log trailer with pto powered drive axle

[DMAK]

Hello all,

I am considering starting a new project, and was hoping to gather some ideas from you guys.  

I have access to some nice timber near my home and have been using my 26hp kubota with a log arch to get it home to my mill.  This setup works fine, but it is very slow.  On the way home I have to go up a short but steep pitch, which effectively limits the weight I can pull under the arch to one 12 foot log up to about 24 inches in diameter.  Even with loaded tires and wheel weights and 4wd I spin out on the steep pitch with some of the butt logs.  As I keep cutting more trees, I keep having to travel further from home. I am trying to come up with a cost effective solution that will speed up production. So far I have come up with the following idea:

Obtain or build a trailer built out of the back half of a 3/4 or 1 ton pickup-the type where you just remove the cab, bend the front frame rails together in and weld a hitch on.  Remove the bed and build some log bunks.  Devise a way to couple the PTO from the tractor to the differential under the trailer.  This would allow me to hopefully haul multiple logs at a time, and having a drive axle under the trailer would help me get up the steep pitch.  According to some online calculators, I would need about a 2:1 reduction in the 540 rpm PTO speed to make the wheels on the trailer go 3-4 mph.  The tractor is hydrostatic, so I can match the tractor speed to the trailer speed within reason.  That is with 4.10 gears in the differential and small diameter tires. My theoretical solution to that would be to utilize a divorced transfer case and keep it in low range.  It might also be possible to use a manual transmission and select the gear with the proper ratio.  The theoretical (it's all theory at this point) problem that I still have to solve is incorporating a clutch into the PTO shaft between the tractor and the differential so that the driveshaft can freewheel when the PTO is not engaged, and to prevent shockloading the PTO when I engage it on the tractor.  I'd be very grateful for any ideas on how to incorporate some type of clutch into the driveline, as well as any other ideas regarding efficiently moving logs up steep hills.  

Thanks!

[Nealm66]

I'd consider buying an older log skidder and selling it when you're done? 

[thecfarm]

That tractor is a small one. Yes it can haul what you are doing now. But start to haul more and things can happen. Kinda like the tail wagging the dog.
You also have to get the logs up onto the trailer.

[DMAK]

I'd love to use a skidder, but the owner of the land doesn't want anything bigger than what I have operating in there.  

The tractor has a loader which I use to load the logs on the mill, and could also load logs on the trailer.  It's only about a 30 foot hill that is the crux of the whole operation.  I would only engage the trailer drive axle for that 30 feet, and if things got sporty I could always just disengage the PTO and ease back down the hill.

[Hilltop366]

Use to be a bunch of those, DIY power trailers around here, all the ones I seen used a manual transmission.

I believe I've seen some with a linkage from the transmission shifter going up the trailer frame with a leaver near the tractor so you can reach back and put it in gear then turn on the PTO to power the trailer. Might have to slowly roll the trailer a bit to align the shift dogs in the transmission.

These were used on standard transmission tractors, what complications are created with a HST I'm not sure but any hydro lawn tractor I have had it is a big no no to tow the tractor without disengaging the transmission first which is a situation that you might get into with power to the cart wheels not synchronized to the tractor, I would talk to Kubota first before trying it.   

[Firewoodjoe]

Hydraulic motor? No drive shaft and no worry on synchronizing everything. 

[Crusarius]

I'm with Joe. sounds like a perfect candidate for hydraulic drive. I would think a proportioning valve could match the speed pretty close.

[Southside]

Agree on the hydraulic motor, but more importantly agree that this is a potential disaster in the making. 

Not only do you have to go, you need to stop, and if you are sliding backwards down a hill with a loaded trailer and multiple axles fighting each other the odds of a jackknife and rollover are increasing by the moment.

Another option is to use a 3 point winch to skid the bigger logs up the hill. You could devise a nose cone to reduce plowing and keep the end clean for your mill. 

Just imagine the pucker factor and coordination it will take to keep the throttle, clutch, PTO, steering, brake, etc all perfect when you are 3/4 of the way up the hill and you suddenly break traction and start sliding backwards. That log and trailer are going to look a lot bigger suddenly.  

[Riwaka]

Tractor /powered wheel forwarder trailers are usually run with a ground speed PTO on the tractor.

This is an old log truck, cab removed and tractor PTO powers the wheels through the truck differential. (tandem drive)

Valtra T174 with ground driven log trailer - YouTube

[moodnacreek]

A hyd. wheel motor connected to the diff. on the trailer SOUNDS like the way but your tractor would need the right flow and pressure. This would be aux. power on the trailer for bad spots and would most likely need a valve to allow it to bypass when not needed. I think the answer is a big tractor, 4x4, diff lock and maybe chains.

[Ljohnsaw]

I think the safest would be a winch on the front of the tractor. Either a straight pull or a snatch block if you need more umph to make it up. If using a snatch block with limited winch cable, use some chain, cable or tow straps on the snatch block to your upper anchor and reset as you climb the hill. Not the fastest but I believe it would be the safest.

[Andries]

When I had a close look at the video posted by Riwaka, it looked like the PTO went to a transmissiony-looking lump of metal, before the driveshaft went to the back axles.
It's a cool looking rig, and looks pretty darn rugged too.

[Riwaka]

The Finnish Company Black Bruin teamed up with a German company for a hydraulic drive for tractor pulled log trailers.

bpw-agro-drive-hydraulic-drive-axles-take-off-with-black-bruin

The trailer video in my previous post uses a Road Ranger gearbox (modified) 

[DanielW]

There are a few trailers like that driven by hydraulic motors around me. I suspect someone local used to make them. Getting the speeds right and having appropriate flow is key. Most of the time they're just used to 'help' it along when things start to slip, so if the speeds aren't synchronized perfectly it's not a big deal. You'd want one heck of a hydraulic system with good cooling to run one continuously.

As you mentioned, going with PTO would need further reduction. If you're running it at a lower idle (maybe 350 RPM PTO speed) and thee rear end you choose has a 4.10 ratio and 16" truck tires, it would be driving at 7-8+ MPH - faster than you want to take a lot of logging roads at - especially in a smaller tractor with heavy loads on a steep slope. It probably wouldn't be too hard to put a jack shaft in there with another 2:1 reduction. One of the old Massey tractors with the ground-drive PTO option would make a good tractor for one of these - if you sized it right it would always be synchronized, regardless of what gear you were in.

[woodman52]

Another solution to your problem (getting up one 30 foot hill with a larger load) is to bring your larger load to the base of the hill, unhook some,  drag up what you can,  then bring up the rest.  Rehook and carry on with your larger load. This would take some time but not much more than loading and unloading the trailer and be safer. 

[woodman52]

The other solution would be a pto winch. Bring your larger load to the base of the hill, let the cable out as you drive up, winch in. Carry on. This was already mentioned but I thought I would say it again as I have used this method and it works well 

[47sawdust]

Older MF geared tractors had ground driven PTO.Their are youtube videos of one pulling a peat trailer in the UK.
Kubota also had ground driven pto on on the M4000, M4500 and M4050.Probably other models in their respective families.These are early to mid 80's vintage tractors.I had an M4000 with creeper rear and with chains it would go anywhere.
The ground driven trailers are pretty impressive but you will need a larger,gear driven tractor.
A Polish company still makes one but it requires a LARGE tractor.

[Oliver05262]

My thoughts run to the old adage of "go light; go often".  Seems safer to me. 

[scsmith42]

My concern would be running out of horsepower on your tractor.

The mower power diverted to the log trailer, the less available for the tractor.  

Ditto the advice re hydraulic motor for the trailer.  Seems the easiest method.  

[John Mc]

If your problem is spinning the wheels on that upgrade (as mentioned in your initial post), why not just add some studded "euro-style" chains on your rear tires. It might add enough traction to dela with your issues. It also comes in handy when towing other trailers that may not be powered - both in getting up hills and in helping to avoid getting pushed around when coming down hill.

[Joe Hillmann]

I am in the process of building a pto powered trailer for my speceffic tractor.

Mine doesnt have live pto.  So when I push in the clutch the pto stops spinning.

The trailer is based around the rear end(transmission, pto, diff, final drives, and wheels of an identical tractor).  I turn the trailer backwards and connect both pto's together.  As long both transmissions are in the same gear and their pto's are turned on the trailer tires are powered.  if I turn off either pto the trailer tires are freewheeling and the pull tractor can be put in to any gear.

The idea probably wont work for you(you probably have live pro and dont have an identical tractor laying around for parts.)