rotor-spin

I own a 1985 RX7-S in pretty good shape, except for the steering. I have tried to adjust it via recommended methods, but had some problems with the locknut for the sector endplay (slotted) screw loosening while driving, so I finally loctited it, and tightened it down pretty tight.

Normally, I'm not a hamfisted mechanic, (just an incredibly slow one) but when I loosened the nut some time afterward to tweak the adjustment, I noticed the adjusting screw was snapped in half.

Now, I have the cover off the steering box, and I'm wondering: is there any way to get the remaining part of the adjusting screw out of the top of the sector shaft, as it appears to be held captive under some kind of cap, (I thought I'd try to get a new adjuster made) or am I just S.O.L.? Thanks in advance for your suggestions!