Lower link settings
I wish I had my manual here, because I can't remember the technical name of these things. They are on the lower 3pt hitch arms of my JD 4300, and can be set to rigid or floating. They suggest floating for ground-engaging implements, and rigid for others.
I'm not sure I understand the whole point of this? Why not leave them floating all the time? And how do you define "ground-engaging"? Would this include, say, a dirt scoop, with which you just scoop up some dirt and then raise it and drive around with it in the air? Would it include a finish mower, which has wheels that ride on the ground constantly? The only implement of mine that I'm sure would be considered ground-engaging would be my tiller.
Any thoughts appreciated..
Re: Lower link settings
The adjustments you refer to are slots that allow the draft links to move up-and-down a small amount relative to the lift links. In addition, there is usually some provision for locking this "slop" out. The purpose is to allow the mounted implement a small amount of "roll" relative to the tractor. Sometimes in manuals and descriptions this is called "lateral float" but it is not an accurate term. Lateral implys left-to-right or side-to-side, but not a rotational motion as is the actual case.
One of the most important needs for the rotational degree-of-freedom is when attaching and detaching an implement. Unless both the tractor and implement are on a level slab of concrete or pavement, when the implement is parked on the ground the draft pins will normally not be quite level with the ends of the draft links when the tractor is backed up to make a connection. With float enabled on each lift link, you can manually raise each draft link slightly to ease the connecting process. Try this with the lift links locked to see how difficult this can be.
The roll degree-of-freedom also allows the implement to follow ground contours easily. This is especially important when the implement has its own gauge wheels or skids or is a blade or scoop. If you were to be using a rear utility blade and had the roll locked out to rigidize the hitch, then whenever the tractor wheels went up or down over bumps, it would try to force the blade to follow the same motions as the tractor resulting in a wavy cut.
The term "ground-engaging" usually means that some working surface (or surfaces), edge, or wheels touch the ground when the implement is in working position. Examples of non-ground engaging implements would be a ballast box and a sickle-bar mower.
As a practical matter you can leave the lift links in a float position almost all of the time. I never lock mine.
Some tractors do not have this float capability. An example would be the JD 4100.
Hope this helps.
Re: Lower link settings
Thanks very much.. the explained it perfectly for me. And yes, ever since I unlocked them, hooking up implements is much easier!