3 point hitch speed control 'frozen'

[ctgoldwing]

Now that I have been using my 'new to me' L3800 for a while I've started discovering things that weren't 'excellent condition' as advertised. No buyers remorse here just fixing, adjusting replacing or servicing what I find. Which brings me to the 3ph speed control.
It is really frozen in place. I tried putting a channellock type wrench on it and managed to get one not so great sounding squeak out of it. I stopped there. Something tells me a snapped valve stem will be worse than what I have now. . .
Since the speed of the 3 point is fine this is just one of those things I have to fix. Any ideas why it might be locked? The tractor is a 2013 and had 264 hours on the clock when I bought it a couple of months ago. It does look like it spent some time outside (paint is slightly faded) but no significant rust that I see anywhere.

 

[CoyPatton]

I assume you are talking about the valve under the front of the seat. Mine is not a kubota, but mine is a turn knob valve. It should turn with slight resistance as you opening/closing a valve. My guess is it was wide open allow a rapid return of fluid as the 3ph is lowered. Thus my guess is your squeak was forcing it to turn past its build in stop. Try turning it the opposite direction when fully closed, it prevents the 3ph from lowering (a caution, trying to raise the 3ph can cause damage on some tractors). This is more a storage option or an option when the lift arms are removed. The bounce with it closed and transporting a heavy implement can also cause damage on some tractors.
If a different item you are turning please post pictures.

 

[ctgoldwing]

No CoyPatton, that's the one. I did try both directions, one resulted in the squeak - not a good squeak either. I tried penetrating oil but frankly if penetrating oil can get by the stem seal I have bigger problems.

 

[Roadworthy]

You want to know why the three point valve might be locked? It might be because it's a Kubota tractor whose valve wasn't adjusted often enough. They have a tendency to freeze in place if not run through their adjustment from time to time. I have no idea why, they just do. I have no idea how difficult they are to replace either. I would hope it's not a spit the tractor type of repair but you should check the parts breakdown or a knowledgeable mechanic familiar with the issue.

 

[ctgoldwing]

You want to know why the three point valve might be locked? It might be because it's a Kubota tractor whose valve wasn't adjusted often enough. They have a tendency to freeze in place if not run through their adjustment from time to time. I have no idea why, they just do. I have no idea how difficult they are to replace either. I would hope it's not a spit the tractor type of repair but you should check the parts breakdown or a knowledgeable mechanic familiar with the issue.

Could very well be it was never adjusted. As far as I know the previous owner used it exclusively for hauling wood. I even commented when I 1st looked at it that the 3ph looked like it had never seen an implement. I'll take a look at the exploded view of the valve. If it looks like a reasonable project I'll see how much damage I can do.
Thanks

 

[Fallon]

Not sure if its common, but I have seen a good few posts on this issue over the years. I think generally it was sized from lack of use. A little gunk & corrosion. Often penetrating oil & careful application of force got it free. A couple had to pull the tranny top plate though.

 

[Tinhack]

Mine is on the side of the pump housing section in front of the differential. It was frozen solid when I got my Ford. It had a plastic knob which was already cracked so I finished it off by oiling and tapping it back and forth until loose. After that I could access the retaining screw to remove the balance of the knob. I then made a new lever to replace the knob. I make it a point during lubing to put a drop of oil on the shaft where it enters the housing and move it back and forth. It's stayed free for the 12+ years I've had the tractor.

I always keep it on fast but I'm anxious to try it out on slow for the T-n-T remotes I'm adding. As I understand it on the Ford, It simply opens a small relief port for the hydraulic circuit flow. The lift force is still there, it's just slower to act.

 

[s219]

Mine seized up. I am pretty sure I had set it once when the tractor was new then forgot about it for many years until I got a ballast box (which needs a much slower rate or it will shake the whole tractor when lowering). I kept soaking the area around the knob shaft with penetrating oil, and eventually it loosened up. Been fine since. I probably adjust it 3-4 times a year at most now.

 

[madpogue]

Pardon the necro-post. I'm dealing with this same issue on an L2501 HST that I'm maintaining. Dagnabbit I shoulda taken a photo... the knob shaft goes into the hydraulic box with a two-bolt "cover". Wondering if I should remove that to get in there with PB Blaster to get the knob/shaft turning again. Maybe it's the cover that the shaft is "frozen" to. Just not sure if removing it will result in a big mess of little spring-loaded parts and/or buckets of hyd fluid flying out. Or will I blow any gaskets/o-rings?

Maybe just to be conservative I should start with just shooting the PB at the point where the shaft enters the gearbox. Then consider removing those bolts only if that doesn't work.

 

[madpogue]

Update - With this model, the shaft angles downward into the trans case. So I drizzled some PB Blaster on the shaft, let it drizzle down for a few minutes, then took a vise-grip to the shaft. Took some wrestling, but it gradually got easier to turn, to the point that that it now can be turned by hand with the knob.

Pro tip - put the vise-grip on the shaft, not the knob itself as others have done. It'll nick up the shaft, but it won't crack the knob as has happened to others.