95 Tranny Problems

[hyper31]

I have a 95 T-Bird with the 4.6 auto tranny. It doesn't shift. I can put in reverse, neutral, Drive, 1, and 2. all of that works, it just doesn't shift automatically. If I have it in drive and rev to over 4000 r's then let off, it will shift into second but won't go any farther then that. Also it will not shift back into 1st unless I come to a complete stop. Any ideas on what is going on? I really don't want to stick a ton of money into it. Thanks in advance.

Joe

[Blue)(Fusion]

I'd start by looking into the condition of the ATF and proper operation of, or replacing (even as a preventative maintenance measure) the MLPS (driver side of transmission body) and the TPS (on the throttle body). The PCM uses data from these to determine shifts.

If the ATF is discolored and smells burnt, it needs to be flushed with fresh Mercon V ATF.

If the ATF is in good condition and the sensors are working properly, than it is probably the shift solenoids. They are pretty easily replaced once you remove the transmission pan.