When Your Tranny is in "Limp Mode". You have 3rd gear and reverse only. Usually an electrical problem.
It could be a several things (these are tough to diagnose): Transmission control unit is failing, Your shift solenoids attached to the Valve body (Inside the trans pan, See my shift kit web page) is bad or a wire is cut or disconnected and they (solenoids) are not receiving the signals.
I wont even go into possible stuck valves :eek: If it comes to that, plan on doing a shift kit.
First, check all of the wires goin to the tranny and look for cut or disconnected wires before digging into the tranny itself.
Now, You hit OD and nothing happens or revs high (4th gear no go). It is most likely the end clutches (see my page here:
http://www.plymouthlaser.com/ec.htm) This will show you why. The OEM plates bend and bind the clutch. Usually the end clutch is the first to go on the AT.
The other case is the end clutch tube is wrong in the valve body (usually after a rebuild). Once again, that is the shift kit fix.
Check the fluid level in Neutral (Car hot) after shifting this pattern: P-R-N-3-2-1-2-3-N . If it is off, add or remove. THese trannys are sensitive to fluid levels. I ONLY use Diamond ATF or B&M Trick Shift. The final thing, change the tranny filter as suggested. I do mine every 30K.
Charles
http://www.plymouthlaser.com