Shifting Problem

Hey....again I need a little help in diagnosing and fixing a problem with my 89....
Basically, I was out driving and the car wouldn't go in to 2nd gear....I'd try to shift from 1st or downshift from 3rd, but it felt like the shift linkage was being blocked....I could get the shaft to engage a little, and it would occasionally hook up, but then it would spit the shaft out of gear.....After working the shifter around a little I can occasionally get it to drop into 2nd properly, but it's started to do this with 4th as well. All the upper gears, 1st, 3rd, and 5th, and Reverse shift with no problem. The problem started suddenly, and progressed from just a problem with 2nd to 2nd and 4th within about 5 min.
Help would be greatly appreciated
Thanks

sounds like a 1-2 shift fork to me. as far as 4th being a problem im not so sure as ive never encountered that b4. but to be safe double check your front and rear motor mounts.

Thanks....forgive my ignroance though....how hard is it to replace the fork, if It's even possible....or can I do something to fix it? Is it a good idea to go to the wreckers for the part or should I source it new only?
Again...help appreciated....