Hydrostat/pto problem

[harpo]

Hi, I've got a JD 4300 w/ hydrostat drive. I loaned it to my brother to chip up some limbs with the pto driven chipper. While he was operating it the pto quit working, then shortly afterward the Hydro drive (both forward and reverse) quit working.
Does anyone know what kind of problem I have?
The only thing I know he was doing wrong was not keeping the pto drive shaft to the chipper level while he was operating the chipper(he was just setting the chipper on the ground).
Thanks for any help.

 

[kennyd]

My first thought would be to check the seat safety switch or the range selector safety switch. Short of that being OK I think we need more details...

Does the engine start OK?
Does the engine bog at all when trying the hydro pedals?
Is there any "feedback" in the hydro pedals?
Does the PTO light light?
Can you turn the PTO shaft by hand?

 

[harpo]

I don't have the tractor to check all of these things right now. My brother is hauling it over to my house tomorrow.
I do know that the engine starts and runs OK. No bogging when depressing the pedals. Not much feedback in the pedals, they mash to the floor pretty easily.

 

[RogerH]

Take a look at the coupler on the engine flywheel. It will be a disk with a hub that connects to the hydro shaft. It is possible that this coupler failed and is not even turning the hydro shaft. Put a paint or marker dot on both the coupler hub and the hydro shaft, start the tractor and see if both are turning. Using a mirror and flashlight should enable you to do this easily and safely.

 

[harpo]

Thanks for the ideas. I am still waiting to get the tractor back. I should be able to check some of these things this weekend. I'll post back in a couple of days, after I have a chance to look at the tractor. Thanks.

 

[harpo]

Got my tractor back today and checked the engine to tranny connection. That appears to be the problem, thanks RogerH ! There were some chunks of black rubber that I pulled out of the hub and the transmission shaft is not turning. So now I guess I just need to repair this connection and hope there is not something more serious that caused the failure. Is this a difficult repair? What is the procedure? Thanks again.

 

[RogerH]

Fixing this problem is not trivial. The coupler will have to be replaced and that involves splitting the tractor at the engine to transmission housing joint. It has been several years since I did this, but briefly you have to support both the engine and tranmissions sides of the joint. I recall the mechanic I worked for had some special stands that we bolted on to each half. The engine to transmission bolts will need to be removed along with any linkages, hydraulic lines and I think wiring harness that spans the joint.
I seem to recall that with all the right tools and the other guy that had done this before, it took two of us about 4 hours to do the job.

 

[harpo]

I suspected it would involve splitting the tractor, though I was hoping it wouldn't. I went to my dealer yesterday to buy the new part, but they could not find it on their computer or in their cataloges. Wants me to bring it in so they can put their eyeball on it.

 

[dirtworksequip]

harpo, what if anything do you suspect may have caused the failure? Or has this been a problem with the ehydro's?

Sincerely, Dirt

 

[harpo]

Dirt, the only thing I can think of that caused the failure is a heavy load on the pto. I don't think this has been a problem with eHydo's in general. My dealer has never replaced one of these couplers. I just got lucky I guess. My tractor only has 320 hrs on it, so I don't think it is age related.
I could use some help finding this part (the coupler between the engine and transmission on a JD 4300). What is the correct name for this part? I can't find it at JD Parts online.