The pivot ball may have come out of its socket. I had the problem you are describing, and found out that the ball was missing. this makes the clutch fork not have anything to rest on, it requires more travel than the adjustments allow. feel around through the fork boot, see if you can find the pivot. it it's gone, most lkely that is what has been your problem. You may need to pull the tranny and glue another in place(pivot ball, not tranny...), or with enough finesse you may be able to replace it through the fork boot. good luck!
'81 CJ-7 Got it when I was 16!
'06 Hummer H3, boulder gray, Adventure Package(electric rear locker and 70:1 crawl ratio BONE STOCK)
'71 Kaiser-Jeep M35A2 Deuce and a Half cargo truck, with winch. <for sale>