4x4 Question

[RobJ]

Regarding the turning radious. Kubota sort of "punts" on this one. My L2500 owners manual says 7.9' for both 2wd and 4wd. This is of course using the brakes. No real numbers in the book.

 

[Soundguy]

Here is a bit of irony for you.. Out of the ? 11 tractors i currently own.. and a couple more I don't own any more... All of them have been 2wd, except 1.

Guess which one I have been stuck in? That's right.. the 4wd model!!

High centered.. sunk to the axles, front and back..

My 2wd units keep me honest.. and keep me in terain i know I can get in and out of.. without a shovel and tow strap.

Soundguy

I think having 4wd contributes to MORE 4wd tractors getting stuck (just look at this site and the pictures and posts). With my 2wd I look and say, "nope, to wet". If I (as in me myself) had a 4wd I know for certain I would be tempted to give it a try. But these things aren't ATV's, a tractor usually sinks.

 

[Soundguy]

The kicker is the brakes.. Stomping on a single brake can often make you pivot on a tire, in place, depending on the tractor, making the front tires skid ( 2wd ) or chew and scuff ( 4wd ) in the same tight turn radious.

Soundguy

Regarding the turning radious. Kubota sort of "punts" on this one. My L2500 owners manual says 7.9' for both 2wd and 4wd. This is of course using the brakes. No real numbers in the book.

 

[SkyPup]

Sounds like one wheel drive may be the best of all based on the opinions expressed here!

Has anyone found two wheel drive too much for themselves and converted to one wheel?

 

[NewToy]

Sounds like one wheel drive may be the best of all based on the opinions expressed here!

Has anyone found two wheel drive too much for themselves and converted to one wheel?

I had a flat while in 2WD once, does that count?

John

 

[Soundguy]

2wd and no diff lock.. that's pretty much 1wd when the conditions are correct...

Soundguy

 

[whodat90]

Regarding the turning radious. Kubota sort of "punts" on this one. My L2500 owners manual says 7.9' for both 2wd and 4wd. This is of course using the brakes. No real numbers in the book.

Just for grins I went out and measured mine. Conditions: heavy tiller on the 3pt hitch, 110lbs of suitcase weights on the front. Freshly tilled soil (yesterday) with rain last night. Not mud exactly, but enough to stick to your shoes if you walk.

2wd: 19' outside to outside
4wd: 20' outside to outside

I attribute the small difference to the fact that with the heavy tiller on the rear the front tires had a tendency to plow through the soft soil rather than pull the front end around. In 4wd it pulled the front end around.


Wet grass, brush hogged last week:

Couldn't get an outside diameter measurement due to the marks left not being clear enough.

2wd: 6' inside diameter
4wd: 8' inside diameter

Definitely a significant increase from the inside measurement, but not so much when measured to the outside of the circle. I guess it depends on whether you need the tight turn to get close to something in the center or avoid hitting something on the outside.

 

[dtd24]

Man this thread is a hit. I haven't been able to log on in awhile, and was suprised to see it still going. I have been going in and out of 4x4 quite a bit. Switching it up a bit.

 

[BillyP]

Man this thread is a hit. I haven't been able to log on in awhile, and was suprised to see it still going. I have been going in and out of 4x4 quite a bit. Switching it up a bit.

Since you started this thread, do you have an answer to your own question?

 

[kyspartan]

Timber, your description of your truck system is a modern version of the full-time drive system of the 70s. It has no connection to your vehicle computer other than to trigger lights in the dash and engage the front axle disconnect if so equipped.

When in 2 wheel high, that's all the drive you have.

When it's in 4 wheel auto it is functioning as the previous mentioned full-time drive system splitting power to each axle. Similar to your semi rear ends when the power divider is unlocked. To prove this, jack up either end of your truck until both front or rear wheels are off the ground. Engage 4 wheel auto and try to drive off the jack. It will just spin whichever axle you have jacked up and won't move the vehicle.

When it's in 4 wheel high it is locked in 4 wheel drive and demands equal rotation of the front and rear driveshaft. Similar to your semi rear ends when the power divider is locked. If you jack the truck as described above, it will drive off the jack. This is what your B7800 has when you engage MFWD with the lever.

When it's in 4 wheel low it's locked in 4 wheel drive but is operating in low range of the T-case.

gm trucks still have front hubs that are disengaged automatically when you select 2 wd with a vacuum diaphragm and gm constant all wheel drive options on trucks and suvs are the same system they just remove the selector buttons and front hub actuator then charge more for it. as far traction control on the newer trucks it just applies the brake to the wheel the computer thinks is spinning faster than the other wheels