Building a tractor from scratch---opinions/suggestions welcome

[novaman68]

I am kicking around building my own little tractor. I have a Allis Chalmers WD45 with a loader, so this machine doesn't have to have a loader. I want something that will be smaller, lighter and more maneuverable than my WD45. Here is a list of the parts I have to work with.

Wisconsin VH4D 4 cylinder engine (30hp/65ft-lbs torque)
3 speed transmission w/clutch (currently attached to VH4D)
4 speed truck transmission (SM420 or Ford truck trans)
Dana 70 full floater w/4.10 gears
IH combine steer axle/steering valve
All the hydraulics

I'm still on the fence if I want it to be front or rear steer. It will have hydraulic steering, a 3pt, high flow hydraulics, both the 3 & 4 speed transmissions will be run inline...3spd first since it's the weaker of the pair. I have a (rather poor) drawing attached to kind of give an idea of what I have in mind on the power train setup. I'm not sure I like the jack shafts, but it's the best way I could think of to keep the overall length of the machine down. I am open to suggestions---I'm still in the parts gathering stage at this point, now is the time to change plans if need be.

here is a link to the motor info Wisconsin Motors | VH4D Engine Description & Specs

 

[GPintheMitten]

I don't know much about this type of thing. But I would try to make the drive line as straight as possible. Aren't some rear ends built with the differential offset to one side? If so, that might help you keep the drive line straight and still make room for the engine on the longer side.

Regardless, I'll tune in to your project. Good Luck.

Afterthought: How about a front axle from a 4wd truck. I have read about people shortening the width of axles but I don't know how hard that is to do.

 

[novaman68]

I thought about a 4wd truck axle, but I didn't want to over complicate this machine trying to make it 4x4...since this is my first build of this type. As for the driveshaft angle, like I said that is a rather poor drawing. I drew that up to show the basic layout of the drive line. The engine will be as centered as possible, & with jack shafts I can tuck the 2nd trans somewhat underneath the 1st. I understand about driveshaft angles, so in reality everything will be tucked in as tight as possible, with the correct driveline angles. I forgot to say in my original post that I'm going to use pillow blocks to support the jack shafts & the input shaft on the 2nd trans. I'm also thinking about running 37" hummer tires since they are cheap to find around here used.

 

[GPintheMitten]

Sounds good.

 

[284 International]

You could also replace each chain drive with a transfer case from some 4x4 vehicle, and get an additional set of ranges/speeds, and avoid the trouble of running so much torque through a single chain drive. Mixing an approximately 2:1 reduction transfer case with a 2.5-3:1 case would let you split gears even more, and perhaps be more compact than the chains. They are already set up with front and rear output/input for your PTO shaft, too, and you could even set up a front and rear PTO drive. You can "clock" some of the more popular transfer cases and orient them in a rotated fashion if you need to compress things.

 

[FDuce]

http://www.tractorbynet.com/forums/build-yourself/93861-diy-home-built-compact-tractor.html

I don't know if it ever got finished but this was shaping up to be one of the best I've seen.

 

[Iplayfarmer]

Consider this... Most tractors have a solid frame with no suspension (other than the movement in the front axle). That being the case, you don't need a u-joint or a long driveshaft to distribute the flexing of a suspended frame. If your drawing is close to scale it looks like you have room to move at least one of your transmissions back a bit and get rid of the jack shafts.

I'm excited to see this build progress.

 

[cowski]

if you use tractor tires gearing will be too high .

 

[novaman68]

I like the transfer case idea...I'd imagine a divorced T-case would make things easiest. As for the drawing....its not to scale, like I said its a poor drawing I whipped up in a few minutes. I don't understand why it it would be geared too high with tractor tires considering I'm running 2 transmissions in tandem. This is just a rough guess, but with both transmissions in low, & 4.10 gears...I'm thinking I will be around 11:1. I'm probably going to run 37" hummer tires anyway.

 

[roygage]

I am kicking around building my own little tractor. I have a Allis Chalmers WD45 with a loader, so this machine doesn't have to have a loader. I want something that will be smaller, lighter and more maneuverable than my WD45. Here is a list of the parts I have to work with.

Wisconsin VH4D 4 cylinder engine (30hp/65ft-lbs torque)
3 speed transmission w/clutch (currently attached to VH4D)
4 speed truck transmission (SM420 or Ford truck trans)
Dana 70 full floater w/4.10 gears
IH combine steer axle/steering valve
All the hydraulics

I'm still on the fence if I want it to be front or rear steer. It will have hydraulic steering, a 3pt, high flow hydraulics, both the 3 & 4 speed transmissions will be run inline...3spd first since it's the weaker of the pair. I have a (rather poor) drawing attached to kind of give an idea of what I have in mind on the power train setup. I'm not sure I like the jack shafts, but it's the best way I could think of to keep the overall length of the machine down. I am open to suggestions---I'm still in the parts gathering stage at this point, now is the time to change plans if need be.

here is a link to the motor info Wisconsin Motors | VH4D Engine Description & Specs

Have been running my home-built for about 15 years. Daydreamed about it for fifteen years prior to building.

I always found using two transmissions got too long, I do see your doubling back with yours to shorten it up.

I used a Nissan Sentra front wheel drive engine and five speed transaxle. Turned the engine ninety degrees so the frt. of crankshaft faced forward. tore apart the transaxle and welded spiders in the differential. Welding them allowed me to use only one of the driveshafts, the one which "now" points forward.

Mounted a transfer case from a 84 Nissan pickup, this is what they call a divorced transfer case, forward of the engine and ran the driveshaft into it. hooked another drive shaft out of the transfer case and ran it back directly under the engine to a nine inch ford differential.

Made some adapters out of1/2 steel plate which allowed me to bolt up semi truck alum rims. By turning the rims so they are reversed as on the frt. axle of a semi I never had to narrow the differential.

Used a PS steering gear out of a front wheel drive car.

Has been a very reliable unit, Five speed, hi lo range power steering, geared very nice. 14 inch tires up frt.