Governor End Play

[Sailor]

I ran across this measurement while I was reading about the governor, so I measured mine. The problem I am having is it isn't real clear were to make the measurement. I took the measurement between the M/G gear and the piece of metal that protrudes out from the governor's base. (see picture)

The shaft the gear is attached to has considerable end play, from .023 to .063, which I think is a not a good thing but when everything is bolted up I don't see how that shaft could travel any. End play measurement is within specs when the shaft/gear is pushed back into the base.

Also, is the Speed Adjusting Screw supposed to safety wired?

Thanks,
Larry

[Sailor]

I forgot to add, the specified clearance should be between .020 and .025. I hope with this additional information somebody can give me some guidance.

Thanks, Larry

[challenger]

You may be over spec. some, but I do not believe this shaft end play is a serious consideration. I suppose you could shim out the overage if you want, but you will have to drive the pin out to get the weight mechanism off the shaft before you can do so and otherwise pretty much disassemble the governor.

[Criswell]

Where you are taking the measurement for the end play is the correct location, between the gear and the governor base. If your 0.063" number is accurate, that is more than 1/32" in excess of the upper limit, that is a lot. With each governor that I have taken apart to rebuild (except for two) I have found the same thing in each one, a fiber thrust washer:



This washer would fit between the weight carrier and the governor base. This washer would prevent any direct metal to metal contact and also help to set the proper end play on the shaft. The only times that I have seen this part mentioned is when someone has talked about some type of a "broken gasket" that fell out of the governor during a rebuild/inspection. If this thrust washer is gone/missing/worn, the end play on the shaft would be significant.

The governor shaft assembly came with four different part numbers, 251456R91, 251456R93 (serial number 501 to 106701, through April 1950), 355303R91 (serial number 106702 to 164223, May 1950 through January 1953) and 357440R91 (serial number 164223 until the end of production). Each number listed would logically indicate a change in the design of the governor shaft assembly. Of the eight governors that I have taken apart, six had the washer and two did not (both without the washer falling within the early part number range). The governor shaft assembly included the governor shaft, drive gear, governor base, weight carrier and pin for the weight carrier, and came as an assembled unit.

This is a picture of an early governor which has the weight carrier that is made of two pieces that have been welded together and is held to the governor shaft by a 5/32” groove pin. The actual weight carrier is made from a stamped piece of material welded to the base. This is one of the two governors that did not have the fiber thrust washer and the weight carrier and governor base had eaten each other up.



There had been some talk in other posts about placing shims in to take-up the amount of end play in the shaft. In one governor rebuild that I had done, the thrust washer was cracked and would have surely broken if reinstalled and allowed to run. I had chosen to just replace the thrust washer. The washer was the same dimension as the fiber thrust washer used in an early (27-28) Ford Model A starter. Check to see if this fiber thrust washer is in place between the weight carrier and the governor base, this may be the point of your excessive end play.

[Sailor]

Where you are taking the measurement for the end play is the correct location, between the gear and the governor base. If your 0.063" number is accurate, that is more than 1/32" in excess of the upper limit, that is a lot.

The 0.063" is the spacing when I pull out on the gear/shaft. When the gear/shaft is pushed back into the governor base, the gap is 0.024", which falls within the correct range of 0.020 - 0.025".

Since the governor performed correctly when the tractor was running, I'm thinking that when the governor is bolted back in place, there will not be any in-out play with the shaft. Do you think that is possible?

The part number on the governor is 251446R1.

Edit: I found a "how to" by Gary Boutwell that he posted back in 2009. He showed how the entire shaft assembly comes out of the base (with a little assistance from a hammer). That explains the "slop" in the shaft.

Again, it proves that a little research goes a long way.

[Criswell]

But the end play on yours is 0.024" - 0.063", not the 0.020" - 0.025" that is quoted in the specifications manual. That is 0.039" of back and forth motion in excess of the 0.025" specification. I would definitely look to see if the fiber washer is present or missing. With the governor off, this is the time.

I forgot about your question about the safety wire: The braided wire would be sealed with a lead seal once the engine RPM was set at the factory (or dealer for service). Just a way to show that it was set and not tampered with. I had a picture of one of the lead seals with the IH logo, but I can't find the file it is in.

[Bob McCarty]

Criswell, I've only done a couple of governors and neither had the fiber washer. I just looked in several of the parts manuals (Rudi's manuals) and can't find the washer pictured or listed (unless I missed it). Can you refer me to where you found this washer?

Thanks, Bob

[Criswell]

The only places that I have found the washer in question is when rebuilding a governor or it being mentioned here on the forum (mostly in a "what is this" question). It has been mentioned in a couple of different posts about finding a broken gasket or washer inside of the governor when doing an inspection or rebuild. Below is a link questioning the same item:

viewtopic.php?f=1&t=70432&p=570132&hilit=governor+end+play+washer#p570132

As I had stated above, with the exception of the two "early" governors, all the others had the washer in them (with one being cracked/broken). I have two more governors to go through and I am certain that both of those will have the same washer as well. There is no mention of it in any of the parts lists that I can see either. With the "governor shaft and carrier" being sold as an complete assembly (251456R91, 251456R93, 355303R91 or 357440R91 depending on which parts catalog your are looking at) and not individual parts, I do not think it was a part that you could get.

Each of the washers that were taken out of the governors that I have had, all came in right around 0.032" (+/- 0.0005) in thickness. A lot of the threads that I have read about the governor and the end play issue have excessive end play in that 1/32" range, right at the thickness of the thrust washers. A fiber thrust washer won't last forever, but it will last a long time. It wouldn't take much for the pieces and parts of a broken one to work themselves down into the oil pan.

I would love to be able to find an image or part number for this, but until I do all I have is what I have seen and held in my hands. If anyone has an N.O.S. governor shaft and carrier assembly hanging around, let's see some photos.

[Bob McCarty]

Here's an excess end play fix from the Van Ostrum governor rebuild power point in Rudi's manuals:

It was suggested that a thrust washer might be used to make up endplay. Yup, that works - and here's how I did it. 1 - punch out the rollpin that holds the weight carrier to the shaft. It comes out easy, just line up the holes in the casting and use a long punch or round stock of the appropriate diameter to push the pin out the other side. 2 - put the assembly in the vice (or a similar wooden block setup) such that the casting rests on top of the jaws and the gear passes between the jaws), i.e., shaft pointing up. 3 - put a piece of wood on the shaft end and tap shaft out of the casting and weight carrier (again, comes out easy). You now have three separate pieces - the casting, weight carrier, and gear/shaft. 4 - with the gear/shaft and casting assembled, place the appropriate number of 5/8" ID/1" (minimum) OD shims or thrust washers over the shaft. I couldn't find a thrust washer thinner than 0.065, so I used round, brass, 0.005" thick shims from McMaster and Carr (about $5 for 10 shims) . You can get them in other thicknesses and materials if you choose. 5 - tap or press the weight carrier back on the shaft (it will go on easily). Be sure the carrier is facing in the right direction and take care to line up the weight carrier rollpin holes with the hole in the shaft. 6 - tap the rollpin through the carrier and shaft. The pin should go in easily. If not, the holes in the carrier and shaft are not properly aligned. Reposition and try again. Be prepared to reposition a few times, do not try to force the rollpin through the hole. The pin is hardened and will scar up the shaft. I used all ten shims and reduced the endplay from 0.063 to 0.013 - the high spec limit according to the IT manual but a little less than suggested by the BR repair manual - I thought this was an acceptable compromise. Result: After the rebuild, governor picks up fast under load with speed change immediate and incremental along the entire sector range.

Bob

[challenger]

Excess axial play on the shaft will have some effect on overall governor performance. However, if I have the helical gear design figured out correctly, the gear on the governor is going to be thrust back against the governor hub when the engine is working or running at steady throttle. The only time the thrust would reverse would be on abrupt deceleration. Thus, excess end play would cause some delay in responsiveness following rapid deceleration. That explains why IH thought the fiber washer was adequate since it only makes contact during deceleration. Regardless of this consideration, I would not opt for a fiber washer to eliminate excess end play but would use standard shim stock.

[Criswell]

Thus, excess end play would cause some delay in responsiveness following rapid deceleration. That explains why IH thought the fiber washer was adequate since it only makes contact during deceleration. Regardless of this consideration, I would not opt for a fiber washer to eliminate excess end play but would use standard shim stock.

I do not think that the presence of the thrust washer is in its place for the responsiveness of the governor rather it is
for the self-preservation and durability of the governor. As the engine RPM lowers whether this deceleration is caused by moving the throttle or the engine being under load, a combination of the changing engine RPM and the flyweights opening/closing causing the governor shaft to thrust forward or backward. With a lower engine RPM the governor shaft would be "back" (towards the mag/dist) and there would need to be a bearing surface between the weight carrier and the governor base, not just for end play but for wear prevention.

The purpose of the fiber thrust washer (phenolic thrust bearing) is two-fold: One being the taking up and setting of the proper end play and two, as a bearing surface between the stationary governor base and the constantly rotating weight carrier. At lower engine RPM when the contact is being made at this point a bearing of some sort is going to be needed to prevent wear and premature failure (of more than just the governors internal parts). I believe that installing steel shims between two ductile gray iron castings where one is rotating and the other is stationary is not a good thing. Direct metal-to-metal contact such as this (even with lubrication present) never ends well.

The fiber thrust washer is a tried and true method that has been used for a long time (transmissions, distributors, generators, axles, etc.). I do not believe that it was chosen because it was adequate, rather it was the right material for the job. It has excellent compressive strength, high durability, a very low coefficient of friction (even lower with lubrication) and is low cost.

Either way, if there is excessive end play in the governor, it needs to be addressed. The engineers from IH did not take the time and effort to put the specification down in at least three different manuals because they had to, it is important. However the individual undertaking the repair/rebuild of their governor chooses to correct the problem is their choice entirely, I chose to use a part made of the same material and size that was present in the governors that I had worked on, that is why I opt for the fiber thrust washer.

[DRaymond]

My Governor shaft end clearance is 0.042". the IH-8 International Harvester Shop Manual October 2012, p 43, Fig. IH391 states that the end play should be 0.004-0.013. The Cub and Cub Low-Boy Tractors Service Manual, GSS 1411 W/Revision 1 Feb 1976 says "Governor shaft end clearance is adjusted by placing 0.020 inch thickness of feeler gauge stock between drive gear and governor assembly. After gear is pressed in place, the end clearance should be within the range of 0.020 to 0.025 inch."

As a practical matter the gear is not going to be able to be re-positioned so a thrust washer will be needed to bring the shaft end clearance within a specified tolerance. So two questions:

1. What is the correct end play tolerance range specification? .004" - .013" or .020" - .025"?; and
2. What is the specification/nominclature/part number for the fiber thrust washer or material?

How about bronze bushing material?

Thank you for any help