I have a 1989 chevy tracker, the shift cable has been replaced now has one missing bolt to keep it in, car shifted gears no problems then the clutch had to be put to the floor to shift, then could not shift at all, replaced a bearing or something like that in the tranny because when the clutch was pushed it stuck and would not slide back, it still did not work so we replaced the clutch pedal and bracket, it worked like a charm for two days now it is back to going to the floor and will not shift into any gears at all, and trying to put it in reverse it grinds and will not go into gear. what else could be wrong.

SOURCE: tdi clutch pedal pushed all the way down but hard to shift gears

Check your clutch fluid level, sometimes a seperate reservoir (drivers side on firewall), some clutch systems take fluid from the brake system (check brake fluid). If thats ok then the clutch slave may be failing.
If the clutch fluid is low refill it and check for leaks (or just wait till the symptom comes back). If it's happens often then theres a leak in the line or the slave somewhere.

SOURCE: My car won't go in gear

I got same problem when I first got the car (bought used), took me a day to find out one of the fuse blown caused the problem now I always have 10A fuse spare in my glove comparment, check all your fuses (I believe it's an Audio/Clock 10A fuse) will solve your, good luck ...

SOURCE: Need to replace throw out bearing on a 1989 4x4 tracker

no, the throwout bearing is behind the clutch. you will have to remove the tranny.

SOURCE: gear shift "loose" - car won't go into any gear

it could be your shift cable snapped?

SOURCE: Mazda 626 - Hard to shift into gear.

With any vehicle that has a hydraulic clutch, a worn master cylinder or slave cylinder will give this very symptom. First step is to check the fluid in the resivor. If it is low, you will want to check for fluid bypassing the seals. Be sure to check under the rubber dust cover as fluid can collect there and not be readily visible. Also, if the fluid in the resivor is dark colored, it is an indication of the internal seals going bad and you will need to replace the cylinders.