I have lost 1st and 2nd gears in my 1991 f150 4x4, still has 3rd, 4th, 5th, and R. I searched the forums and several of the threads indicated that the shifter fork could be broken, bent or cracked and to take the top of off the transmission. I have never been into a transmission, is this very difficult to accomplish or a fairly simple check.

 

M5OD Mazda Design Manual Five Speed Transmission Preventative Measure .: Articles Good instructions in this article about getting the top off (assuming you have the Mazda trans).