Problem with PTO on L 39

Stephenob

New member
Jan 9, 2020
3
0
0
Williamsburg, Virginia
I have an L 39. The PTO turns when engaged, but when under load it does not turn. I have been told that it is the piston, clutch, switch, etc... Can anyone help me to diagnose so I can get this fixed. I don’t want to go immediately to splitting the cab to get to the clutches. Thank a million to anyone who can help me.
 

200mph

Well-known member

Equipment
L4740-3 Cab, FEL, Fnt Snow Blower L2185, LP Finish Mower, LP Rotary Mower
Mar 3, 2017
1,228
61
48
PA
If you don't already have it, I suggest you procure a copy of the WSM and become familiar with the components and theory of operation.

Your Kubota dealer can supply or other.
 

Roadworthy

Well-known member
Lifetime Member

Equipment
L2501 HST
Aug 17, 2019
1,649
526
113
Benton City, WA
The manual would be an excellent starting point. Older PTO units were pretty simple, mechanically engaged like shifting gears. Newer ones have cables, linkages, and some are even engaged via solenoid. Yours is either not staying engaged or or slipping on a clutch somewhere. Adding to the confusion is a possibility of a two stage clutch. It is possibly a simple clutch adjustment but your really need more information.
 

eserv

Well-known member

Equipment
BX24, A1000 Kubota Generator
May 27, 2009
2,140
139
63
Hardisty, Alberta
I have an L 39. The PTO turns when engaged, but when under load it does not turn. I have been told that it is the piston, clutch, switch, etc... Can anyone help me to diagnose so I can get this fixed. I don’t want to go immediately to splitting the cab to get to the clutches. Thank a million to anyone who can help me.
The L39 has a hydraulically activated PTO clutch. there is a small plug on the lever on the side of the transmission that the PTO cable operates. Install a pressure gauge there and run tractor and observe pressure. Should be 0 with PTO disengaged and 330+ with PTO engaged. If the engaged pressure is above 300 the problem is inside the transmission and the tractor will need to be split to repair it. If the pressure is below 300 the problem could still be inside the transmission but you should ensure that the pressure regulator is working properly and able to achieve 330 to 360 psi. Unfortunately if the pressure regulator is not functioning properly you likely still have to split it because the low pressure will have caused the clutch to slip damaging the clutch discs.
 

Stephenob

New member
Jan 9, 2020
3
0
0
Williamsburg, Virginia
OK, I got the WSM and access to the clutch valve and pressure regulator. It is really tight in there and calls for a PT 1/8 connection. Is there a special connection/tool from Kubota that I need before I try it with my tool and possibly strip it? Can I take off the clutch valve plate and not cause problems with the internals? When looking at the regulating valve, I noticed the check plug had been stripped. I tried to easy out it to no avail. If I take off the valve assembly to take out the plug, will I cause any problems internally or need any new parts (gaskets, seals, etc.) when putting it back on? If everything is fine, could the problem be that I need an overrunning clutch coupler because I have an older Kubota?
 

eserv

Well-known member

Equipment
BX24, A1000 Kubota Generator
May 27, 2009
2,140
139
63
Hardisty, Alberta
OK, I got the WSM and access to the clutch valve and pressure regulator. It is really tight in there and calls for a PT 1/8 connection. Is there a special connection/tool from Kubota that I need before I try it with my tool and possibly strip it? Can I take off the clutch valve plate and not cause problems with the internals? When looking at the regulating valve, I noticed the check plug had been stripped. I tried to easy out it to no avail. If I take off the valve assembly to take out the plug, will I cause any problems internally or need any new parts (gaskets, seals, etc.) when putting it back on? If everything is fine, could the problem be that I need an overrunning clutch coupler because I have an older Kubota?
There is a special tool but usually a 1/8 pipe can be made work. If you remove the clutch valve plate you should replace the little pipe ( 36530-27273) in there and the oring (04811-06630). You maybe should be using an overrunning clutch especially if you are running PTO loads with a lot of inertia ( rotary mower etc.) but that isn't the problem if the PTO isn't working right now! It might have contributed to the problem though.
 

North Idaho Wolfman

Moderator
Staff member
Lifetime Member

Equipment
L3450DT-GST, Woods FEL, B7100 HSD, FEL, 60" SB, 743 Bobcat with V2203, and more
Jun 9, 2013
30,224
6,394
113
Sandpoint, ID
If the Plug is stripped, sounds like someone has been messing with it.

The plug will be a 1/8 BSPT, you can use 1/8 NPT just don't over tighten it, or go online and get a 1/8 BSPT to 1/8 NPT adapter.

I use a 1/8" grease gun hose for testing these as it has a 10,000PSI rating.

You can go on Ebay and get a 500 PSI gauge for cheap enough, I have 100, 1000, and 5000.