Why turn 4wd off?

[SPYDERLK]

The front differential never locks, there is no lock mechanism on our CUT size tractors. there is no center differential on most of our CUTS either (some do have, but not many) On Hard surfaces (asphalt, or concrete) when making turns there can be binding (torque windup) between the front and rear. This results in tire wear, for sure and some extra strain on the front differential. But the danger of going down a steep hill in 2WD with a load in the bucket is very real, even on pavement if it has some loose gravel on it, the rear tires can and will break traction, resulting in a runaway if the hill is steep enough, and there is enough gravel, or going down a grassy slope, or anything that reduces traction. Having a heavy ballast on the back will help prevent this, but don't count on it. 4WD is your friend to prevent this. Been there and done that and have survived. What ever the heck you do, drop the bucket, drop the ballast, keep the steering wheel straight, don't swerve or you will surely overturn. Several guys on here can testify what happens when you swerve to miss something.

James K0UA

I saw a front diff lock on one of the bigger Kiotis. I wish I had that option on my 7520. :licking:
larry

 

[Gary Fowler]

I can turn several feet shorter in 2wd vs 4wd.

I think this depends on the tractor. With my Yanmar this is true in 4 WD it just doesnt want to turn without digging the tires but with my LS, the tires turn much more of an angle and it really doesnt matter whether it is in 2 Wd or 4Wd it turns just about the same without tearing up the grass like the Yanmar. I have to use the brakes to get the front end to come around with the Yanmar, but I can turn sharp without the brakes with the LS, just a bit sharper with them though.
I usually try to mow in 2 WD but all FEL work is 4 WD. It isnt a good idea to run in 4 WD on pavement regardless of load. You shouldnt be on pavement with unstable loads to start with and I dont think I have ever seen a pavement with a hill so steep that you could loose control on one, 8% grade is about the max allowed on public highways. Now if you have your own driveway paved, then I suppose you could have it as steep as necessary but the same thing holds true, the front outtracks the rear by 5% or so and if they are loaded heavy, then the rears have to skid. Either way you will put a lot of pressure on the drivetrain. Better to ballast your tractor correctly so you dont have to worry about lifting the front wheels. You can always drop the bucket if you start to handstand. I make it a practice to keep one hand on the FEL controls anytime I am traveling so I can adjust the bucket height quickly if needed like going thru a ditch I would need to raise it and then drop it back on the other side. I carry the bucket about a foot high when loaded so it doesnt have far to travel if I have to set it down quickly.

 

[blueriver]

For me its never been a hard decision ... If the Mfg mean't for it to be in 4x4 100% of the time they would not have made a lever or switch to engage and disengage.

 

[TripleR]

Some very interesting posts, but sometimes it seems we tend to over think things. I have operated tractors in a way guaranteed by some to cause catastrophic failure yet in over 50 years have yet to break anything in the drive train or blow an engine.

I think you are correct, however your comments makes me think of two things.

1. If we didn't over think things here we would probably end up reading the newspaper more thoroughly with our extra time and that could be really depressing instead of fun like reading about tractors and stuff.

2. I don't think I would loan you my tractor.:laughing:

1. Like I said, it is an interesting thread and I do not exclude myself; after all I took the time to read it.

2. You are a wise man indeed.:laughing:

I actually refuse to borrow equipment, but will rent it. I use my equipment hard, but do not abuse it. If it doesn't hold up, I don't want it. They are called tractors and work equipment for a reason.

... Yes. We apparently have experience with tractors of competent strength design for their entire functional envelope. There are obviously some that are not, since there are enuf substantiated reports of failure, sometimes repeated, to bear it out. For the sake of suitable machinery I hope those cases are more "unlucky" than ours are lucky.
larry

I suspect that some of the failures are the result of using the wrong equipment or using something outside the design parameters. I can't say that I haven't done this from time to time, but was willing to accept a failure as "operator error" rather than "equipment failure".

I imagine there are more than a few of us who hasn't at one time or the other pushed the envelope a bit; I just try not to make a habit of it.

I'm not sure about the "luck" part, but I have told my wife that some of the best decisions I have made were more the result of luck and happenstance than clever, informed decision making.:laughing:

 

[yandeereguy]

On hard packed surface like a concrete driveway or hard packed gravel I would leave it in 2wd..

5 days ago I was going up my driveway on my JD 870 (hard packed gravel) noticed some pretty good front tire slippage they are well worn compared to the back tires, about 30 feet after I noticed the slippage, I broke some gears in the front left drive housing

I had to tow the tractor with the front wheels up, back to my shop

It won't be a mistake made again $$$$$... my 2 pennies

 

[SPYDERLK]

On hard packed surface like a concrete driveway or hard packed gravel I would leave it in 2wd..

5 days ago I was going up my driveway on my JD 870 (hard packed gravel) noticed some pretty good front tire slippage they are well worn compared to the back tires, about 30 feet after I noticed the slippage, I broke some gears in the front left drive housing
I had to tow the tractor with the front wheels up, back to my shop

It won't be a mistake made again $$$$$... my 2 pennies

Cause and effect are probably reversed here. That breakage developed over time in an inadequate component.
larry

 

[tessiers]

I have replaced front final drives several times, I agree it was more operator than machine. I believe every major manufacturer recomends ballast with the use of front loader, I don't feel they recomend enough. With more and more HP in smaller and smaller tractors something has got to give, if the tires can't slip the gears will, eventually. The rear end and rear tires are the bread and butter of any tractor, if they weren't why have different sized tires and differentials. As the saying goes I did it 100 times and 99 it worked.

 

[techwrtr2]

My tractor is almost never driven on paved surfaces. The roads around our property are gravel at best. I still run in 2wd unless I specifically need 4wd. I've observed that even though my tires are sized correctly for the tractor, if I spend time running in 4wd on even dry gravel roads, there is binding and can be very difficult to shift out of 4wd. Not something I experience if on a truly slippery surface. As others have observed, the turning radius is greater in 4wd versus 2wd and I'm more likely to dig up the surface I'm driving on in 4wd. If I'm mowing, it's something I like to keep in mind.

As with so many things with equipment, there is no one size fits all statement as to what you need to do. Some have pointed out that their experience has proven it's best to stay in 4wd all of the time. Others like myself have found it best to use 4wd only when needed.

 

[Jerry/MT]

I've been reading a bunch of threads on here about safe (and unsafe!) tractor operation. One of the things I've read about and personally experienced is how useful 4wd is when going down hills nose-first. I don't have very many big flat spots on my property, and I'm often using the loader, so I pretty much leave the tractor in 4wd all the time.

At first, I thought it was like my truck, and the diffs locked when it was in 4wd, so you couldn't use it on pavement. But then I realized it's got a separate diff-lock lever, so that must not be the case. So that leaves me wondering? What's the down-side of 4wd? Why not just leave it on all the time and enjoy the benefits?

I leave our tractor in 2WD so that if I get stuck in boggy conditions I can use 4WD to extricate myself. If I get bogged in 4WD, I'm really stuck, and then I have to get another tractor to get me out.

 

[namesray]

short of starting a new thread, which i was going to do until i discovered this one, the other day i was skidding logs with my hst tractor and got to thinking about 2wd and 4wd. i was using 2wd and everything was going good. i was wondering if pulling heavy (such as skidding logs) with a hydrostat transmission, is it easier on the transmission to be in 4wd, so that there is an extra set of wheels helping to pull and taking strain off the rears, or is it ok to just use 2wd? which do you all think would be easier on the tractor with hydrostat transmission?