Willys Truck Front PTO Winch Drive Line

[dgoodenow]

I'm working on a Willys truck with the Koenig Model 40 twin stick PTO, Koenig Model 100 winch, and the rear PTO drum belt drive. I have all the parts except for the front PTO drive line, that which connects the PTO to the winch. I think I will need to make one up and I was wonder if it is a two piece drive line like the rear is, or is it only a single piece? Thanks for any help.

[bmorgil]

dg, I am pretty sure they used the "Detroit Style" plunging joint. It is similar to the Bendix style that was used in the early front axles. The same type used in the Willys truck main driveshaft. LarrBeard has great experience with those types of driveshafts. In any event the best bet is to use a standard "Slip Between Center" 2 piece driveshaft and u-joints. Use at least 2 1/2 inch diameter tubing.

[LarrBeard]

What is the basic year of the truck - and post us some pictures. It sounds like a pretty nicely tricked out Jeep.

[dgoodenow]

Guys: The truck is a work in progress and I am still collecting parts, but I did find a picture showing a Willys truck with both the front and rear pto and drives. The picture looks to me to show a 1 piece front driveline? Thanks.

10090

[bmorgil]

That is correct dg, the Detroit Plunging Style drivehaft is one piece. You will need to make an adapter to a standard Spicer style flange, and use a standard slip between center driveshaft with flanges on each end.

[dgoodenow]

Thanks what I was thinking. The Koenig Model 40 front output shaft is 1 inch with a 1/4 inch keyway, and the Koenig Model 100 winch output shaft is 7/8 inch with a 3/16 inch keyway. I can find both size yokes, and than two receiving yokes one with a slip yoke and the other one not, with the same size shaft opening to connect the front part and the rear part together. Does this sound right? Thanks.

[bmorgil]

I think you have it dg. You need to hook up to the input and output shafts and then mate those to a slip yoke/tube shaft on one end and a tube yoke on the other end. There are a few P.T.O. shops that are around that could probably fix you right up. The most important thing is the diameter of the driveshaft. As I stated before and cannot state it enough, do not use small diameter tubing. You will need at least 2 1/2" diameter tubing depending on the shaft RPM and length of the shaft. Use too small of a diameter tubing and the shaft will fly out at high RPM do to a phenomenon known as "Critical Speed".

[LarrBeard]

"shaft will fly out at high RPM do to a phenomenon known as "Critical Speed".

And I suspect that phenomenon is something to avoid. Tell us more about that Doc Dana.

[dgoodenow]

I thought the rear pto shafts were tube, see attached, but the front pto shafts were solid rod, especially the end with the splines that fit into the slip yoke?

10092

[bmorgil]

The shafts you have pictured are not solid. The shafts change length by "Plunging" the joint itself which is on rollers that move in and out in the large outer plunging case or "Bell".
10093

There is some solid, very short shafting involved at the ends. The bulk of the shaft is tubing however.

"Critical Speed" is a phenomenon that occurs when a driveshaft RPM exceeds the capability of the driveshaft to stay in a straight line. As RPM increases the driveshaft begins to deflect in the center. Picture a Jump rope. The faster you spin it the more it bends in the middle. The heavier it is the quicker it bends in the middle and so on. With a driveshaft there are a few factors involved but for this conversation and the safety of all, driveshaft tube diameter and thickness vs length and RPM are some of the things critical to the equation. In general, the longer a driveshaft is the more diameter that is required in the tubing. Heavy or thicker isn't better and will lower the critical speed because of weight and that "Equation" we spoke of. Solid shafting has a very low critical speed and must be kept to minimum lengths. Arbitrarily selecting driveshaft material, size and diameter has and will kill someone.

Contact Fort Wayne Clutch & Driveline https://fortwayneclutch.com/product/1952-plymouth-cambridge-rear-driveshaft-replaces-detroit-ballnpin-roller-pot-style-sku-1310_plycam/ for a conversion shaft. They are in LarrBeard's neck of the woods. I think Larry may have already spoken to them about converting the plunging shaft on his Willys.

[dgoodenow]

I am only wanting to do this right, but the pictures shown in the last response are for axle drivelines and rear pto drivelines. My picture was for the two part rear pto driveline for the truck. I am looking for a PTO driveline that will operate the front winch to a Willys truck. The attached photos show what I'm looking for. Thanks.

10132

10131

10133

[bmorgil]

The first shafts you have pictured were also the type used on the Willys front and rear for some dealer and factory installed PTO's. The application changes the type of shafts required when equipment was installed. If the shaft is used to drive high power high RPM, or high torque low RPM or both, and the total length, that determines how the shaft is made. You need to apply your specific application to the specification capabilities of the components you are going to use.

The shaft you have pictured here is a solid P.T.O. shaft that can only be used in a low RPM situation. It appears to have standard Spicer solid shafting PTO driveshaft components. I do not know what MAX RPM your winch will operate at, but the shaft needs to be fabricated accordingly. If that is the original driveshaft, as long as it is correct for the application you are putting it in (Max HP and Speed required) it will be fine. Just remember if you are changing speeds and power, the driveshaft may need to be re-designed.

Your very best bet here is to run your application (Speeds, Ratios and Horsepower) past a shop that specializes in Power Take Off's like Fort Wayne Clutch & Driveline. They will fabricate a shaft that will keep everything running smoothly.

[dgoodenow]

Thanks, this makes sense. The pictures are not mine, I do not have the front pto drive shaft. I am looing for examples of what the front pto drive shaft was like originally to connect to the winch, in hopes of finding one or making one similar. My desire is to outfit the Willys truck with the rear pto belt drive pulley, and the front pto winch. I will probably never use either for any real application, it's for display purpose only. If the winch is to be used for some practical purpose at some time I expect it would be used at engine idle or low rpm and in first gear only.

[gmwillys]

The folks over at FarmJeep have compiled some info sources that may help you in getting to the bottom of what drive shaft you need;

https://www.farmjeep.com/farm-jeep-parts/implements/pto/

http://48cj2a.com/PTOs.htm

http://www.ewillys.com/2010/10/05/pto-tc-tranny-winch-sun-valley-ca-750/

http://www.ewillys.com/2010/04/19/ramsey-pto-winch-boulder-co-300/

http://www.ewillys.com/2010/01/10/a-pto-transfer-cases-colorado-springs-co/

Depending on who manufactured the winch, determines what style of drive shaft was used.

[dgoodenow]

Thanks. There appears to be a lot of information for the CJ's, but very little for the trucks. I know the PTO for the CJ's is different than the one for the trucks, I guess the angle of the drive shaft and the clearance is different.

[dgoodenow]

I think I finally have a picture of what I need, see attached. Thanks to all for your help.

10139

[dgoodenow]

After three months of searching, I now have all the parts to outfit my Willys truck with both the front PTO winch and the rear PTO belt drive, see attached. Thanks to Dr. Matt in MN for the Koenig Model 100 winch and the rear two piece drive shaft, Jeff in OR for the front PTO drive shaft, Mike in CA for the Koenig twin stick Model 40 PTO, Ted in CT for the rear PTO gear box, and Matt in PA for the belt drive pulley.

10246