my 1990 4runner will shift through all the gears when it is turned off but when i turn it on i can't put it in any gear. the clutch feels a little mushy too. does that mean i need to replace it? how do i check my clutch fluid? ...guess i dumped the last bf a little too soon... :p

You are apparently not able to disengage your clutch. This is most likely due to air in the line - low fluid. For this fill the clutch master cylinder reservoir (next to the brake master cylinder) and bleed the line like a brake line. A Haynes or Chiltons manual will help.

Might also mean that a part of the clutch release mechanism is bent or broken.