Belt-Driven Governor

[ColoradoWDX]

I can't seem to identify the correct model number for the Pierce version of governor that replaced King-Seeley's original. Have read Clint's web pages and every other source I could find. Will one of the late production universal governors (Pierce GC979R5) work with the correct adaptation? I do have repro arms and pulley. Are there any sources for governor mounting bracket as well as in-cab governor control assembly? Any guidance would be greatly appreciated!

[Gordon Maney]

Clint, do you have an opinion here?

[ColoradoWDX]

Can anyone help? I'm open to guesses and/ or opinions, anything! Thanks!

[CSCameron]

Rather than wait for a response here, why not directly email Clint Dixon? I'm sure he will be able to answer your question.

[Gordon Maney]

I am going to send Clint a note. He must be asleep.

[Clint Dixon]

I can't seem to identify the correct model number for the Pierce version of governor that replaced King-Seeley's original. Have read Clint's web pages and every other source I could find. Will one of the late production universal governors (Pierce GC979R5) work with the correct adaptation? I do have repro arms and pulley. Are there any sources for governor mounting bracket as well as in-cab governor control assembly? Any guidance would be greatly appreciated!

I would not really say that a Pierce governor replaced the King-Seeley original. The first couple Power-Wagon parts manuals start out by advising that governor orders be sent directly to King-Seeley. The next few manuals direct orders to Pierce. Then, later manuals changed back to directing orders to King-Seeley.

I believe King-Seeley was the original manufacturer even though during that time period Pierce held more patents on governor design. In fact, I have found Pierce patents that closely resemble the King-Seeley used on the Power-Wagon, but no King-Seeley patents that resemble the final product.

In any case, there may have been a time period when King-Seeley could not keep up with the demand and Pierce took over production, later to be returned to King-Seeley.

I have examined both King-Seeley and Pierce original equipment Power-Wagon governors and there are no differences between the two other than the the name on the label stating the company of manufacture. Both had exactly the same model number and part number. The model number was 26510-414 (sometimes without the dash). The Chrysler part number was 1189 749. You will not find this number listed in any of the Power-Wagon specific parts manuals as it was the number for the complete assembly. The parts manuals show only the numbers for the individual parts, attaching bracket, throttle control, etc. This assembly part number only appears on the governor itself. It had to exist somewhere on paper - maybe only at King-Seeley/Pierce or on a BOM within the purchasing department at Chrysler. Somehow, King-Seeley/Pierce knew when PO's came in for Power-Wagon governors they were to invoice for part number 1189 749.

As far as a later Pierce that could replace the original model 26510-414, Dave Butler found around 20 or so NOS pierce governors that were "close" but still required a lot of work to adapt for use on a Power-Wagon. I do not remember the model number on those but I may know a person that bought one of the reproduction kits that Vintage authorized. I will see if I can get that information.

At one time, I had collected about two dozen different governors from different manufactures including Pierce and King-Seeley. These ranged in years that appeared to be from the 1940's up into the 1970's, with the later ones having aluminum housings instead of cast iron. I never found a better governor to use to attempt a reproduction than the ones Dave Butler had found. The problem is in the geometry and dimensional relationship between the axis of the rockshaft and the axis of the pivot for the arm that connects back to the control in the cab. These locations of these two axis are determined by the casting of the housings. The distances in both X and Y directions of them from each other is very important. The original Power-Wagon control arms were designed to work in conjunction with this set dimension. Any variation from that renders the adaption of original (or reproduction) control arms to a different spacing useless.

The combined geometry of the internals of the governor, the external control arms, and all the linkages is very important. When setting up the governor, there are several distances and spring tensions that can be adjusted. Each one is critical to governor operation and each one results in major changes with only minute adjustments. For instance, it is a very time consuming task to set an original Power-Wagon governor, with all original external parts, correctly back to factory specs if someone has tampered with it, or even if it has been removed from one truck and installed upon another. Even when removing and reinstalling the drive belt, some settings need to be readjusted.

I am not saying a newer Pierce can not be found that would work. I have just not found one yet. I will see if I can get a model number from one of the NOS ones that Dave found several years ago. Feel free to email me through this forum.

[ColoradoWDX]

Clint,

Many thanks for your response as well as the education--both are greatly appreciated! I would not be asking had I not acquired a complete (minus the correct pulley block) rear PTO system this spring. As luck would have it, I acquired a second just a month later. At that point I'd been searching for rear PTO parts off and on for the 18 years I've owned the WDX. Imagine that! In any case, my search for a suitable governor may be even more challenging.

I'll stand by for any part number update you can forward. What about the mounting plate and in-cab governor control? Waiting to hear back from someone selling a repro setup, but looking for a second setup as well. Worse case is I will attempt making my own. One final question--do you have the correct shaft spacing dimensions for the original governor? Thanks for your help!

Best regards...

Dave

[Clint Dixon]

Clint,

Many thanks for your response as well as the education--both are greatly appreciated! I would not be asking had I not acquired a complete (minus the correct pulley block) rear PTO system this spring. As luck would have it, I acquired a second just a month later. At that point I'd been searching for rear PTO parts off and on for the 18 years I've owned the WDX. Imagine that! In any case, my search for a suitable governor may be even more challenging.

I'll stand by for any part number update you can forward. What about the mounting plate and in-cab governor control? Waiting to hear back from someone selling a repro setup, but looking for a second setup as well. Worse case is I will attempt making my own. One final question--do you have the correct shaft spacing dimensions for the original governor? Thanks for your help!

Best regards...

Dave

With the truck sitting unloaded on level concrete, and the governor mounted and set in working condition, the control arm pivot stud is located 1.375 inches ahead of, and 1.000 inches lower than, the rockshaft which exits out through the governor housing. The rockshaft rotation is controlled by the internal fly-weights and the arm that pins to the rockshaft in turn controls the throttle dog lever through a telescopic linkage. The control arm pivot stud is what the long control arm levers about. It is connected by linkage to the under dash throttle control.

These dimensions were taken using a small square and a line level to determine horizontal and vertical. Both dimensions are from axis to axis to the best that I can determine by eye. A straight line drawn between the axis is approximately 1-11/16 inch.

The attached image shows two of the old VPW reproduction governors. The one in my left hand is a NOS Pierce as found. The one in my right hand is after the work was completed to adapt the governor for Power-Wagon use. The number G3170 shown on the cast housing may be of more help than a model number. All housings cast with this number should have the same shaft-to-stud spacing. I believe this was slightly wider than an original Power-Wagon King-Seeley or Pierce, but still much closer than all of the governors I have had here. Those that I have left measure about 2-1/4 inches and higher with the newer ones measuring the greatest. The major rework involved everything internal and external being swapped from left hand to right hand with drilling and tapping of blank bosses on the housing.

Different model numbers using this same casting will have various combinations of other differences, including overall housing extension length (out towards the pulley), mounting bolt adjustment slot pattern in the housing extension (this is where the entire governor mounts to the bracket from the cylinder head of the engine), pulley type-size-shape, the pulley location in respect to the governor housing extension mounting surface (shaft length), etc. The extension housing on the governors is not exactly the same shape or length as an original King-Seeley or Pierce. The pulleys on the repo governors would not line up correctly with drive pulley on the trucks water pump when using an original mounting bracket. A new bracket had to be designed that was about 1/2 inch different than the original. I can not remember if the governor had to be moved forward or back to line up, but the new bracket had to be held against an original one to tell the difference. Making an exact reproduction clutch pulley for the repro governors would have made the misalignment even more severe - not to mention that an original would have had to have been destroyed in order to take it apart to reverse engineer the internal features of the dog clutch.

I am not aware of any other application that used the same in-cab control, the governor-to-engine mounting bracket, or carburetor dog levers, but all of these can and have previously been made.

I will try to get that model number for you. In the meantime, sharpen up your pencil, dust off your slide rule, and freshen up on your Trigonometry skills.

[Gordon Maney]

Good job, Clint!

[ColoradoWDX]

Again, thank you for your time! Your explanation makes perfect sense, especially where machining is involved. Last time I used a slide rule was my first year in the College of Engineering at Ohio State many years ago!

I checked the specs for the Pierce universal belt-driven governor. The drawings had enough detail to afford interpolation of the measurements you highlighted. Distance centerline-to-centerline from rocker shaft to pivot shaft is approximately 1-7/8 inches. As for the distance vertically centerline-to-centerline, it comes in at 5/8 inches; considerably less than your governor. Not sure this is as critical as the angular displacement of the rocker shaft which is limited to 15 degrees of angular displacement. Any deficit here would involve change the length of control rods.

One good feature of this model is its application flexibility. The mounting flange has four different positions, the pivot shaft can be mounted on either side, and the rocker shaft is exposed on bothe sides. Distance from the mounting flange to the end of the pulley shaft is 2.86 inches. Shaft diameter is 0.6245 inches. It may not be a good match for a purist, but I would think it might be a player in terms of functionality.

I have a 5'x10' plasma CNC system that can handle the in-cab governor control as well as the mounting bracket. Initial problem is I don't have either part to reverse engineer. Any idea where I can find either drawings or dimensions? As for the dog clutch, it would not make sense to destroy one just to reverse engineer. I have a few ideas regarding a simple disconnect mechanism and will engage the pulley dilemma after I can get past the basics you have identified.

Best regards...

Dave