Tires Spinning Tires

[THEBUS]

If I try to move something heavy - or push over a large stump - should I loose traction first and spin the tires or should the engine start to bog down? If I just barely push down on the hst pedal the tractor bares down but will not spin the tires. I have it in the lowest gear - "I" and in turtle. I also have it locked in 4wd with the rear diff. locked. I was under the impression that weight was the limiting factor in compact tractors which made me think the tires would spin if you were trying to move something too heavy. I have a TC40D with loaded R4 tires. Just curious what all of your experiences are.

 

[Bird]

What kind of rpm was the engine running? If the rpm was up around PTO speed, I would expect you to be able to spin 3 wheels when you encounter an immovable object. I think the only time I could not spin the wheels was when I hooked a scarifier on the box blade under an immovable tree root, then lifted with the 3-point hitch enough to really put some down pressure on my tires. I got enough traction that way that I didn't have enough power to turn the wheels.

 

[THEBUS]

I've tried it anywhere from 2500 rpm's to full throttle with the same results.

 

[Bird]

I'm sure not going to say there's anything wrong with your tractor because I don't know enough about that model, but I'm surprised that you weren't spinning your wheels.

 

[DVerbarg]

If you are at or near 2700 RPM (PTO speed) on the TC40D and have the range selector in "I" and are in turtle you should be able to spin the tires, IF the hydro pedal is NOT pushed down all the way. It the engine bogs down let up on the pedal. Pressing the pedal down does not apply more power but rather "shifts" to a higher range increasing the speed but decreasing the torque.

It took me a little time to adjust my natural tendencies from wanting to use the pedal like an accelerator to using the pedal more like a infinitely variable "range of gears".

There have been some discussions about this (with many good illustrations) in the past which was a big benefit to my understanding.

 

[THEBUS]

I am just barely pushing down on the hst pedal and the tires don't spin. I have read as many posts on this as I can find and believe I understand the way the hst works, I just don't understand why the tires don't spin in this instance.

 

[Mosey]

It seems odd to me that your tires are not spinning. I have tried to pull stumps with my TC29D in low range 4wd with the rear diff locked and the tires will spin before the engine bogs down much. I have been able to not spin my tires before the engine stalled when I was digging with my rear scoop in clay. The tires were getting great traction and the scoop was digging in and pulling down on the rear of the tractor. I was at about half throttle in mid range 4wd with the rear diff locked and going in reverse, so the front end didn't try to go up. The engine bogged but did not stall, apparently the hydro drive bypass kicked in, and the tires did not spin. I posted here about it (see the post "Plowing & pushing HST to the limit") and others said that seemed normal.

 

[DVerbarg]

There are some times when my traction is great enough to stall the engine without spinning the tires. The dirt and moisture have to be just right with lots of weight on the rear wheels. This is an exception though.

I would have my dealer look at it and see what is wrong.

 

[CSAW]

I believe if everything is working correctly and you are at a high throttle setting you should either loose traction, stall the engine or or break something. Unless there is some kind of pressure relief such as the one used in the loader circuit. If this is the case maybe it is not set correctly. If not the fluid is bypassing something else.

 

[JJT]

David hit the nail on the head. If the conditions are right my L3710 will stall before breaking traction, (hard dry ground). But if the ground is the least bit wet, or lose, I'll spin the tires before I run out of HP.