John Deere H Governor

[Lieu]

I recently restore a 1940 John Deere H. Late last year, I had it running real good so I decided it was time to take it apart and paint it. Now that I have the nice paint job on it and it is reassembled, it seems the governor is not working properly. The throttle is really sensitive and the least movement allows the engine to accelerate rapidly.

I am not a trained mechanic, but I got to thinking today, why would it run so good before I painted it, and now it runs too fast and the throttle is too sensitive. I took all the parts I could off to paint. Part #AH617R - Arm that comes out of the top of the governor case; I failed to get it off for the final paint coat so I painted it attached. However, thinking back, when I tried to pull it off, the shaft came out of the case about 1" or so. I turned it slightly and it went back down in the governor case. Is it possible that I didn't get it turned to the right position? How would one determine this and how would I fix it without having to take my nicely painted hood off (if possible). One other thing I have noticed, the foot throttle worked fine before I tore it down to paint it, now it bottoms out before moving the governor arm far enough to open up the throttle. Is this further evidence the arm is in the wrong position?

I appreciate feedback, thank you.

 

[dan_41jdh]

Marty, your statement that “the shaft came out of the case about 1 inch or so” is disturbing. Something is not right about that. The shaft can be pulled up a little, perhaps ¼”, but it is prevented from raising too far because the two fingers of the H401R lever trap the governor shaft, thus preventing the shaft and lever from being pulled up very far. And that shaft and lever cannot be rotated out far enough for the fingers to escape from surrounding the governor shaft. So if you pulled it up that far, I wonder if one of the two mounting screws for the lever are missing, permitting it to hinge about the remaining screw and out of the way when you pulled it up that far…..And from your description, it doesn’t sound as if your governor is reacting to engine speed at all.

But first, do a preliminary check to make sure there’s no interference or rubbing of the throttle rod going to the carburetor. Move the throttle handle to approximately mid-range and move that AH617R arm back and forth and make sure there’s absolutely no hinderance to its movement (other than spring force from the B273R flat leaf spring). And that includes the possibility of paint gumming up and preventing free rotation of the governor lever shaft (H400R).

The problem with the foot throttle is another matter - do you have the correct spring(s) in the correct location? The foot throttle should have a direct effect on engine response except when the hand throttle is completely closed because then the foot throttle springs can't move the throttle mechanism at all.

Here are a couple of pictures for you to verify your hookup and linkage arrangement.

 

[Mike(NEOhio)]

Possible when you pushed it back down the fork was out of place and not contacting the thrust bearing. Or the thrust bearing got away from the flyweight levers. It's possible to get the whole governor and fanshaft out of an H without taking off the hood. If you can do that turn it over and look inside.

 

[Mike(NEOhio)]

dan_41, I'm wondering if it's possible he turned the lever shaft when he pulled the lever off. Can the fork disengage the shaft when it's turned away from the thrust bearing?

 

[dan_41jdh]

Don't think so. Tried doing that to an "H" in my shop with all the linkages disconnected, and I can't get it to swivel far enough for the fingers to disengage.

 

[MSD]

There should be a small groove for the locking bolt to set in when the shaft is turned to the proper position. Take the bolt out and see if you can see in the hole if there is a slot there. If not try moving the gov. lever and see if it turns on the shaft so you can line it up. Might be why the foot throttle doesn't work also. If your not in the slot, then the fork is turned and could be missing the gov shaft which allows you to pull it up.

 

[Lieu]

Dan, It may not have come out an an inch; that happened last NOV, so memory may not be that good. You typed an L for how far it should come out. What do you mean by that? I am not sure I want to take the hood off to fix it. I'll have to think about that. It scrapes the paint off the steering wheel shaft whenever you have to take it off too, and as you know, that has to come off before the hood. They didn't design some of these things very well for show tractors!

 

[Mike M]

Good advice below about the gov. lever. In addition to that make sure there is nothing binding up the linkage. At the carb. end if you put a cotter pin in the bottom it is hard to get them NOT to bind. I use a smaller pin than the hole size.. Had a guy with a late B that would not run right after it was painted and turned out they left the rear fuel take rubber mounts out and the linkage was rubbing and binding up.

 

[dan_41jdh]

The value I typed was one-quarter of an inch, but some browsers will interpret and display a fraction differently. I then measured the movement on two “H” tractors, and both exhibited less than one-eighth inch of vertical movement. How far does yours move now?

MSD posted about the possibility that the AH617R arm might not be registered correctly to the shaft if the 3/8” setscrew is not piloted into the countersink on the shaft. In other words, could the arm be “out of time” with respect to the shaft? I had discounted that possibility at first since you stated you weren’t able to remove the arm, and I assumed that it was rusted solid onto the shaft and hadn’t been rotated and was still registered correctly to the shaft. That's definitely worth checking as it will drastically affect governor action.

Before proceeding with removing the governor, I’d suggest first testing the governor by removing the throttle rod from the AH617R arm. Enlist a competent helper to operate the carburetor throttle by hand at the carburetor to control engine speed, then start the engine. Position the hand throttle at about the midpoint of travel in order to apply some force to the flat spring and check if there is governor action. By holding the AH617R arm, you should be able to feel the governor exert changes of force as your helper speeds up and slows down the engine (more force moving it forward at high speed, less force at low speed). If you can’t detect smooth changes of force proportional to engine speed, you’ve got a governor problem and you’ll have to remove it for repair….

 

[dan_41jdh]

Incidentally, the I&T Shop Service Manual indicates the hood can remain in place when removing the governor and fan shaft assembly on an "H". I've never tried that, but it appears feasible. The Manual says to remove the starter and generator (if so equipped), the exhaust pipe, the breather pipe, the fuel filter bowl, and the magneto. Then unbolt the governor and remove it. That's a little oversimplified, but it does appear that it would be possible. Obviously, the throttle rod to the carburetor must be removed, and it appears the oil bath breather and the inlet to the carburetor should be removed, and probably the carburetor, also. Then the front fan bearing support can be unbolted, and with careful maneuvering, you should be able to swing the governor out the left side and move the assembly out. Probably less traumatic than tearing the hood off (and steering shaft and grills)....

 

[MSD]

Before taking the gov. off completely, take the cover off and look in there and see what is not right. You can remove the gov. itself without taking the whole case off also. We do it all the time.

 

[dan_41jdh]

Good point - you can remove the LH governor bearing housing and peek through the slots in the governor drive gear to get an idea if everything is in place and intact. However, have you pulled the governor assembly out of the case that way on an "H" which is arranged a little differently than an A, B, or G? I'm pretty sure you have to remove that forked lever first and there's good risk of dropping those little attaching screws into the crankcase, not to mention trying to realign the the forked lever and replace the screws during reassembly.

 

[Lieu]

Dan, I had some time to work on it again today. I got the governor arm off (I had had it off once to clean it but couldn't get it off before final paint) and made sure the slot lined up like one guy suggested. Most of my problem I discovered, was I had the throttle lever adjusted too long so it wouldn't let the AH617R arm go all the way back to neutral (toward radiator). I checked to make sure the linkage wasn't binding.

All of a sudden, it has gotten hard to start, sometimes 5-10 pulls and before it would start on 1-3. Not sure if these problems are connected.

After starting, I had a lot more range in the throttle, the governor wasn't causing it to run away. Here are some tendencies that I would like to try and work on if you have any advice:
1. When I decelerate from full throttle, it backfires.
2. Full throttle in shop, the governor shaft moves back and forth a bit causing the engine to speed up then slow down slightly.
3. Took it out for a drive, going up a grade it seemed to run pretty good at various throttle settings.
4. Going downhill, the governor was causing it to speed up and slow down a bit.

Any further advice?

P.S. The governor arm, AH617R has about 5/8 of upward slack in it.

 

[dan_41jdh]

Marty, I'm concerned about your statement of "The governor arm, AH617R has about 5/8 of upward slack in it." There is no way there should be so much vertical movement of that arm, and I'm also concerned about "Full throttle in shop, the governor shaft moves back and forth a bit causing the engine to speed up then slow down slightly." There shouldn't be any perceptible "rattle" or back and forth movement of that governor shaft - it should fit snugly in the bushed hole in the governor case. However, some "hunting" of engine speed might also be caused by improper carburetion settings. Same thing with speed variations going downhill.

You can determine if it's the governor or the carburetor by holding the carburetor throttle rod steady (preventing governor control) to see if the engine speed remains steady - if not, it's the carb. If you must manually move the carburetor throttle rod to maintain steady engine speed, it would appear the governor is doing its job.


Back to the vertical movement - the pictures show the H401R lever and the governor arrangement of an old set I dug out. You'll notice the throat opening of the H401R is approx. 1.10", and the OD of the H390R sleeve that it surrounds is approx.0.865". The difference leaves a maximum vertical movement of the H401R lever (and thus the AH617R arm) is only 0.135", just about the 1/8" I mentioned earlier. If you are getting 5/8" vertical movement, you have a serious problem with your governor. Please verify your measurement.

I am not sure what causes backfiring through the exhaust during deceleration - some people say it is because of a very lean mixture that won't ignite in the cylinder, but will ignite in the exhaust when there is little compression. Others say it is caused by a rich mixture. Not sure if anyone knows for certain.

 

[MSD]

What you need to do is first loosen the jamb nut on the shaft that holds the forks. Then get it loose so you can turn the throttle linkage on that shaft. Once you can do that, watch the forks in the case so that when you turn the shaft, they go all the way to the side of the case. This will allow room to pull the gov. out of the case. You need to take the mag off also but you can leave the fan shaft alone. Turn the governor so the weights are in the up and down position and it should come right out with a little wiggling of it. No need to remove the screws or the fork to get it out.

 

[dan_41jdh]

MSD, you're probably referring to either an "A", "B", or "G" with governor arrangements similar to the illustration. But this post is about an "H", and as you can see in the photo of an "H" governor, the weights are attached to the governor driven gear whereas on the other models, the weights are attached to the fan drive gear. I tried getting the governor out as you described and it just can't be done. There simply isn't enough room for the forks to swing out of the way. The fan drive gear hits the back of the forks, and the fork tips are hard up against the thrust bearing - and that's as far as the governor will come.....

 

[Lieu]

Hello Dan.

Last night, I would have given that H to the first guy who came along! LOL

This morning, I did the following steps:
1. Checked all the throttle and governor linkage, and carefully made sure it was set to an email with pictures you sent me last winter. I made a few changes as result.
2. Someone suggested where the throttle rod connects to the carb butterfly, use a smaller cotter pin. Even though it didn't look like it was dragging, I did that and I changed the direction I installed it. Linkage seemed to work a lot better.
3. Lastly, I reset the carb load and idle screws to Browning's book for initial starting.

Result, it started on the 3rd pull, and it ran the best I've had it running. No pulsing, I had full throttle range, and good power.

I will try again tomorrow to see if I can build on this success with consecutive days.

Thanks everyone who replied and helped.

 

[dan_41jdh]

Good to hear. Any linkage binding/interference/rubbing will fight the governor and cause all sorts of trouble. Glad you got it functioning.