Need help identifying this part : pic inside

I have major "play " in the steering on my 92xj .

Here is a picture of damage that I can see . The arrow points to a part that has missing/damaged/stipped teeth .

What is this part called ? Should that much of the gear be showing ??
and can I replace just that part or do I need a whole new steering box . ?

When the truck is "cold" it has about 3-4inches of play at the steering wheel , as it warms up to operating temp , the play goes away some . but it is still pretty sloppy .

Thank you .

replace the whole box and while your at it go ahead and upgrade to the durango box. i dont know if they sell a rebuld kit for the box and if the do it wont come with that part. thats a non wear item.

That's the "pitman shaft" of the steering gear, and the thing bolted to it is the pitman arm. It is a tapered fit on splines, and should not be loose, but you need to look closer at it to determine if it really is. It should never, ever, not ever, never never (please note my subtle attempt to convey urgency) slip or be loose! It normally will take a hefty puller to get it off. If it is actually slipping or loose you should not take your Jeep one foot further before fixing it unless you are fixing to die. edit to add: if it has been running loose, I would suggest replacing both box and arm for safety if there is any trace of wear.

The splines in the pitman shaft are designed with a wide spline that looks flat, so that you can put the arm on in only one orientation, and that may be what is appearing to you like a stripped spline.

If it is not loose, you need to find where else the play is developing. A common area is in the pitman shaft bearing, which when it wears allows side play, which might on cursory examination look like a loose arm. That's annoying but will not kill you as a loose pitman arm will. If you have play in the bearing and also in the steering gear, your best option is probably a new or rebuilt box.