3910 PTO runs constantly

BondoBuilder · Oct 4, 2009

Hey Guys! I picked up this 1989 3910 about a year ago, with an INDEPENDENT PTO. On occasion, as soon as I start the tractor, the PTO will be running while the lever was in the disengaged position. After a few minutes it would shut off. It has done this about three times.

Today I started up the tractor and the PTO was spinning, and did not stop for about 20 minutes. It seems to be spinning full torque- no, I'm not stupid enough to grab it!

I checked the hydraulic fluid and it was 3 gallons low!! The brakes leak more than I thought...

I started up the tractor again, following the top off, and it was spinning again. It shut off after about 10 minutes.

Is the regulator stuck open, or are the clutches bad, or something else?

On a scale of 1-10 how complicated is this to fix. My skill level is probably 5-6ish...

Thanks in advance!

Hooked_on_HP · Oct 4, 2009

Does it spin with somthing attached to it. Sometimes the oil being thick will cause the shaft to spin untill the oil warms up with no load on it. I wouldn't be concerned unless it was spinning a implement when disenguaged.
Bill

Birdhunter1 · Oct 4, 2009

My 3910 with 1600 hours on it has done it for the last four years I've owned it, no leaks and the clutch is in good shape. A neighbor of mine also has one that has done it since he bought his a few years old, both his and mine will not do it once you hook something up to it and for what it's worth I have grabbed the shaft on mine and stopped it, but I don't know that I'd recommend it.

BondoBuilder · Oct 5, 2009

Well this is good news then. I was worried, it has never done this before.

Right now, the only way to start my tractor is to pull it- I'm working on the wiring...

I didn't have time this weekend to hook up the baler (the only implement I could shut the tractor off for and pull start with, without dragging).

When I start it this weekend, if the PTO is running, I'll try to grab it with a loose hand- hopefully I don't lose an arm.

Thanks guys!

jinman · Oct 5, 2009

BondoBuilder said:
When I start it this weekend, if the PTO is running, I'll try to grab it with a loose hand- hopefully I don't lose an arm.

May I suggest that instead of using your hand, you substitute a short piece of lumber like a 2x4 or even a shovel handle. I firmly believe in keeping my hands away from rotating PTO shafts. If you can't stop it with a 2x4 or shovel handle, you wouldn't want to put your hand on it anyhow.

BondoBuilder · Oct 5, 2009

jinman said:
May I suggest that instead of using your hand, you substitute a short piece of lumber like a 2x4 or even a shovel handle. I firmly believe in keeping my hands away from rotating PTO shafts. If you can't stop it with a 2x4 or shovel handle, you wouldn't want to put your hand on it anyhow.

After thinking about it for 5 seconds, I thought I'd better not grab it bare handed.

I think I'll take your advice and angle a 2x4 against the shaft and the drawbar. Thanks for looking out for me

Birdhunter1 · Oct 5, 2009

Like I said, I did it but don't recommend it.

MikesTractor · Oct 6, 2009

The 3910 used a brake that pressed against the pto clutch housing to stop the pto from turning. The brake releases as you move the lever forward to engage the pto. It sounds like the brake might be a little weak. Friction can cause the pto shaft to turn.

This was not uncommon on Fords with independent pto. Like Hooked_on_HP said, I wouldn't worry too much unless it started running equipment when it is off.

Just be careful around it, don't grab it with your bare hand, and try to hook/unhook equipment with the engine off. Once you get the wiring repaired, this shouldn't be a problem.

Hope this helps,
Mike