M8580 Slow to go

AllsOFsome

New member

Equipment
M8580
Apr 7, 2021
6
0
1
Oregon
I've had this M8580 for a few years and I love it. I use it mostly for hauling rock and hay bales. Recently after a long day of buckets of gravel the transmission is suddenly slow to react. Both forward and reverse, high and low. I figured it was just a fluid issue and changed out the hydro and filters. No luck. Its got a ic shuttle shift. Now I'm wondering if it's the proportional valve. Any insight would be greatly appreciated.
 

Dave_eng

Well-known member
Lifetime Member

Equipment
M7040, Nuffield 465
Oct 6, 2012
5,239
1,022
113
Williamstown Ontario Canada
There are two different shuttle arrangements.

Can you please clarify which you have. You state ic shuttle but I do not know which you have.

forum M8580 shuttle.jpg


Dave
 

AllsOFsome

New member

Equipment
M8580
Apr 7, 2021
6
0
1
Oregon
There are two different shuttle arrangements.

Can you please clarify which you have. You state ic shuttle but I do not know which you have.

View attachment 58174

Dave
It has a cab so that's going to be a power shuttle I'm thinking. Is it a power take off issue? The tractor will go in both directions and in all gears. It's just slow to take off. Thanks for replying and getting involved

Ryan
 

Dave_eng

Well-known member
Lifetime Member

Equipment
M7040, Nuffield 465
Oct 6, 2012
5,239
1,022
113
Williamstown Ontario Canada
Ryan
From looking at the WSM I see the operating pressure for the IC shuttle is controlled by the pto clutch hydraulics.

Does your pto engage properly or is it slow to lock up?

forum M8580 shutttle.jpg


forum M8580 shuttle 2.jpg

forum M8580 shuttle 3.jpg


I have not personally worked on this model. Checking pressures and adjusting them if out of spec does not look too difficult.

Digging into the transmission internals does not look like a place to go if you do not have Kubota training.

The M7040 series with hydraulic shuttle does not have a clutch in the traditional sense of the word with a disc being pressed against the engine flywheel. Instead there is a coupling device that connects the flywheel to the transmission shaft and the clutch pedal is just using the shuttle clutch packs when you depress the clutch pedal.

The M8580 seems to still use a traveling clutch in addition to the shuttle clutches. Double check that you have adequate free play in your clutch pedal and that the symptoms you are experiencing are not from a worn out clutch.

forum M8580 travelling clutch.jpg


Dave
 
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AllsOFsome

New member

Equipment
M8580
Apr 7, 2021
6
0
1
Oregon
The pto is slow to engage. I will test the pressures on the proportional valve and get back to you..I suspect this is the issue. Thanks!
 

AllsOFsome

New member

Equipment
M8580
Apr 7, 2021
6
0
1
Oregon
Ryan
From looking at the WSM I see the operating pressure for the IC shuttle is controlled by the pto clutch hydraulics.

Does your pto engage properly or is it slow to lock up?

View attachment 58822

View attachment 58823
View attachment 58825

I have not personally worked on this model. Checking pressures and adjusting them if out of spec does not look too difficult.

Digging into the transmission internals does not look like a place to go if you do not have Kubota training.

The M7040 series with hydraulic shuttle does not have a clutch in the traditional sense of the word with a disc being pressed against the engine flywheel. Instead there is a coupling device that connects the flywheel to the transmission shaft and the clutch pedal is just using the shuttle clutch packs when you depress the clutch pedal.

The M8580 seems to still use a traveling clutch in addition to the shuttle clutches. Double check that you have adequate free play in your clutch pedal and that the symptoms you are experiencing are not from a worn out clutch.

View attachment 58826

Dave
After finding the right fitting that fits my oil pressure gage, it looks like my pressure on the relief valve is 260 in forward and reverse. The clutch pedal is also in tolerance. Other than that I'm not to sure
 

AllsOFsome

New member

Equipment
M8580
Apr 7, 2021
6
0
1
Oregon
After finding the right fitting that fits my oil pressure gage, it looks like my pressure on the relief valve is 260 in forward and reverse. The clutch pedal is also in tolerance. Other than that I'm not to sure
 

LaneMaz

New member

Equipment
M8580
Feb 17, 2022
1
0
1
Canada
After finding the right fitting that fits my oil pressure gage, it looks like my pressure on the relief valve is 260 in forward and reverse. The clutch pedal is also in tolerance. Other than that I'm not to sure
did you ever figure out the problem? My m8580 is doing the very same thing.
 

nick addo

New member

Equipment
kubota
Jul 5, 2024
7
0
1
australia
i have a 1995 m8580 kubota and it was getting harder to find reverse so we changed the hydraulic oil filter
and found a chunk of a bearing race anyone know where it might have come from as i have not yet found a lead on this issue
 

Tx Jim

Well-known member
Lifetime Member

Equipment
M7040 HDC-1,JD 4255,Ford 6700
Apr 30, 2013
1,202
128
63
Coyote Flats,Texas
I think Peter made a mistake on Tractordata. Only Kubota parts catalog I can locate for M8580 with cab has Synchro-shuttle not hyd shuttle. This parts catalog shows a dual speed hyd clutch that could be cause for slippage
 

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nick addo

New member

Equipment
kubota
Jul 5, 2024
7
0
1
australia
i have found the issue one of the main support bearing has come out of either the transmission case or the bearing support causing it to eat away at both one of the gears and the case of support
does anyone know if i can repair without splitting it