What do these mean

[geekfarmer]

I think I have been able to figure out what some of the terms mean.

CUT - Compact Utility Tractor
HP - Horse Power
FEL - Front End Loader

what do these stand fore

MFD/FWA
MFWD

Better yet, is there a magic decoder some place

 

[john_bud]

I know, I know, I know!

(I got my magic decoder ring out of a vintage 1958 box of Cracker Jack!)

FWA is Front Wheel Assist
MFWD is Mechanical Four Wheel Drive

 

[geekfarmer]

I know, I know, I know!

(I got my magic decoder ring out of a vintage 1958 box of Cracker Jack!)

FWA is Front Wheel Assist
MFWD is Mechanical Four Wheel Drive

And the difference between 4WD, FWA and MFWD is?

 

[dbear]

And the difference between 4WD, FWA and MFWD is?

They are frequently used interchangeably, but in actuality, 4WD refers to the full-time, articulated tractors. Front Wheel Assist (FWA) and Mechanical Front Wheel Drive (MFWD), at this time, are pretty much the same thing.

At one time, FWA was accomplished via hydraulic wheel motors instead of thru a mechanical drive shaft (MFWD). Both systems are 2-wheel or 4-wheel selectable.

 

[milkman]

At one time, FWA was accomplished via hydraulic wheel motors instead of thru a mechanical drive shaft (MFWD). Both systems are 2-wheel or 4-wheel selectable.

Are they 2-wheel or 4-wheel drive or 2-wheel 3-wheel drive?

 

[dbear]

Are they 2-wheel or 4-wheel drive or 2-wheel 3-wheel drive?

Not sure I completely understand your question, especially the "3-wheel" part, but here goes:

I believe a 2-wheel drive tractor does supply driving force to both its rear wheels (I could be wrong about that); while the front wheels merely provide directional control. Most larger CUTS, utility, and farm tractors have a manually operated differential lock that will force both drive wheels to spin at the same rate. Great when wanting to move in a straight line thru a difficult patch of soil, but not so good if needing to turn. That said, a diff lock is something I wouldn't want to be without.

MFWD tractors function the same as a 2-wheel drive tractor, but also allow the operator to engage driving force to the front wheels via a lever, switch, pedal, or knob (depending upon make and model) at will, or when conditions dictate. Said lever, switch, knob,...will usually disengage (or is it engage, I always get it backward) a hydraulic clutch, thereby coupling the front driveshaft drivetrain with the transmission thru means of a tranfer case. With the front wheels engaged, the tractor does have 4-wheel drive, in that both wheels are supplied with force (again, I could be mistaken). However, one is still able to turn quite easily because the front differential allows each to spin at a different rate if needed. Some manufacturers offer a front diff lock, either as standard or as an option, that functions the same as the rear diff lock, and that when used in conjunction with the rear diff lock would make one's tractor almost unstoppable, I would think.

Is this what you were looking for?

 

[dirtworksequip]

hmmmmmmm, I think 4 wheel drive is only two wheel drive unless you use the differential lock, then that would only give you 3 wheels driving. Two rear wheels and one front. You never actually have all 4 wheels driving unless there where lockers installed. Now I bet you are really confussed.

Sincerely, Dirt

 

[Harry c]

hmmmmmmm, I think 4 wheel drive is only two wheel drive unless you use the differential lock, then that would only give you 3 wheels driving. Two rear wheels and one front. You never actually have all 4 wheels driving unless there where lockers installed. Now I bet you are really confussed.

Sincerely, Dirt

Pretty common thought but technically not quite correct. The differential applies exactly the same amount of torque to each wheel on the axle. If one wheel can spin more easily than the other, it will spin while the other wheel APPEARS to be supplying no force. In reality it is providing the same force as the one that is spinning. Try this if you have a BH and FEL (it can be done with jacks but this requires no real work). Lift the rear wheels off the ground with the outriggers. Raise the front wheels with the FEL. Have a helper put the machine in 4 wd and put it in gear so the wheels spin. Helper will need to press the pedal if you have a hydrostatic. Use very low RPM. Stop one front wheel from turning with a gloved hand. The other wheel will turn. Apply some resistance to the wheel that is now turning and you will feel the wheel you're holding start to try to turn. The torque will be the same on each wheel but the one that can spin the most easily will spin while the other sits still. The only time both wheels will spin is when the traction is approximately the same for both wheels. If one wheel is on ice and the other is on dry pavement, it may take only 50 ft lbs of torque to spin the ice bound wheel. The wheel on the dry pavement would be supplied the same 50 ft lbs but would not spin.

A diff lock makes both wheels spin at the same speed regardless of the traction. With the diff lock engaged both wheels will spin even if the traction is not equal. In the ice illustration, the wheel on the ice will be supplying very little push while the wheel on dry pavement will probably shove you right along.


This illustration works on the rear as well. It's just usually easier to stop and hold the front wheels due to their smaller size and lighter weight.

If you try this, don't do anything dumb like get under the tractor or get yourself in a position to get run over! Don't grab a fast spinning wheel...etc.

 

[3RRL]

I think I have been able to figure out what some of the terms mean.

CUT - Compact Utility Tractor
HP - Horse Power
FEL - Front End Loader

what do these stand fore

MFD/FWA
MFWD

Better yet, is there a magic decoder some place

There was a thread in Owning and Operating a while back with lots of input on tractor acronyms. It might help?
Click on this...Tracto Acronym Thread

 

[Soundguy]

If one wheel can spin more easily than the other, it will spin while the other wheel APPEARS to be supplying no force. In reality it is providing the same force as the one that is spinning. .

Technically not correct either.. if we are in to nitpicking..

Jack up 1 rear wheel on a 2wd tractor.. put it in gear and go.. try all the gears.. let me know when you get it to move.. that wheel on the ground will set there and stare at you while the other wheel is doing doubletime along with the spiders... That's just how the diffy works...

Ya got to have -some- resistance on the 'free' wheel.

This is why using the 'steering' brakes (on some tractors that have them) can get you out of a mud hole where one wheel has no resistance..


soundguy

 

[rback33]

This is why using the 'steering' brakes (on some tractors that have them) can get you out of a mud hole where one wheel has no resistance..


soundguy

Yet another part of using the steering brakes I never thought of...

 

[RobJ]

Are they 2-wheel or 4-wheel drive or 2-wheel 3-wheel drive?

Watch this guy...I think he was kidding AND causing trouble.

BTW, your package is on the way. Good Luck!

 

[john_bud]

When I've been stuck in the muck up to the center line of the wheels, standing on the diff lock in 4wd - there are 3 wheels actively digging me in deeper. Both rears and one front. Wiggling the steering wheel will usually get all 4 wheels equally dug in so pulling out is a real chore.

jb

 

[AndyMA]

Technically not correct either.. if we are in to nitpicking..

Jack up 1 rear wheel on a 2wd tractor.. put it in gear and go.. try all the gears.. let me know when you get it to move.. that wheel on the ground will set there and stare at you while the other wheel is doing doubletime along with the spiders... That's just how the diffy works...

Ya got to have -some- resistance on the 'free' wheel.

This is why using the 'steering' brakes (on some tractors that have them) can get you out of a mud hole where one wheel has no resistance..


soundguy

Soundguy is definately right on this one. Think oif a 2 WD car. How many times have you seen one with one wheel on ice and the other on dry pavement where the one or ice or snow just spins and the car does not move. If there was any torque being applied to the opposite wheel the car would definately move. Limited slip differentials overcome this problem. somewhat

Andy

 

[AndyMA]

An option on New Holland TN tractors which have the electro hydraulic (switch operated) differential lock is also electro hydro differential of the front axle. Mine happens to have this and it makes a huge difference in slippery conditions. Actually in almost any conditions where you need the most "push"

Andy

 

[Harry c]

Technically not correct either.. if we are in to nitpicking..

Jack up 1 rear wheel on a 2wd tractor.. put it in gear and go.. try all the gears.. let me know when you get it to move.. that wheel on the ground will set there and stare at you while the other wheel is doing doubletime along with the spiders... That's just how the diffy works...

Ya got to have -some- resistance on the 'free' wheel.

This is why using the 'steering' brakes (on some tractors that have them) can get you out of a mud hole where one wheel has no resistance..


soundguy

OK Soundguy. Read what I wrote... We've said the same thing.

"If one wheel can spin more easily than the other, it will spin while the other wheel APPEARS to be supplying no force. In reality it is providing the same force as the one that is spinning. ."

If the free wheel has no resistance, it therefore is supplying no force, the restricted wheel is applying the same force. NONE. (Ignoring internal friction of course)
Actually, to pick a few more nits, even in the mud the wheel is encountering some resistance therefore it and the opposite wheel are applying some motive force. It may not be enough to move the vehicle but it's equal force on each wheel. Agreed, hit the diff lock or steering brake and you get the max traction available (force) from each wheel.

 

[Soundguy]

Alright.. I see you went the back door secret route and explained it in a way that most people are gonna miss it.. ( I did on 1st read) congratulations.. you must be a mechanical engineer. ( am I right? )

Carry on with the explanations that the average guys are gonna miss. If you ever need work I'm sure the government could use you to write manuals explaining tax code! Failing that, run for public office. being able to describe something nearly the opposite way it works ( but factually correct) is a GREAT skill for politicians.

If you want to say something.. say it.. Lots of us here are tech / engineering types.. but many are newbies passing thru looking for some quick info.. seeing your post.. they would have glossed over it just like i did on first read... and it wouldn't help them. and they'd be gone on their way with a screwed up understanding of physics..

This is about as good as 'how much work is being done' type of argument.. where no work is being done cuz the tractor ain't moving..

This isn't an attack message by the way.... just saying that we have all types from teens to seniors here.. everything from dirt farmers to rocket scientists.. if ya want to really get a message across.. use plainspeak.. For those that want to toss around the size of their frontal lobes. there are plenty of other forums for which to show off hi-brow conversational logic.

Have a good one. And yes.. you were correct about the 'force' being applied.. ( mechanical engineer right? )

soundguy

 

[xlr82v2]

Harry,

I got it the first time through... and TECHNICALLY, you were correct .

I don't get the super secret back door part though... because that's EXACTLY what happens... pretty front door to me.

Just ribbin' ya, Soundguy!

 

[Soundguy]

The 'force' argument is gonna fly right over the head of the average non engineer / techie type that is hopping in here to grab some quick answers and go.. that shouldn't be the purpose of this forum to obfuscate, but rather to clarify... sure he was correct.. but in such a way that a casual observer may be confused as to the explanation... there are plenty of forums for hi-brows to show off thier considerable intellegence and large hat sizes.. this forum should be for EZ to understand tractor info .. oops.. got to get off that soap box.. I almost got going again there!

soundguy

 

[geekfarmer]

As I have heard, the difference between 2WD and 4WD is about 50 ft. And once you get a $WD stuck, it is realy stuck.