Check your tranny fluid.
Possible broken or bent shift fork
check the reverse sensor. Open the hood and look on the passenger's side of the motor, where the transmission is. The sensor is all by itself, pretty mmuch in plain view, you'll see 2 wires coming out of it. If that little sensor is too tight, or doesnt have the right sized washer on it, you will not be able to put the car into reverse. Check that before you go spend a whole bunch of money on diagnosing / fixing other things.
If it is a manual transmission their is not one.
If it is a manual transmission, then it is on the front of the transmission. It is one of the two electical connectors on the transmission. The other is the vehicle speed sensor on the backside of the transmission.
haynes manual. You can get them at your local automotive store
Refer to your owner's manual for the right amount.
the 3000gt yes as long as both either manual or auto but cant interchange
There are several things that can cause your manual transmission not to shift out of first gear or reverse. The most common cause is a broken shifting fork.
It is not. The GS is a tranny for an I4, so its not quite wide enough to match up to the V6 block. And if I remember correctly, the 94 manual was a 6-speed. You'd need to get the tranny from a 3rd generation Eclipse GT (I know this works because I did it on my 97) but this only works if you have a SOHC motor, which Mitsubishi didn't put in the 3000GT until 97, but Dodge put it in the Stealth from the beginning. You're probably gonna have to hunt for a Stealth/3000GT parts car.
buy a new one you lost your shifting fork.
Yes sure you can. ___________________________________________________ I wouldn't recommend it, if you are referring to the automatic in an sl, because, with all due respect (I'm a huge Mitsubishi fan), they were quite inferior with an average lifespan of 75,000-100,000 if you're lucky. If that's what you're asking I would DEFINITELY recommend using the getrag manual gearbox that were offered for the 3000gt's.
In the owner's manual.
The transmission is a mitsubishi M05D-R2 5speed transmission. The fluid capacity is 4 quarts of ATF, most guys with shifting trouble have seen shifting improvement switching to Mobil-1.
Before there can be an answer, need to know transmission type; 6 speed manual or 6 speed automatic? If its the manual, its the clutch takeup cable. The shifter should have a button or detent to push in order to move it into Reverse. Its most likely loose. If its the automatic, its most likely the brake sensor that must be engaged prior to shifting from Park. Driver must fully engage the foot brake prior to shifting from Park to Reverse and from Drive to Reverse. Most likely replacement of part will fix issue.