open differential drive

Question? In an attempt to create front wheel assist, is it possible to drive the hubs of a 9" ford axle from the tractors axle creating a transfer case unit to drive the front end. This would mount under the tractor axle and likeley be chain driven, the axle would be cut to length for the proper geometry driveshaft to the front end Would the output shaft rpm on the 9" ford be equal from the open differential/open differential to the tractors rear drive axle. Simply if two axles were connected at the hubs would output/input speeds be equal in cornering

Possible yes will it work well maybe maybe not. Over the years I have seen some real neat stuff built by people that either had to much $$ or to much time and they come up with some odd stuff

Had a guy here that made a mechanical rear wheel drive for a JD 105 combine. This was over thirty years ago.

He took the axles off of a 4 x 4 pickup. He mounted the solid rear axle under the front of the combine and ran chains down to each end from the final drive shafts. This was how he got the power for the rear axle by back driving the truck rear end. then he ran a drive shaft to the back of the combine. Here he mounted the front steering axle of the the pickup. He then had a chain sprocket setup to drive the axle. He had to do this to get the ratios correct for the different tire sizes.

It worked. We had several muddy years there in the early 1980s. He was able to combine where he would not have without the back axle helping. The only bad thing was that he had to remove the drive chains to go down the road. I think they would turn too fast and get thrown off at road speeds. It might have been the ratio was off just a little and on the solid ground it broke the chains. I am not sure anymore. I always thought that it was real smart how he made it work. I wish I had some pictures.

It seemed like in years past you saw a lot of things that guys made like that. Many times it would be livestock equipment or buildings too. We seem to have lost that in the quest to larger farms.

It will take less time and money plus it will work better. Just to trade your existing 2WD for a 4 WD.

Thanks for the reply, the theory made sense in my head but so has some other things that well....And yes it would be cheaper and less work to trade but then I would still have all these axles and shafts lying around. Lockout hubs would solve the problem of road travel. This would only be used in the winter for plowing snow so it shouldn't be a torque issue only traction on ice. I can see building mounts where the whole thing can be unbolted from the Farmall M and the narrow front replaced, the drive sprokets removed from the tractor axle(which would mean pulling the tires off, bummer) and it would be original again,

My long time neighbor/farmer friend had a similar thing done with their JD 6620 combine. I assume, because I don't recall what it looked like before, that it did not have rear axle drive. His son said that they took the drive train from a 7000 series combine, and fit it up under there. I have greased this combine many times, it sure looked factory, but I wondered if there were any unique "snags" in the process. They also put new front tires on, oversize, the concern there was finding a weak spot say in the axles, in real deep sucking mud or if it got stuck so they operated it with that in mind, reason being for this modification was that like you mention, the harvest for so many years put them in the field with terrible conditions. I can attest to that by having to fix all the ruts where it was wet, but that 6620 would seem to get through most of it, 1st round in at my place though, there must have been a really saturated area, which does not occur much in this field, sunk in but good, 3150 pulled it out with it assisting itself too, without any trouble. I do have some photos of it combining oats, some small video from an old camera too, it sure looked like a beast that could muscle through some soft ground.

I have a retired neighbor who was one of those guys, would build trucks with multiple auxiliary transmissions and all sorts of ingenious, but creative mechanical wonders, very interesting and lots of fun pondering how he did things etc. Lost art today !

(quoted from post at 11:10:32 10/18/12) Thanks for the reply, the theory made sense in my head but so has some other things that well....And yes it would be cheaper and less work to trade but then I would still have all these axles and shafts lying around. Lockout hubs would solve the problem of road travel. This would only be used in the winter for plowing snow so it shouldn't be a torque issue only traction on ice. I can see building mounts where the whole thing can be unbolted from the Farmall M and the narrow front replaced, the drive sprokets removed from the tractor axle(which would mean pulling the tires off, bummer) and it would be original again,

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I LIKE the concept. Could get complicated to build, but it would be a neat project.

I know what you mean as for the build. I have a 1969 Chev 3/4 ton truck that I have wanted to cut the frame so as to make a straight frame then add a 2nd rear end and set it up with tandem drive in the rear and also add an aux transmission to it so it would have 16 forward gears and 4 reverse gears. Had a guy tell me how to do the tandem powered rear just the other day by taking the front pinion drive out of a rear end and installing it up side down on the back of one then a drive shaft to the rear rear end

Very cool idea, I have had a similar idea using 9" ford rearends, cutting off the cover and mount the second pinion carrier but got stumped when it came to supporting the second (driven) pinion shaft and how to set backlash, possibly a access cover on top. I grew up fixing my fords and spent a lot of time in junkyards cuz new parts were too pricey for me then, so I'm kind of a one flavor guy, does the GM axles overcome this somehow, a 6X6 would be bad A$$

Well the way I understand it is this. On the 3/4 ton rear ends of the Chev you have a bolt on pinion plat and a bolt on back cover that have the same bolt pattern. So you take the back cover off and then bolt on a front pinion type cover so you then have a drive out the back of the front rear end so you can then hook a drive shaft to the next rear end to drive that back rear end. My ides is to make a truck that looks like a mini semi so it would have 10 tires and stacks up and out behind the cab with a 5th wheel plate so as to pull a trailer that would look like a mini low boy and that is the reason for the 16 forward gears so you have a gear for every thing

That would definitely turn heads going down the road. When I was in the army we had 8x8 HEMTT rigs built by Oshkosh, the front two axles steered. I've always wanted to do a scaled down version of it using automotive components, but the engineering seemed daunting especially since I hadn't figured out the rear tandems, adding non driven axles would be like cheating so that is as far as it got. Thanks for the food for thought, I'm sure the wife will be thank you as well when I start dragging home old Chevrolet's.

That is one problem I do not have. My wife knew I was a mechanic before we got married and she also knew I was a pack rat type guy so she NEVER says a think because she knows all that would do was get it so she could not have things she wants. I have an old army mule in my shed right now that is owned by a friend and that friend has a army 6X6 that I drove home for him when he got it. I have around 30 tractors on the place. & or so big rigs as in 10 wheel trucks place about 10 or so old cars and trucks. I also have on the drafting table and idea of making a scale down model of a tank with a full set of working guns. Something like a 10 or 8 gauge shotgun for the big gun then an SKS etc for the small gun

Ever thought of hydraulic motors? The rice farmers around here have used "Mud hogs" on thier combines for years.Thy were nothing but hydraulic motors on the steering axles for coverting the combines to all wheel drives.

neighbor has a WD with home built front wheel drive. Looks like some sort of rear end out of a Power Wagon or something like that.