More torque for my Power trac?

   / More torque for my Power trac? #1  

stray

Platinum Member
Joined
Jan 18, 2004
Messages
710
Location
east TN
Tractor
Power-trac 422 2003 model and 428 January 2015 model
I started working on this set up before but at the time I didn稚 have much use for it. I recently have had a couple of jobs where I could have used more pulling power. Just a bit more torque would have made the difference. I know this set up will be controversial and could cause damage to wheel motors if (pushed too hard) but I知 willing to take that risk. If one is considering changing all four motors it wouldn稚 be much of a risk anyway. It will be nice to hear thoughts, comments and experiences of what flow, pump volume and pressure changes might take place. Wonder if it will help power or will the pump not have enough volume or the motor enough power to make a difference.
Four valve a few fittings and some hoses and it can be tried. In my case most of the time I would leave the PT in normal mode and in the few cases where I need that little more power I could switch the valves and use the torque mode. I have broken one wheel motor with the wheels reversed and going all out and then some to move a load of rock 3 times the weight of what I should have been moving. I still reverse the wheels at times but I am a little more careful.
Anyway comment and criticism welcome.
 

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   / More torque for my Power trac?
  • Thread Starter
#2  
Or maybe this Quick disconnect set up would take less room?????
 

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   / More torque for my Power trac? #3  
First, I need you to help me lay out a schematic for my PT, You did a great job, I assume you are using something like a drawing program or do you have a special program with all the pictures for connectors?

So, are you adding another pump? or are you plumbing a T connector, like a second output, to each side of the pump?

I would think that the hoses to the motors, the hose size would have to be increased either way...

What about, instead of adding to the 4 wheels, you divert the flow from the rear to the front wheels. Meaning make the tractor 2 wheel drive for those extra special moments.
 
   / More torque for my Power trac? #4  
From what I see, in one position, two motors will be in series with each other and in the other position, two motors will be in parallel with each other? Is that correct?

If so, when in parallel and one motor encounters an obstacle, its mate will get all the flow. Conversely, if one motor is on ice and spins, it will get all the flow and its mate will get nothing. It could take all the flow from all 3 other motors, couldn't it?
 
   / More torque for my Power trac? #5  
You can not usually get something for nothing. So. if you want more torque, go with larger wheel motors like someone else did. I believe he said the torque improved, but the speed will decrease somewhat. You could go with smaller diameter tires, but stronger wheels. There again you will decrease speed, and gain torque. You will lose some height from the bottom of the PT to ground. The wheel motors are rated at so much HP. and that is what you have to work to with. As with all the PT's, more power means bigger engines, bigger tires, bigger pumps, etc. If you have the room, use a larger engine, and larger pump, and either get larger wheel motors, or perhaps a two speed wheel motor. If you look at hydraulic motors in the catalog, you will see if you go with more cu in, the speed of the motor will decrease. You might even get by with the same engine, and larger pump, but you can not use all; your hydraulics at the same time. You will run out of HP.
 
   / More torque for my Power trac? #6  
From what I see, in one position, two motors will be in series with each other and in the other position, two motors will be in parallel with each other? Is that correct?

If so, when in parallel and one motor encounters an obstacle, its mate will get all the flow. Conversely, if one motor is on ice and spins, it will get all the flow and its mate will get nothing. It could take all the flow from all 3 other motors, couldn't it?

And that is the rub. The "limited slip' feature of the series connected motors is lost.

Still, it would be interesting to hook them up in parallel and see what happens.
 
   / More torque for my Power trac? #7  
Wouldn't rather have a flow matching device, to ensure that F/R, and R/L all got equal volumes of fluid for your high torque/traction issues? Clearly, not a feature you want enabled at all times because you'd scuff the heck out of most surfaces, but it would be akin to locking a differential.

All the best,

Peter
 
   / More torque for my Power trac? #8  
Not that this makes a hill of beans, but on my 1850, A hose goes to the front wheel, and then a hose goes to the back wheel, and then a hose goes back to the pump. - Same on the other side. I am still trying to track down the relief hoses and where they all go to...
 
   / More torque for my Power trac? #9  
I also wonder if you locked the wheel motors together and tried to turn, what the side loads on the wheel motor shafts would be.
 
   / More torque for my Power trac? #10  
Not that this makes a hill of beans, but on my 1850, A hose goes to the front wheel, and then a hose goes to the back wheel, and then a hose goes back to the pump. - Same on the other side. I am still trying to track down the relief hoses and where they all go to...

Case drains?
 
 
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