NH 1920 Two-speed PTO option: How can I tell if my tractor has this?

grcutter · Nov 30, 2022

I just acquired a 1997 NH 1920 which has a PTO grinding issue (which I will ask about in a later post).

The repair manual for the 1920 (page 319) states that some models have an optional two-speed PTO but the owner/operator's manual makes no mention of this.
How can I determine if my tractor has this optional two-speed PTO and how is it controlled?

Here is the text from the repair manual:

From figure 4, it looks like the Sliding Gear(2) would move in two directions with Neutral being in the middle.
My tractor appears to only two positions for the PTO level so maybe it does not have this option.

Thanks in advance!

Sincerely,
Dan

MTGreen · Nov 30, 2022

I would imagine that was not a common option as there are few 3pt implements designed for 1k RPM that will run on that small of a tractor. But from the mechanism diagram, your PTO lever that actuates that sliding gear would have to have three positions with the center neutral. Since you just told us there's only two positions I would make the assumption that you don't have the two speed option

Btown · Dec 4, 2022

The grinding issue is your clutch needs adjustment.

setxjeff · Dec 4, 2022

My International harvester 254 (25 hp) has a two speed Pto. You have to take a plate off at the Pto lever and flip it over so the pto lever will go the other way.

TractorTech · Dec 4, 2022

US 1920s did not have a two speed PTO. Those that have two speeds are 540 and 750 rpm. There is usually a lever on the side of the rear case that allows the sliding collar to shift from one to the other.
And, as Btown indicates, the clutch needs adjusting. Could be a double clutch, where the main transmission clutch is fine, but the PTO clutch needs adjusting via the rubber plug on the side of the clutch bell housing. Other posts explain procedure.

scootr · Dec 4, 2022

My now gone Terex 640 had the 2 speed PTO. It had a position lever marked 540 - N - 1080.
I used the 1080 for one mowing. It really made the BH sing but I worried the BH was not made for the high speed.

grcutter · Dec 5, 2022

Thanks everyone.
I'm now convinced that my PTO is single speed only.

I'll look up the procedure to adjust the PTO clutch through the hole with the rubber plug.
I'm concerned that it may be more than the clutch since there is a position of the PTO shaft with no grinding but all no spinning....
But I will try to remain optimistic.

TractorTech · Dec 5, 2022

grcutter said:
Thanks everyone.
I'm now convinced that my PTO is single speed only.

I'll look up the procedure to adjust the PTO clutch through the hole with the rubber plug.
I'm concerned that it may be more than the clutch since there is a position of the PTO shaft with no grinding but all no spinning....
But I will try to remain optimistic.

Just wondering. On the double clutch unit, when you depress the clutch half-way, you are disengaging the transmission clutch. When you depress the clutch all the way down, you are releasing the PTO clutch. Is that what you mean when you say, "there is a position of the PTO shaft with no grinding but all no spinning...."?

grcutter · Dec 5, 2022

TractorTech said:
Just wondering. On the double clutch unit, when you depress the clutch half-way, you are disengaging the transmission clutch. When you depress the clutch all the way down, you are releasing the PTO clutch. Is that what you mean when you say, "there is a position of the PTO shaft with no grinding but all no spinning...."?

My clutch appears to disconnect both the PTO and the main clutch at the same time with just about 25% of the pedal pushed in.

I realize that I may not have described the 'no grinding' situation very well so I will try again:
With the PTO lever engaged and the clutch fully out, I noticed that occasionally there is no PTO shaft grinding but also no PTO shaft rotation at the same time.
Under these conditions, I tried to rotate the PTO shaft back and forth a little bit by hand and found that there is a tiny range (maybe an angle of < 10 degrees) where it does not rotate even though it is engaged.
Beyond this small range, the shaft will 'catch' and start to rotate but with grinding.
The other thing that happens with the PTO grinding is that the PTO lever gets pushed back out of position and becomes disengaged all by itself.

I'm not sure what to think about the small range with no rotation.
I'm imagining a PTO shaft that is missing a few splines on a portion of the shaft but maybe there is some clutch related explanation for this.

What pushes the PTO lever back out? Is this also a bad clutch alignment symptom?

Tractor Tech · Dec 6, 2022

I still am not sure about the small erange of no movement you are talking about, but the lever popping out and the grinding makes some sense.
The detent spring on the PTO shift rail is not as strong or the gears that engage the PTO are really worn allowing it to slip out. This could also be why it grinds.
I don't remember, but I think the 1920 had a problem with the detent spring anyway, but could be thing of the 1910