John Deere 40U - Governor linkage issues

[Glen D Anderson]

Good day!

In the process of overhauling our 40U and going through the governor / carburetor linkage adjustment I've run into a bit of a snag. When trying to adjust the carburetor to governor rod length as per the SM I find that the rod appears to be too short.

With the throttle lever in the WOT position, adjust the rod until it just slips into the carburetor shaft arm which is to be held forward(WOT position) and then thread the rod into the ball joint 2 additional turns.

Well, as per the attached picture, the rod on this machine isn't even engaged into the ball joint(unless I pull the governor arm rearward against spring pressure). Looking closely at the end of the rod(90 bend) that connects to the carburetor arm it appears to have been repaired / reworked so I was wondering if it somehow got shortened in the process? I never paid attention to whether there was tension on this linkage when I took it apart well over a year ago so I just don't know...LOL

Also, you may note the new ball joint in the picture. It is dimensionally the same as the old one and I did notice it was only threaded onto the shaft 2 - 3 turns leading me to further question the rod length?

Thoughts? Anyone have a spare rod laying around they could measure? LOL

TIA

 

[Hotflashjr]

I can measure the one on my 40U tonight when I get home for you.

It does seem like the rod is too short though.

 

[jCarroll]

I measured two of my model 40s....... both are 9.875


or nine and seven eights inches.

 

[Glen D Anderson]

Thanks gents!

Once I get a chance to look at this project again I'll report back.

Got to thinking that cumulative wear in the governor could also cause this problem. The governor arm could potentially sit further ahead. I didn't notice any abnormal wear in the governor parts when I had it apart but I never actually measured anything.

 

[M-MAN]

Did you set the governor rod 1st?

 

[Glen D Anderson]

I wasn't sure where you took your measurements but the rod length on our tractor, excluding the bend is approximately 9".

With the ball joint installed with a reasonable amount of engagement on the threads the measurement is almost exactly 9.875" center to center on the pivot points. Going by that I'm assuming my rod is factory length.......

(quoted from post at 07:40:23 12/09/22) I measured two of my model 40s....... both are 9.875


or nine and seven eights inches.

 

[Glen D Anderson]

I attempted to set the governor to carb rod 1st as per the SM.

I ended up replacing the ball and socket joint with a heim style joint that had a longer set of threads. This allowed for the "2 turns shorter" adjustment on the governor to carb rod. I then adjusted the throttle to governor rod to the recommended "2 turns longer".

I haven't run the engine yet but manually cycling shows that I'm getting idle and WOT positions at the carb in respect to the throttle lever control.

(quoted from post at 19:12:14 12/09/22) Did you set the governor rod 1st?