Difference between 4WD and MFWD

[hayden]

OK, I'm confused. What's the difference between 4WD and MFWD? I though they were different names for the same thing, but in the Goodyear/Titan tire literature they make great distinction in tire recommendations between the two.

Anyone got the decoder ring?

[Woodbeef]

Well.............how big of tractors and tires are they talking about? A true 4wd is always in 4wd like big bend-in-the-middle tractors. A mfd tractor is selectable between rear wheel drive,and both axles engaged.

[jeffghs]

I'm guessing here too, but my thought is with MFWD the wheels turn at a different speed front to rear. With 4wd the front and rear are syncronized. Thats why a MFWD should not be run at speeds above 4mph.

[Steve02]

I'm just speculating here too, but I'm pretty sure the front tires don't spin any faster than the backs. That would be the quickest way to destroy your differential gears.

I always thought that a tractor with 4wd could be left in that mode long-term, whereas mfwd should only be used when needed.

[weesa20]

4wd technically is having all 4 tires the same size (therefore spinning at the same speed without fancy diffs that change saxle speed front to back). 4wd is typically found in 4wd trucks or most large articulating tractors.

MFWD is when the front and rear tires are different sizes and require diffs that change axle speeds, like in most of our "4wd" tractors which are actually MFWD.

That is the last thing I rember reading about this topic.

W

[jeffghs]

Originally Posted by Steve02

I'm just speculating here too, but I'm pretty sure the front tires don't spin any faster than the backs. That would be the quickest way to destroy your differential gears.

I always thought that a tractor with 4wd could be left in that mode long-term, whereas mfwd should only be used when needed.

My owner's manual actually has a warning to disengage the MFWD when operating on firm soil, level hard surfaces, or when roading the unit at highway speeds to maximize tire and driveline life and economize on fuel. That would tell me the front/rear operate at different speed.

[Soundguy]

Most compact tractors with 4wd or whatever we are calling it today, have from tires that 'lead' the rears... Thus the warning about using them on hard surfaces, and tire wear, and or scuffing.. etc..

Soundguy

[Farmwithjunk]

Originally Posted by hayden

OK, I'm confused. What's the difference between 4WD and MFWD? I though they were different names for the same thing, but in the Goodyear/Titan tire literature they make great distinction in tire recommendations between the two.

Anyone got the decoder ring?

This topic is sort of like the difference between a pond and a lake. We all know there's a difference. But at what point is the seperation marked?

From all I've read and heard, 4WD can operate in 4WD under all conditions. Front and rear are geared the same. (Over-all gearing, taking tire size in to consideration) They are generally designed and built specifically as 4WD tractors.

MFWD is an add on feature, USUALLY added to a tractor that's available in 2WD or MFWD variants. MOST MFWD tractors employ ever-so-slight higher (lower numeric) gearing in the front end to get the front end to "pull" the rear of the tractor through tough spots. They aren't intended to leave front axle in gear constantly, but as needed.

From the wording used in some tire marketing, as well as tractor adds, the difference is more abstract than the well defined explaination we would all like to hear.

[Fishguy]

Originally Posted by Farmwithjunk

This topic is sort of like the difference between a pond and a lake. We all know there's a difference. But at what point is the seperation marked?

Kinda goes along with when does a nail become a spike? Webster's says a spike is a "heavy nail"???

Steve

[Tractor Tom]

When my Kioti dealer delivered my CK20 he mentioned that when in 4WD the front axle actually turns about 3 to 5% faster than the rear axle. The reason is for this is turning; with a faster front axle it can better lead the rest of the tractor around a turn by getting a more aggressive bite on the ground. This makes your tractor track better as opposed to “pushing” wide in a turn. I was also told to take it out of 4WD when on hard pack or when in high range.