TC 30 Four wheel drive system

fctadam · Feb 9, 2004

How does the four wheel drive system work on these compact tractors? I keep seeing 4wd = front wheel assist, and I’m not sure what that means. I definitely want a tractor that has a fully functioning four wheel drive system with power going to all the tires. Is that what these have, or is it some kind of all wheel drive? I'm so confused.

Bob_Skurka · Feb 9, 2004

They have 4 wheel drive. But they typically will not allow wheels to free spin and the systems typically move power to the wheels with traction. Most also have a locking differential lever or pedal so you can engage all 4 wheels regardless. Generally, any compact tractor will go into places, and then get back out of places, that you would not consider taking a 4x4 truck.

fctadam · Feb 9, 2004

So there is a 4 wheel drive for all four wheels to get power, and most have pedal for locking differential which makes both rear wheels have power. So you have a choice of both real wheels with power, and a full time four wheel drive?

Bird · Feb 9, 2004

( I definitely want a tractor that has a fully functioning four wheel drive system with power going to all the tires )

Someone can correct me if I'm wrong, but most of the CUTs do not have that (although it's available on some larger tractors). You have power to both axles when you're in 4WD. But both axles have differentials, so you could be spinning one rear wheel and one front wheel. Then they have a differential lock (step on a pedal) for the rear axle, so then you have power to both rear wheels and one front wheel if one is stuck. I'm not sure how big a tractor you have to go to, to also get a locking front differential.

Now that's what I'm familiar with. Do any of the small tractors have a locking front differential?

Mrwurm · Feb 9, 2004

Sounds right to me Bird. That's exactly how I understand it.

fctadam · Feb 9, 2004

Still lost, how does that of the compact tractor compare to a pick up truck?

If the tractor is in four wheel drive all four wheels have power from the engine spinning (powering) them, correct? Like the rear wheels aren’t pushing the front wheels. If something hangs it up (gets stuck) then certain wheels can spin faster than the tires with traction, correct? If you then press the differential pedal, it locks all 4 wheels or the rear wheels together? Once locked then power is taken away from any wheel that is free spinning and given to other tires in need of power. The locked differential eliminates tire spin when stuck? What is a differential and how does it work?

Am I even close? I never thought about how my truck worked I just always slapped it in 4 hi and went through the mud.

higgy · Feb 9, 2004

It works the same as your truck for most situations.

If the tractor was stuck it will spin the front and the back tire that has the least traction, just as a truck does. The locker that others have talked about locks the diff so the power on the back axel is forced to both back wheels and "locks them together" if they spin both will spin at the same time.

The front does not have a locker and will spin at the wheel with the least traction. This can go from side to side as you start to get unstuck depending on the traction at any given time.

This is more than you will have with your truck unless you have lockers on your truck, and if you don't know about them you most likley do not have them. 4X4 is a misnomer, there is power provided to both the front and back axel through the transercase to the diffs. If the diffs are limited slip that will help to keep the power to more than two wheels.

These tractors are fantastic at being able to go placese that you would not take a normal 4x4 truck.

Dane

NIXON · Feb 9, 2004

Fctadam
4wd in most cases is a myth . Most 4wd vehicles have what's called an open differential . An open differential by it's very nature puts power to the wheel with the LEAST resistance .
But the good news is most 4wd tractors have selectible locking rear differentials , allowing power to be put to both rear wheels equally . So basically you get 3wd /forums/images/graemlins/smile.gif
A front locking diff. may seem like a good thing , but it will definately affect your steering (you'll go straight no matter how you steer ) I think you'll find even without locking the rear diff. on a tractor that while it's in 4 wd traction will be very much improved . Locking the rear diff does improve traction dramatically , but it does affect your ability to maneuver. one thing a tractor does have over a pickup in most cases is ground clearance , better tires (given the task ) and gearing . so overall traction will be better . I Hope this makes sense to you . John

Bird · Feb 9, 2004

( What is a differential and how does it work? )

The differential is named that because it allows the two wheels on that axle to turn at different speeds, or roll different distances as in turning, without one or both having to slide. So, yes, the tractor "4WD" will work just like your 4WD pickup if the pickup does not have a "limited slip" differential. If you do have the limited slip rear differential, then the wheel without traction can only spin a little ways before power is shifted to the other wheel. The tractors that most of us are familiar with do not have a limited slip differential (although some tractors do), so instead you have to step on the pedal to lock the differential (same result as having a solid axle), so now instead of one wheel spinning a little ways, then shifting power to the other wheel (as does the limited slip differential in a pickup), neither tire will spin at all without the other one turning the same amount.