING up instantly...it was lodged between the "bellhousing" and flywheel. This was my first time working on a tractor. I ended up removing the engine and replacing a bunch of gaskets, cleaned the carbon out, etc. Yesterday, I buttoned everything up and cranked it over. Nothing but cranking! 2 of the 3 injection pump valves no longer functioned! Dry as the air in Arizona! Today, I dissembled the injection pump and sure enough, they were "rusted" and locked up. My clutch job took too long...meanwhile, the high Florida humidity condensed in the injection pump body and started to rust. I hope to have it running tomorrow!

BTW, how did you ultimately fix yours? Lots of ideas in your post....

 

[metricquartz]

Sorry to hear of your issues with your tractor. With mine I abandoned the crankshaft bearing altogether and had a machine shop cut an area into one side only of the flywheel, The engine side. Then installed a permanently lubricated ball bearing into the flywheel and cut down the propeller shaft to match. It worked out perfectly.
Thank you to all the folks that replied to my post especially The Old Hokie.