Clutch or other?

[bobby beauch]

Hi there,

I have a 2021 L3901 manual with 115 hrs. Starting up the tractor and I got the P0336 code. I cleared the error.
The engine sounds great and all the hydraulics work fine and the PTO works, but when i put it in gear it barely tries to move - a very slight pull (on a decline is goes - just barely and it doesn't matter what gear I'm in...same feel and just crawling like 1 mph). The forward/reverse, both speeds, and the 4 wheel drive all engage from what i can tell on the exterior levers.
To see if it's a clutch issue I turned the throttle on high and put it in 4th gear to see if it would kill the engine and tell me maybe it's the clutch. It didn't kill the engine so I think it's the clutch. Just seeking wisdom if I'm missing anything or any trouble shooting y'all can think of before taking it all apart to get to the clutch. Thank you in advance!

 

[cthomas]

Try the search function multiple answers, did you stall the engine?

 

[North Idaho Wolfman]

Do you have the parking brake set?
If the clutch is that fried, the pedal should go down almost all the way before disengaging!

 

[bobby beauch]

Thank you. I don't think i stalled the engine. The engine sounded find but there wasn't a lot of power when i drove it the last time before I got the error code. I was shifting up gears to get more power driving it and it didn't make a difference. The engine sounded fine. I think the P0336 code can be for too low rpms, but I'm not the coldest beer in the fridge

 

[bobby beauch]

Do you have the parking brake set?
If the clutch is that fried, the pedal should go down almost all the way before disengaging!

Thanks for the pointer, I'll play with and see. It's hard to tell if/when it engages or not as it doesn't really engage and go -side note the clutch has always had a very heavy clutch to engage. Thanks again. Parking break is not engaged.

 

[Russell King]

The use of engagement with clutches can be confused by how it is meant…
I think NIW used disengagement with pedal movement down and you used engagement with pedal movement up which are both proper uses but are different movements. I don’t think you answered NIWs question correctly but I could also be mistaken.

How hard is it to push the pedal down and do you feel any secondary pressure on the downward movement? Where in the pedal movement does the pressure get added? You described it as heavy but I can interpret that as engaging quickly or as grabbing

 

[lugbolt]

check the pedal free play. There should be about an inch of freeplay, in other words if you move the pedal by hand from all the way at the top most position, you shoud be able to fairly easily push the pedal down about an inch. If not, it's probably gonna need a clutch. The disc wears and the pedal free play goes away. I'm assuming it's a gear drive and has a loader on it.

P0336 is a 'crankshaft position sensor abnormality' according to kubota. It can be set if you LUG the engine way down, like below about 550 rpm, for any length of time (IIRC 5 seconds or more). ECU expects to see a certain speeding up and slowing down of the crankshaft. When a cylinder fires, the crankshaft will speed up, then it slows down until another fires. Every 240 degrees of crankshaft rotation there is a firing event. When you lug the engine, that speeding up/slowing down is amplified dramatically and the ecu sees this as "abnormal" and sets a code. That's the most common cause. Second most common is a sensor that has flywheel and/or pressure plate material stuck to the magnet which is usually a function of a burnt up clutch. The sensor has a magnet in it and any metal dust of filings will stick to the sensor which can mess with the signal it sends to the ecu.

 

[bobby beauch]

Do you have the parking brake set?
If the clutch is that fried, the pedal should go down almost all the way before disengaging!

Can't tell you how much I appreciate all the wisdom. All signs point to the clutch.
I'm working with my buddy who's a tractor mechanic, think we've got the disassembly/splitting figured out minus the front end drive shaft. I've searched all over for diagram and youtube videos and haven't found the instructions and am worried we'd damage it. Thanks for anything you can share! (L3901 2021 DT).

 

[Fordtech86]

Can't tell you how much I appreciate all the wisdom. All signs point to the clutch.
I'm working with my buddy who's a tractor mechanic, think we've got the disassembly/splitting figured out minus the front end drive shaft. I've searched all over for diagram and youtube videos and haven't found the instructions and am worried we'd damage it. Thanks for anything you can share! (L3901 2021 DT).

https://www.kubotabooks.com/AutoIndex/index.php?dir=Tractor%20Owners%20Manuals/&file=L3301%2C%20L3901%2C%20L4701%20Workshop%20manual..pdf

Link to workshop manual

 

[North Idaho Wolfman]

The best prints of the parts are here: https://apps.kubotausa.com/illustrated-parts/
Propeller shaft is easy.
Pull the 3 bolts (50) & (90)
Push tube (40) forward, It will slide inside of (70)
That will expose the coupler (20) in the rear.
Have one front wheel off the ground turn shaft (10) till you can drive out the roll pin (30) in the coupler (20) then the coupler will slide forward allowing you to remove the shaft and cover tubes.