<p>Does anyone have any ideas about this problem? The transmission worked properly with no sign about any problem - just progressively got harder to shift into a position. Now locked in drive - always had plenty of the proper transmission fluid.</p>

What model/year? It might just be the shifter assembly.

Hi, thanks for your fast response. Its a1990 Subaru Loyal Wagon four wheel drive with the three speed automatic transmission. I checked all the shifter assembly inside the car and all works properly - with the single shifting rod disconnected from the transmission side. The shifting lever on the transmission is locked in the drive position and this position is confirmed as such by the Haynes repair manual. Even with an extension applied to the lever it wont move. The battery is removed so maybe some solenoid inside the transmission has it locked? Nothing appears to be rubbing on the linkage inside or outside. This problem first appeared during very cold weather 0-15 degrees F, and the car could not be driven. Warmer weather has not fixed the problem. It might have been overfilled with oil, but, draining the oil had no effect! Thanks again and any ideas would be welcome