Mid-PTO lever drifting

[Forge]

Hi all,

The mid-pto lever on my B7800 is drifting to neutral after a few moments of mowing using my MMM RC72. As the engine warms up it does it more frequently.

I can't help thinking its something simple within the MMM pto drive but any thoughts/advice on this would be much appreciated.

Many thanks

 

[Kubota Newbie]

That (regardless of make and model) is often a symptom of a worn gear or spur gear. The gear wear causes end thrust on the sliding gear and pushes it toward the neutral position. It can also be a symptom of the detent ball not properly engaging its "in-gear" detent position. The latter is the easiest and normally cheapest to fix. There scould be an audible "click" when you engage the pto with the tractor turned off. You should also be able to feel the detent engage its slot/hole.

 

[Forge]

Thanks. I had the whole detention ball issue on a previous tractor. An easy fix. My dealer thinks something is going on with a D clip in the main gear housing which sounds counter-intuitive. Unless a Main gear is worn but I should see this if I remove the PTO drive. The tractor only has 400 hours which makes the whole worn issue seem surprising.

If anyone can shed light on how the mid pto actually works that may help.

Thanks

 

[Forge]

The census is that the detente is not properly engaging. The good news is that it sounds like a simple fix. The bad news is that the detente is in the main gearbox so a split is required to fix. The easiest solution appears to be an external detente - namely stopping the drift with a small bracket that holds the mid-pto lever in place.

This detente seems like a bad design issue. I expect better from Kubota. Perhaps next time they will put the detente where it's easy and inexpensive to access - in the pto drive! (Or perhaps they already have....).

 

[Kubota Newbie]

Hmmm... According to the Kubota on-line illustrated parts diagram your spring detent for the mid-pto lever is located in the top of the mid-pto "add-on" gear case on the bottom of the transmission. Looks to be held on with 4 bolts, the lever shaft is held in with a locating pin that slides out the top and the spring detent is under a small plug just inboard of that. Probably will need a new gasket (or some good silicone) and should replace the o-ring seal on the shaft while you're at it. Hopefully it's just a broken spring or stuck detent ball.

 

[Forge]

Thanks Newbie. I hope you are right! I couldn't tell whether it was in or out. The dealer thought in. Still, only one way to find out!

 

[Forge]

Thanks again, Newbie. You are right. Just got my parts manual and can see it clearly. The shift fork for the rear pto is in the transmission case and also uses a détente and that one works fine.

 

[Kubota Newbie]

Hey, ya gotta love the on-line availability of parts diagrams. They've saved me a bunch of work and money on everything from appliances to my pick-up.
Good luck!