Well, that's what it is called in the parts book. It is a little piece of steel that keeps the three shift rods in place while the shift forks slide on them forward and aft on commands from the gear shift lever (stick). If the rods are not stationary in the trans case cover, the ball and springs in the forks may not give you the feel of the detents in the rods, and shifts might get (more) awkward. Fortunately, when the retainer breaks, it only effects reverse gear. If you don't feel a detent when shifting in and out of reverse, or you can see the far right rod move fore and aft, yours might be broken.
So with a swift kick from mmcinnis, these reproductions were made. Easy off, easy on when sitting on a bench like this, not so bad on a clean, assembled trans-tcase. If you are working on an encrusted assembly you may have to remove the tcase top cover to get a socket on the bolts. Wiggle the stick shift to line up the rods as you slide the retainer up and into their grooves.
You may note that there is a little overhang of the retainer just below the reverse rod. This is exactly how my original rests, I never noticed it before, and it bugs me. I think it may pre-stress an already bad design when the cover and case of the trans to not match up exactly, gasket material, dirt, etc get between the retainer and cover. So I ground down that portion of the retainer that rests in the reverse rod groove to eliminate the overhang. As a side note, the retainer is forced to the rear when the stick is moved from R to N and I can see the retainer flex just a little bit.
So with a swift kick from mmcinnis, these reproductions were made. Easy off, easy on when sitting on a bench like this, not so bad on a clean, assembled trans-tcase. If you are working on an encrusted assembly you may have to remove the tcase top cover to get a socket on the bolts. Wiggle the stick shift to line up the rods as you slide the retainer up and into their grooves.
You may note that there is a little overhang of the retainer just below the reverse rod. This is exactly how my original rests, I never noticed it before, and it bugs me. I think it may pre-stress an already bad design when the cover and case of the trans to not match up exactly, gasket material, dirt, etc get between the retainer and cover. So I ground down that portion of the retainer that rests in the reverse rod groove to eliminate the overhang. As a side note, the retainer is forced to the rear when the stick is moved from R to N and I can see the retainer flex just a little bit.