How does an HST compare in pulling power with the same tractor and a gear trans?

[CobyRupert]

How does a HST compare in pulling FORCE with the same tractor and a geared trans?

I think a lot of the answers here are for that question.
The HST might deliver more force than the 1st gear of a manual transmission. Plus it can probably be more smoothly applied than a clutch transmission.

 

[LouNY]

Back in the day, I was looking to buy a NEW dozer... I already had a hystat dozer and just wanted something a bit bigger/newer.

My trip to the deere dealer, I learned that hystat dozers were pretty much junk! He explained to me how in many ways the power shift dozer was MUCH better and more efficient, he talked Case dozers down because they had hystats!!

Funny thing is, a couple years later pretty much all the deere dozers had hystats!!

SR

I see that Cat is still using Power Shift transmissions once you get out of what they call small,
I believe that D6 and up are all power shift, hydrostatic in the smaller ones.

 

[Jstpssng]

]No need for pulling duels. [/B]Both have been dyno tested and gear is approximately 10% more efficient and more HP delivered. Reliability testing shows HST wears faster. Repair data also shows less repairs even on glide shift gear transmissions. You also take a significant PTO HP hit.

Even with obvious gear transmission advantages my personal preference are HST drive for convenience. Even though if doing loader and material transport work one still does a fair amount of shifting with the gear ranges.

Ah, but it's more fun that way!!!

 

[zzvyb6]

Many years ago, the fuel economy push in cars lead to the development of the "Lockup Converter". This magnetically connected the motor to the transmission and bypassed the torque converter (pump). Seems like that would work just fine for smooth transitions from stopped or upshifting, plus the savings in fuel from torque converter slip and the avoidance of excess heat generation. Two equivalent machines with direct drive ought to then be the same dyno power.

 

[Professor Marvel]

One thing no one has mentioned that I myself forget at times is that pushing your foot down on the pedal of the HST is not the same as the gear. On the HST you are in essence changing the gear ratio. You are pushing fluid faster. With the gear you are creating more HP through the increased fuel. When I start to bog down a little going up the hill I am dragging I have to remember to actually ease up on the pedal of the HST. Just one more thing to add to the pulling power mix.
I myself far prefer HST despite it's shortcomings.

 

[k0ua]

How does a HST compare in pulling FORCE with the same tractor and a geared trans?

I think a lot of the answers are for this question.
The HST might deliver more force than the 1st gear of a manual transmission. Plus it can probably be more smoothly applied than a clutch transmission.

Go push up against a tree (NOT recommended, but people do it, including me) with the intent to push that tree over. I have done it with both types of tractors. I have owned 3 gear and 2 hydro tractors. I can tell you which one I prefer. The Hydro hands down. Why? you ask. Because you can apply the force gradually without wheelspin and without clutch wear. The tree does NOT start to shake back and forth and has less tendency to drop limbs on your hood. That's why. Which one do I prefer for gently getting a pallet out of the bed of your expensive pickup truck with your pallet forks? Yeah, the hydro wins hands down. Going slow and applying power gently is hydro territory. Plowing ground and getting maximum fuel efficiency, is gear territory all the way.

 

[Sawyer Rob]

I see that Cat is still using Power Shift transmissions once you get out of what they call small,
I believe that D6 and up are all power shift, hydrostatic in the smaller ones.

I believe it's because they are looking at fuel efficiency...

It's a big deal when you are burning as much as they do.

SR

 

[Industrial Toys]

It's also whatever the current "TREND" is. Don't look at cost of ownership of various techological disasters, just fuel consumption figures.

 

[mcfarmall]

Messicks did a video of two identical tractors with the exception that one was a gear and one was a hydro and the gear outpulled the hydro by a significant amount. Neil used a strain gauge hooked to a giant concrete block buried in the ground and both tractors had R1 tires on them.

Tractor Pulling Test - Gear Drive VS Hydro-static - YouTube

 

[Slowpoke Slim]

Messicks did a video of two identical tractors with the exception that one was a gear and one was a hydro and the gear outpulled the hydro by a significant amount. Neil used a strain gauge hooked to a giant concrete block buried in the ground and both tractors had R1 tires on them.

Tractor Pulling Test - Gear Drive VS Hydro-static - YouTube

True.

But if you actually watch the video, good old Neil there put the hydro trans in high range for the test.

That is what K0ua was talking about in his first post.

Only a MORON would do that.

Put BOTH tractors in their lowest gear, or range, and it will be which one holds traction the longest. Which comes down to weight of machine and tread type of tires.

That's kind of the point.