Got my 4 wheel drive tractor a few weeks ago and was mowing on a small slope going forward and tried to back up in some wet grass and got stuck. I was in 2 wheel drive and the left rear was spinning so I put it in four wheel drive then the left rear and right front started spinning. So I locked the rears and got unstuck. I would have thought that when the front starts to spin an antispin differential would kick in and the other front wheel would try to grab. It dawned on me that the fronts don't lock so basically the most I can get is a 3 wheel drive. Am I missing something here?
Four wheel drive is not really four wheel drive?
- Thread starter edrobyn
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BethesdaEC
Gold Member
You are correct, the front is a standard differential with no lock.
jinman
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No, the same as saying 2WD when referring to an auto. It's really 1wd if you get into ice or mud.
BTW: A poor man's differential lock is using differential brakes. On old 2WD tractors without diff-lock, we used to apply the brakes to the spinning wheel to force the wheel with the most traction to pull. It works well, but you can't do that to the front wheels. Also, someone pointed out to me recently that even though you have only 3wd when driving forward, when you brake, you have full 4 wheel brakes because if the driveline to the front differential is locked, one wheel can't turn (unless the other wheel turns backwards).
art
Super Member
On compacts it's normal that the front doesn't have limited slip till you get to the larger tractors.
We have often been reminded of the three wheel drive at best when in slippery conditions.
We have often been reminded of the three wheel drive at best when in slippery conditions.
SPYDERLK
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On a standard [open] differential it may seem that only one wheel drives. But actually both do. Its just that you only get twice the thrust that the wheel with the lesser traction can provide. If that wheel has almost no traction ... well, twice that isnt much.
larry
larry
slowzuki
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Was going to say exactly what spyderlk said. Practically speaking, I've got a large MF with front and rear diff lock. These aren't hard numbers but using 4wd, 4 wheel lock as the 100% traction reference while pulling something, unlocking the front diff barely makes a difference. Unlocking the rear might knock you back to 85%, putting in 2wd gets you back to about 60%.
Using the front loader, or backing out of somewhere pointed downhill you were sinking into is a whole different story. The front unlocked might knock you back to 80%, rear unlocked, 70%, 2wd 20%.
Using the front loader, or backing out of somewhere pointed downhill you were sinking into is a whole different story. The front unlocked might knock you back to 80%, rear unlocked, 70%, 2wd 20%.
Mark Page
Platinum Member
I've found the same thing to be true with pick ups. I've owned Ford, Dodge and Toyota. I've never been able to get more that 3 wheels engaged. Very frustrating when you get hung up.
RaydaKub
Veteran Member
Nope. They still have differentials in front and hub locks sure doesn't guarantee a limited slip differential in the back.
oldballs
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I remember that thread and didn't really, really understand it then either. But, y'all, thanks for trying. Even with my (2WD) F-250, when stuck in the mud, it seems like just one rear wheel was spining with the limited slip rear end. But my neighbor's McCormick always pulled me out...I guess that makes a four wheel drive. or are we back to three wheel drive his two...and my one???JoeL4330
Platinum Member
I have a few 3wd vehicles but my Grand Cherokee has electronic limited slip front and rear (as well as traction control, if that counts)...it goes good
TripleR
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My son had one of his 4WD set up with lockers front and rear as he ran mud quite a bit. It was great for straight line running, but not turning. I have the same settings on my Rhino and Grizzly and the extra wheels pulling makes a real difference.
Our M8540 has limited slip front and it will go right through stuff that would leave our CX80 stuck.
IndyIan
Veteran Member
I read some of the Mahindra's have front diff lock but I don't know how far down their line they go with it.
My Atv has a front diff lock and it does make a difference, but maybe only as much as running Ag tires vs Industrial tires?
Unlike ATVs, trucks or any vehicle with suspension, the front pivot axle on a tractor does load the front tires equally unless you run out of travel, so its not as big an advantage as it is with an ATV, etc.
For me it wasn't a consideration when buying, as I don't plan on mud bogging very often if at all. I have a few skidder ruts in my woods from the previous owner and I don't want to duplicate that...
SPYDERLK
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The 7520 does not, limited slip instead. Pretty good but I sure wish I could lock sometimes ... esp when 1 front has very little traction. I think several Kiotis have a front locker.
larry
DiskDoctr
Platinum Member
My 2004 3510 does NOT have limited slip or front diff lock. If I get into high snow (by accident), or on ice, I can spin one front tire with no hope of escape!
- JC
