I have a good feeling this question has been asked before, but I see every Case BHL spin its wheels when the machine is digging with the backhoe and the outriggers are in the down position. Time and time again I look at one of the machines and try to picture why the wheels do spin, but without ever doing transmission work on one of these machines, the concept is hard to picture. I've come to the conclusion that its because of some miniscule connection between the transmission and the torque converter, but I still to this day haven't come up with a definite reason. If anyone has a definite answer, it would be greatly appreciated... this isn't for any machines I'm currently having issues with, its just for the sake of satisfying my curiousity (I hope yall can understand ) Thanks, Logan
I forget the answer but I do know when the 1-4 gear select is in neutral the wheels wont spin.
It's actually quite simple Hevy. First, operator leaves parking brake off, that way he can raise outriggers and move machine using boom. Second, as JS580 noted, manual gearbox is engaged in 1 - 4 gear which couples tranny with rear axles. Lastly, with engine running, torque convertor is still turning input shaft to drive line. The only part that is in neutral is the fwd/rev clutch packs. But since clutch packs are not totally friction free in neutral, it will cause the shafts to turn which make rear wheels turn. As soon as you drop it on the ground it will stop turning wheels.
Just an amusing aside, normally any good size fella can slow and then stop the wheels w/ one hand. My brother was running a 580 inside a paper mill, had the wheels spinning pretty good, when a secretary came out to ask him something. He said she wouldn't weigh 90 lbs soaking wet with her pockets full of lead. When she leaned in to talk to him, a wheel hooked her and the inertia shot her under the tractor and spit her out the back! It scared them both half to death, and gave her a good coating of mud, but didn't hurt her.
Lucky, he must of had the wheels well off the ground!
Thanks for the explanation guys! Always good to know the technical side of things, I also liked the little tidbit on why the operator leaves the parking break disengaged . Haha to the story as well, glad no one was hurt but I could see why taking all the force of the spinning wheel at once could be more dangerous than slowing it down at a slower rate with your hand. Thanks again, Logan