4x4 Question

[SPYDERLK]

Fair enough ... I think. You proposed my "absolute" statement was flawed but, you can only presume that your stance can be proved with a mic. I accept that it is possible to prove it that way. I see no contest ... unless you are willing to prove your point by performing an experiment, such as the one I performed that was proposed by the fellow that I was ACTUALLY responding to, and QUOTED.

I believe the context of this thread, and my reply, probably not withstanding my "baiting" punctuation, are in harmony. If you'd like to dwell on my single sensational comment, feel free to do so. I have plenty of time. The key issue , to me, is, is there any REAL reason to NOT to be in 4WD when on a non-paved/HIGH-traction surface. In my view, no one has provided ant evidence to that end, eventhough I performed the challenge to which I replied (and quoted).

Cheers!

Heres some real reasons:
It uses more fuel.
It uses more tires.
It causes more turning radius and ground disturbance.
It causes more stress, heat, and wear on the entire system.
It requires more HP constantly.

 

[Soundguy]

Hmm.. I see we are at the point of hammering out minutia... that probably doesn't serve much at this point.... probably time to move on.

Soundguy

 

[N80]

All I can say is that from an engineering standpoint, the more stress a part is under. the more it will wear compaired to a similar part not under that load.

Soundguy

That is undeniably correct. But from there we probably have too many other variables to come up with any one single rule in regard to use of the front drive train.

It is my assumption, based on what I know about my specific make and model of tractor, that using the front drive constantly, in the proper conditions as outlined in the manual, that it should last as long as any other component on the tractor. And given that my manual only hints at one single condition under which using the front drive might cause problems (to the tires, it says), it would seem that I can keep mine in 4wd at all times unless I'm driving on pavement and expect not premature wear. (Soundguy, I know you didn't suugest premature wear, but others did and still are. And I agree that if I never used it it would never wear.)

Now, other people have tractors whose manauls say take it out of 4wd any time it is not specifically needed. I'd say those folks really need to do exactly what their manual says, there has to be a reason for it saying so.

Finally, I think it is also safe to say that for my specific make and model of tractor that you can add wear to other components when you get yourself into situations in which you should have been in 4wd.

I guess that summarizes my position on the matter, but if I had to boil it down to one statement I'd say "do what your manual says do."

How many more posts do we need before this thread sets some sort of record?

 

[JerryG]

All a person has to do to know that there is stress, binding, increased pressure or what ever is to look at the number of posts over the years that have ask how to get the 4wd lever to disengage easier. They are almost always told to lift the front with the loader, backup, straighten the front wheels or check the air pressure in the tires. If there weren’t any stress, binding, pressure or whatever they wouldn’t need to do any of these maneuvers.

 

[schmism]

put me down for flipping the lever back and forth all the time.

on for loader and ground engageing work (ie my back blade)

off for tight turns on the grass because it tears up the grass. ive watched the front inside tire with it both in and out of 4x4. when in there is aprecable scrubbing involved because the wheel cant spin fast enough when in 4wd.

 

[RayH]

A picture is worth a thousand words.
Here is the exact reason why it is hard on a drivetrain, truck or tractor, to turn in 4x4 on hard packed surfaces. http://home.comcast.net/~eliot_www/4wd.gif
Its not hard to imagine that the whole drive system, front and rear axles and transaxle, are effected. The front and rear axles are being turned the same speed but traveling different distances. This is why it either slips (scuffs) or binds when turning in 4X4. The more traction, such as on concrete, heavily loaded, the more binding and stress is put on the drivetrain.

 

[ovrszd]

All a person has to do to know that there is stress, binding, increased pressure or what ever is to look at the number of posts over the years that have ask how to get the 4wd lever to disengage easier. They are almost always told to lift the front with the loader, backup, straighten the front wheels or check the air pressure in the tires. If there weren’t any stress, binding, pressure or whatever they wouldn’t need to do any of these maneuvers.

Dang good point Jerry!!! Wish I had thought of that example. It's the same with some Jeep people. I've saw them destroy their transfer case shifter linkage yanking on the lever to get it to disengage right after completing a short turn. What do you say to people like that???

 

[N80]

A picture is worth a thousand words.

Well, all that assumes locked front and rear diffs. Open diffs, HST and center diffs in fancier 4wd (SUVs, some trucks) takes a lot of those stresses out of the picture.

Regardless, I don't think _anyone_ is arguing that it is a good idea to run a 4wd tractor with the front driveline engaged on pavement or any surface in which the wheels cannot slip a little.

 

[ovrszd]

Well, all that assumes locked front and rear diffs. Open diffs, HST and center diffs in fancier 4wd (SUVs, some trucks) takes a lot of those stresses out of the picture.

Regardless, I don't think _anyone_ is arguing that it is a good idea to run a 4wd tractor with the front driveline engaged on pavement or any surface in which the wheels cannot slip a little.

Sorry but the binding I described has nothing to do with locked diffs. Although locked diffs will make it worse, they are not the root cause. And we've totally beat the cause into the ground on this thread. Even have a picture posted now to describe the problem. If it's not understood by now, it's not going to be understood.

Edit: N80, if you believe that a locked diff could contribute to binding the driveline, why is it that you can't seem to believe that an engaged MFWD can cause the same binding?? A locked diff is simply a MFWD engaged, turned sideways on the machine.

 

[SPYDERLK]

Dang good point Jerry!!! Wish I had thought of that example. It's the same with some Jeep people. I've saw them destroy their transfer case shifter linkage yanking on the lever to get it to disengage right after completing a short turn. What do you say to people like that???

Ya cant argue with em. - - As I see it the main problem is the owners manuals that say "Stop the tractor when engaging or disengaging 4WD". This is safer than engaging while turning, or while going fast or slipping which should never be done, but applying this rule across the board eliminates the telling experience one gets when disengaging in varied circumstances.
Going straight gives some resistance because the fronts are set up slightly overdriven to "stretch" the tractor. This gives good small correction steering response. Backing up "compresses" the tractor to the same effect. A neutral stress point, giving easy disengage, is reached quickly after changing direction as stretch yields to compression.
A slight turn of just the right radius will bring front/rear into a complete neutral stress match and give easy disengagement.
A hard pull, or particularly a hard push or a hard turn, will make disengagement quite difficult.

A mental picture of what is happening, and a little experimentation are good tools to find easy, and any easy to disengage implys easy safe engagement as well.
Larry