Kubota B1550hst clutch install

[hanks]

Sold a truck and took a Kubota B1550hst in the trade. Several bolts between clutch housing and flex plate were broken off,flex plate cracked,pilot bushing wallowed out,pilot shaft damaged,clutch and pressure plate damaged by using fel without having frame braces. All new parts on hand and reassembly underway. Through research I found several tractors that suffered similar damage from blower,hoe and fel use but noone addressed an issue I have. After clamping new flex plate to housing (plate not bolted to engine) there's a gap between plate and housing from 10 oclock to 2 oclock. 1/16" at 10 and 2 with 3/32" 11 to 1. Flex plate confirmed flat laying on test plate so apppearantly housing is bent. No way I'm going to heat or beat housing in attempt to bend back and I believe pulling it togeather with bolts can crack flex plate or at best preload stress on plate and operational stress would cause plate to crack. I've considered shims so that bolts can be torqued down but my concern is prop shaft running out of alighnment. If I had some way to referance where shaft is alighed i could shim to maintain it. I'm away shaft only spins inside bushing when clutch pedal is pressed but misalignment undoubtedly has an effect,how much is the question. Oilite bushing turned 0.130 oversize od to compensate for wear in crankshaft.
Have you ran a prop shaft off center and what was the result?

 

[JWR]

An HST has a clutch pedal ??

 

[4570Man]

An HST has a clutch pedal ??

Yes.

 

[JWR]

Where ?

 

[ptsg]

Where ?

On the left. Used to engage/disengage the PTO.

 

[JWR]

On the left. Used to engage/disengage the PTO.

Thanks PTSG. Understand. I'm sure that is a clutch, just never heard it called one.

 

[ptsg]

Thanks PTSG. Understand. I'm sure that is a clutch, just never heard it called one.

It was common on older HST tractors. It's actually a regular dry clutch, the same one that would go on the gear model. Technically when you press the pedal, it would also stop the HST from working.

 

[rScotty]

It was common on older HST tractors. It's actually a regular dry clutch, the same one that would go on the gear model. Technically when you press the pedal, it would also stop the HST from working.

Yep. Our Kubota M59 has a clutch pedal as well as the HST+ tranny. No idea why, but on the parts diagram the clutch looks just like a standard dry clutch on any old 50 to 80 hp tractor with a manual transmission. I haven't looked at the parts manual to confirm if the parts are standard but it works just like any dry clutch.

Push it down and no power gets past the bell housing. Like other clutched tractors, you have to push it down to override the safety switch to start the engine. In 1000 hours, that's all we've ever used it for.

The weird thing about the clutch pedal is that having it not only makes no sense, but it caused Kubota to move both steering brakes to the right side next to the HST control pedal. Takes some getting used to.

In 2016 the M62 with emissions control gear replaced the M59. Very similar machine with the same engine and tranny. I looked at one and if I remember right it did not have the clutch pedal. I think the foot steering brake pedals were in that location instead of a clutch pedal.

rScotty

 

[rScotty]

Sold a truck and took a Kubota B1550hst in the trade. Several bolts between clutch housing and flex plate were broken off,flex plate cracked,pilot bushing wallowed out,pilot shaft damaged,clutch and pressure plate damaged by using fel without having frame braces. All new parts on hand and reassembly underway. Through research I found several tractors that suffered similar damage from blower,hoe and fel use but noone addressed an issue I have. After clamping new flex plate to housing (plate not bolted to engine) there's a gap between plate and housing from 10 oclock to 2 oclock. 1/16" at 10 and 2 with 3/32" 11 to 1. Flex plate confirmed flat laying on test plate so apppearantly housing is bent. No way I'm going to heat or beat housing in attempt to bend back and I believe pulling it togeather with bolts can crack flex plate or at best preload stress on plate and operational stress would cause plate to crack. I've considered shims so that bolts can be torqued down but my concern is prop shaft running out of alighnment. If I had some way to referance where shaft is alighed i could shim to maintain it. I'm away shaft only spins inside bushing when clutch pedal is pressed but misalignment undoubtedly has an effect,how much is the question. Oilite bushing turned 0.130 oversize od to compensate for wear in crankshaft.
Have you ran a prop shaft off center and what was the result?

Hank, sorry to contribute to the thread drift. I'll try to get it back on track.

I believe what you are attempting to fix was a common problem for loaders without a full length
frame. All the bending stress was carried by the bell housing. Those housings were often cast and usually broke rather than bent. Common fix invoved a junkyard tractor with a good housing. I never heard of one just bending. But bending would account for the problems you have.

Hmmm.... I may be offbase, because I don't know the B1550. I'll go take a look at the parts book on Messick's site and see if I come up with any thoughts.

 

[rScotty]

Any of this look familiar? Is your "flex plate" what I would call the "Pressure Plate 020"?