L4150DT Hydraulic Shuttle "slipping"

[gpsmatty]

I just picked the tractor up, PO had health issues, and it sat for five years until he passed away, and I purchased it from the estate. I changed the oil, flushed the fuel, and put a new battery in, and the tractor fired right up (huge relief). The 3 point lift works bucket lifts and has enough power to lift the front wheels of the tractor, but it won't go anywhere unless in the lowest gear. The best way I can explain it is it feels like it's slipping. My automotive experience and knowledge tell me it doesn't quite feel like a burnt-up clutch.

At this point, I feel like I've read everything there is to read on similar issues, and this:

https://www.justanswer.com/agriculture-and-farm-equipment/enhty-l4150-kubota-hyd-shuttle-want-move-forward-reverse.html

That site sucks, and there is no resolution to his problem, but that's precisely what I am experiencing.

It's raining today. Otherwise, I would be out working on it, but my first course of action is to replace the hydraulic filter, and look for some kind of adjustment on the shuttle valve.

Curious what else I should look out for, and what the best way to definitively figure out if it's the clutch or not.

 

[gpsmatty]

I'm thinking it has something to do with 4 and 7 in the first drawing. Or 17, the flow priority valve?

 

[gpsmatty]

I had someone watch the PTO, and when it starts slipping, the PTO doesn't turn, and the tractor doesn't go anywhere, leading me to believe it's the single disk clutch and hopefully has nothing to do with the hydraulic clutch.

 

[big bubba]

not sure my hyd shuttle is the same as your model. i started experiencing the same problem, seemed as though it was not fully engaged, etc. there is a turnbuckle affair on mine that you can fine adjust the hy shuttle cable for either direction. mine is on the column.
so i'd try to adjust the hyd shuttle cable 1st. that didn't solve the problem on mine so i took it in. the hyd shuttle cable was sticking. access to it is a chore (have to drop tank, etc). wish there were some lube points on the cable. cost me 1k repair bill. hopefully yours can be remedied by adjustment. but sitting that long, the cable might be sticking
good luck

 

[gpsmatty]

not sure my hyd shuttle is the same as your model. i started experiencing the same problem, seemed as though it was not fully engaged, etc. there is a turnbuckle affair on mine that you can fine adjust the hy shuttle cable for either direction. mine is on the column.
so i'd try to adjust the hyd shuttle cable 1st. that didn't solve the problem on mine so i took it in. the hyd shuttle cable was sticking. access to it is a chore (have to drop tank, etc). wish there were some lube points on the cable. cost me 1k repair bill. hopefully yours can be remedied by adjustment. but sitting that long, the cable might be sticking
good luck

I went on ahead and checked it again, on my model it's on the backside of the firewall and has a rod going directly to it. I disconnected the Rod and manually moved the shuttle to make sure it was fully engaging and unfortunately there was no change. The fact the PTO turns off when it starts slipping leads me to believe it's the main clutch. What concerns me though is when it's cold it wants to barely move at all and the second thing is I cant smell any burning clutch.

 

[the old grind]

If 17 sticks flow will go through open center valves to tank, no pressure for HST but stalling a cylinder (curl up & hold) should divert full flow to HST. If it doesn't I suggest 17 isn't the problem. I also think if it was 4 o 7 one direction wouldn't work, but both?

 

[gpsmatty]

If 17 sticks flow will go through open center valves to tank, no pressure for HST but stalling a cylinder (curl up & hold) should divert full flow to HST. If it doesn't I suggest 17 isn't the problem. I also think if it was 4 o 7 one direction wouldn't work, but both?

I agree, after further diagnosis and research, I believe it's the single dry clutch between engine and transmission. I think this because when traveling forward and it "slipping" the PTO is not turning.

 

[the old grind]

Could it be as simple as checking an adjustment on the dry clutch? Fingers crossed.

 

[gpsmatty]

Could it be as simple as checking an adjustment on the dry clutch? Fingers crossed.

I removed the rod altogether so there was no "adjustment" pressure on it and it was no different. I did notice that if I tap the clutch while moving forward it disengages with just tapping the clutch as if there's no play, and that was even after checking adjustment. At this point, I've got a clutch kit on the way and am going to change it out.

 

[rbargeron]

I removed the rod altogether so there was no "adjustment" pressure on it and it was no different. I did notice that if I tap the clutch while moving forward it disengages with just tapping the clutch as if there's no play, and that was even after checking adjustment. At this point, I've got a clutch kit on the way and am going to change it out.

I had a L4150 with hydraulic shuttle for a few years - one of the models Kubota built its reputation on in the U.S. - great tractor. (I now have its brother L5450)

The symptoms say its the main clutch that needs adjustment, not the shuttle valve linkage.

There should be about 1" of pedal free play before the clutch starts to feel heavier (starting to disengage). If tapping the clutch pedal stops drive and pto, the PEDAL linkage under the left floorboard needs adjustment.

The turnbuckle 030 in the diagram needs to be adjusted so there is 1" free pedal play. That should restore motion with pedal up.

You may find that with the clutch pedal correctly adjusted, the pto will no longer disengage with the pedal full-down. If so, post back and we'll go from there. Best luck - and Happy New Year ! Dick B