M9540 Shuttle Shift Weak at Idle

[Cowboy303]

Howdy Guys.

I've got this 2012 M9540 Kubota tractor that has developed an issue with the shuttle shift and clutch. Basically, the clutch is very weak at idle. If you put everything in gear at idle, and let out the clutch it will slowly disengage. If you're on flat ground, it takes about 10 seconds for the clutch to fully lock up. The higher the RPM, the more normal it acts. At 1500 RPM it acts completely normal. It acts the same whether you use the clutch or the shuttle shift for starting out. It's also the same in forward and reverse, though reverse may be ever so slightly better.

At idle, once it finally locks up, if you put some load on it with the brakes, it will disengage again. It's not the clutches slipping, it's as if you hit the clutch. I can get a video of any of this if it helps.

I checked the return springs and all seems to be in place, clutch spool on the side of the transmission appears to be making full travel.

I'm not sure which hydraulic circuit feeds the system, whether it's the main one or the power steering one. But both the loader and the power steering seems very strong at idle.

I hope to get some pressure readings, hopefully that will answer some questions.

Thank you all for any assistance! If there is any more info I can provide please let me know.

EDIT: I also wanted to mention. While I wasn't the one driving the tractor when the issue first occurred, it was my father and he said that it was acting normal then all of a sudden started doing this. Hopefully that helps. Thanks again.

 

[Cowboy303]

Got pressure readings from the forward clutch pressure.

Idle - 67 psi
1000 RPM - 83 psi
1500 RPM - 187 psi
2000 RPM - 282 psi
2600 RPM - 315 psi

The only spec I know of is 299-327psi @ 2600, which is where we're at.

Hopefully this helps.

 

[North Idaho Wolfman]

How many hours are on it?
Has it been worked hard?
What exact model is it, There is 22 M9540 sub models.

 

[Bulldog]

Has the trans fluid been changed?
If so, when was it changed?
How many hrs are on the oil now?
What kind of oil and filters did you use?

 

[Cowboy303]

Thanks Guys!

That tractor has 1755 hours on it.

I'm not sure how to best describe how it's been worked, it basically has 3 jobs, mowing hay, loading hay on trailers and unloading into the barn, and feeding hay in the winter, plus side jobs here and there. Clutch/transmission wise I don't believe it was abused much, I don't typically use the shuttle but instead just clutch it. However this year the mower guy had knee issues so we stuck him on that tractor so he could use the shuttle instead of the clutch... Could be related.

It's a M9540D Serial#89249

The fluid and filters were changed 8 months ago today.
They have 285 hours on them.
The filters are kubota filters, and the oil is the UDT2.

Also, I did more pressure testing, and when you hit the brakes while moving causing the tractor to "clutch", it's just the act of bogging the tractor which lowers the RPM and thus pressure. So whatever is dropping the pressure is causing that as well.

Thanks again!

 

[North Idaho Wolfman]

You have a M9540HD-1, plays a huge role in troubleshooting.

You'll be surprised to know that the clutch pedal and the shuttle, control the same valve.

It's sounding like that valve might need rebuilt, but looking at it, it might not be rebuild-able.

EDIT: Looking it over I would make sure the cables and the connections to the valves are in proper adjustment and moving correctly.

My next choice, sadly, would be that there is either an issue with the clutch pack or the seals for the clutch pack.

Do you have the WSM for that tractor?

EDIT: How is the steering? It shares the same feed line.

 

[Cowboy303]

Good to know, Thanks!

The steering feels completely normal.

I did check over the clutch linkage to make sure it was returning all the way, and it does appear to be. The shuttle linkage is a little harder to see so I couldn't get a great view of it, but I'll see what I can see here in a bit.

No I do not have an WSM. I am very aware of how useful they can be, I have one for most the other machines, but I'm hesitant to buy one for this tractor as I'm not sure how much longer I'll have it. I might just have to brake down and get one.

I stopped at the dealer and he scanned a page of the WSM for me, so that's how I've gotten this far.

Is removing the valving unit as simple as it would seem? Fuel tank, linkages, lines, etc?

Thank you again for your assistance!

 

[Tx Jim]

Have you checked clutch pedal free travel. Spec's listed are for smaller HP tractor but I'm guessing your tractor would be similar.

 

[Tx Jim]

Here's hyd shuttle troubleshooting for lower hp tractor. I think relief valve may be the problem but I think shuttle clutch pack isn't since clutch pack & associated seals will hold 315 psi at higher engine speeds

 

[Farmer Fred]

Good to know, Thanks!

The steering feels completely normal.

I did check over the clutch linkage to make sure it was returning all the way, and it does appear to be. The shuttle linkage is a little harder to see so I couldn't get a great view of it, but I'll see what I can see here in a bit.

No I do not have an WSM. I am very aware of how useful they can be, I have one for most the other machines, but I'm hesitant to buy one for this tractor as I'm not sure how much longer I'll have it. I might just have to brake down and get one.

I stopped at the dealer and he scanned a page of the WSM for me, so that's how I've gotten this far.

Is removing the valving unit as simple as it would seem? Fuel tank, linkages, lines, etc?

Thank you again for your assistance!

Did you ever find out what exactly was wrong with the clutch on your m9540. I’m having a similar problem on my 9540.