[denisond3]

I havent opened up my Saturn SL2 trans to see (it was refusing to go into 2nd without extreme pressure on the shift lever), if its a two fork or three fork setup. But the shift mechanism going into the trans does two things. One is to select whether you will be moving the forks for 1-2, or 3-4, or 5-reverse gears. Thats the job of the upper shift cable on the trans; and it is moved when you move the shift lever 'left-right'. The other cable moves the shifting fork (or forks) that give you either 1, 3, or 5; or give you 2, 4, & reverse; which happens when you move the shift lever 'fore-aft'.. Based on your description, I could imagine the mechanism to the upper cable is bent, or that something lying inside the bottom of the transmission has gotten in the way. The bad news in that case is that trans removal and disassembly is the only way to fix that.
However, I agree with the prior poster. A very likely failure could be that the spring clip holding the outer cover of the upper shift cable into its groove on the trans housing has come apart, and the end of the cable has moved half an inch 'out' of its 'socket'. If someone ever took that clips out, they arent the easiest thing to re-install. especially with all of the plumbing/wiring that is in the way.
I wouldnt think the shift cable could be faulty - since I think the usual failure (by corrosion) of a shift cable would mean you wouldnt be able to move the shift lever around without extreme force.

I got a JY trans for mine, and installed those shift cables and their retaining clips while the engine was almost-but-not-quite lowered into position. Easier, but it still was a slow job. Luckily new spring clips came with the new shift cables I bought. The old ones fell apart coming out.