texasjohn
Super Member
I'm 4WD all the time for traction/braking except when on pavement.
All my tractors go in easily if im moving. If they dont go in at a standstill, moving ahead slowly will get them in. Most come out easily too when going straight. If not, I accelerate then let off and quickly operate the lever. Works every time.RalphVa said:Biggest reason is safety. With 4wd, you also get 4 wheel brakes. On my tractor, it has to be just so (all tension off the gears, etc) to get the thing in and out of 4wd. If I left it in 2wd, I can see myself getting into a ticklish situation needing 4wd and not being able to get the lever to go. I leave mine in 4wd unless I go all the way down my driveway. Half way? It stays in 4wd.
Ralph
PILOON said:Someone mentioned 4 wheel braking.
May I correct that statement?
Most tractors that I know of only have brakes on the rear wheels.
SPYDERLK said:None of my 3 Kubotas, nor any of my tractors have as tight a turning radius in 4wd as in 2wd. The difference is in the 5-10% range unless you use the brakes in 2wd.
larry
john_bud said:Sorry, these discussions make my brain hurt.
1) 4wd is slightly harder to turn and will be slightly wider (about the 5-10% mentioned above)
3) 4wd does use slightly more fuel per hour. But you will need to keep tight records to learn just how much more.
Yes, it must be some difference in models. Theres some sort of magic going on. The problem that arises with 4wd turning is that the tighter the radius being turned the more discrepancy exists between the summed distances moved by the fronts and the rears. The tighter the turn the further the fronts go compared to the rears. Fronts that are well overdriven are great for turning, but fronts that are driven just right to work neutrally along with the rears when going straight are not. In turning these fronts are being pushed by the rears, but being forced to run at the same tread speed as the rears by the linked system. They slide causing a wider circle. Normally, fronts are overdriven slightly, gently sratching along trying to stretch the tractor. More would be better for maneuverability, but with a loaded loader and counterweighted tractor the forces on the drivline would be abusive when going straight. It becomes a balancing act. I dont see any way this system dichotomy can be fully resolved in a system hard linked front to back.N80 said:There must be something wrong with your 3 Kubotas. In a bevel gear system there is absolutely no reason for the turning radius to be larger in 4wd in 2wd. The angle at which the wheels turn is identical and there is no palpable binding of gears. Again, I've measured it on mine, not eyeball, but with a tape measure. No difference. None. It is certainly conceivable that there is a difference between models. Mine is an L4400.