L3800 HST Pto Issue

[jamesr in oregon]

Hello, new member just picked up a L3800 that needs some work and hoping to pick the collective brain trust to help diagnose more fully before moving forward with Pto repair and possibly splitting the tractor. When PTO is engaged terrible clattering noise but pto shaft is turning when clutch is released as long as tractor is in neutral. I believe the clutch engagement plates and possibly engagement fork/rod are damaged and must be replaced. HOWEVER, what seems odd to me but may be normal is the fact that when the tractor is in gear and the pto is engaged upon letting the clutch out fully the tractor dies. It acts as though now the drivetrain is bound up or carrying too much load on the engine.
I should mention that this is all at fairly low RPM's ( maybe 1800) since the sound is so bad I am afraid of releasing the clutch at higher RPM's with the Pto engaged. Is this normal or is there another issue I need to research before jumping in to repair the Pto issue. I just assumed the drive components would be seperate from the PTO and Pto being engaged should not affect drive engagement/operation. If the Pto is not engaged the tractor drives, shifts, and operates normally, including differential lock and 4 wheel drive. I appreciate any education or possible test procedures to diagnose that anyone can give me on this issue.

 

[North Idaho Wolfman]

Do you have the WSM (aka Service Manual)?

The PTO is directly driven off of the HST input shaft so any issue with the PTO will effect the HST.

The HST input shaft is in yellow.
The PTO output shaft is in green.
The issue you have is most likely in the gears or bearings in RED circle.

 

[jamesr in oregon]

Yes, I do have the WSM. Maybe its my comprehension but looking thru it didnt really show me what might be causing this apparent conflict between the drive and Pto systems. All the threads I have read addressing this PTO issue have not mentioned this affecting the drive system so I dont think its normal. Any thoughts or W.A.G.'s are welcome. Thanks for replying

 

[North Idaho Wolfman]

Yes, I do have the WSM. Maybe its my comprehension but looking thru it didnt really show me what might be causing this apparent conflict between the drive and Pto systems. All the threads I have read addressing this PTO issue have not mentioned this affecting the drive system so I dont think its normal. Any thoughts or W.A.G.'s are welcome. Thanks for replying

No it's not "normal" something is wrong!

 

[jamesr in oregon]

Thanks Wolfman, that diagram along with your explanation helps alot in that it helps narrow down the components I need to look at. Much appreciated.

 

[old and tired]

....When PTO is engaged terrible clattering noise but pto shaft is turning when clutch is released as long as tractor is in neutral...

Do you have an implement that you can attach to the PTO? The fact that the PTO spins may not mean that it can handle a load. If you hook up a mower, it might not have the power to spin it and more noise might be the result!!!

If you do split the tractor, please document what you find out...

 

[jamesr in oregon]

Do you have an implement that you can attach to the PTO? The fact that the PTO spins may not mean that it can handle a load. If you hook up a mower, it might not have the power to spin it and more noise might be the result!!!

Good point, it sounds and feels like it would not engage enough to handle a load. Also, when the tractor is shut down and the PTO is disengaged turning the shaft by hand results in random contact gear grinding noise as well. I sold all my implements when I sold my last tractor and will need to replace now.
Thanks