Some Confusion About front wheel Assist 7 4WD

I have seen some post on this forum about using their tractors with front wheel assist and I am wondering what they are referring to.
In my experience, front wheel assist refers to those front wheel drives that are actually driven by a hydraulic motor. John Deere did offer tractors with front wheel assist that used hydraulic motors, one on each front wheel, to provide some power to the front wheels. I have also seen the same setup on some other tractor brands, including Allis Chalmers.
While this system did offer some help in slippery going they are limited by the size of the hydraulic pump and the hydraulic drive motors.

Four wheel drive tractors are more commonly called MFWD or mechanical front wheel drive and these are driven by a drive shaft that is in sync with the rear drive. The front wheels , when activated, will turn whenever the rear wheels do. They have a fair amount of pulling power and are a great help in slippery going as in mud and snow.

AWD, all wheel drive, is another term often used to describe tractors with front wheels that are powered but I was led to believe that this term was for those tractors where the front and rear wheels were powered at all time. These are the tractors with the same sized tires on the front as on the rear. Many of the articulated tractors are AWD.

In truth, I guess, all tractors with power to the front wheels could be called, front wheel assisted.

Another term for the hydraulic driven wheels is Mud Hog. These Mud Hog drives are widely used on the rear wheels of combines that have hydro drives.
Again, they do help in slippery going but they often will stop turning.

Call it what you want to I guess. HFWA or HWFD,hydraulic front wheel assist or hydraulic front wheel drive. MFWA,MFWD,mechanical. So few of the hydraulic units anymore that FWA just seems to mean mechanical front wheel assist as opposed to a true 4 wheel drive where all 4 wheels are the same size.

To further complicate the matter some MFWD systems are actually only 3 wheel drive in that there is no differential lock on the front axle. I have had both an automatic diff lock and a hydraulically activated diff locking front axle....I think I liked the auto one better for working on grass. The hydraulic activated type only works on the straight line and has to be released before turning. Virtually all tractors sold in the UK since the mid 80s are MFWD.....Farmers here believe you have only half a tractor without it...In fact young tractor drivers have never driven anything else and are completely lost on 2WD machines!...

Sam

When you get out to big farm country, 4wd means 4 wheels all the same size. No AWDs here. Mud Hog is a brand name of aftermarket hydraulic drives.