anyone know anything about '90 ranger auto transmission

[chargercalvin]

i know its not a charger but i knew if anyone could solve my problem it would be u guys. anyway, i got a 1990 ranger with a 2.9liter 6 and an automatic overdrive transmission. i tried to power break it and lay some sctatch in drive, but it just made a little click sound and went out of gear. it diddnt make a grinding noise or a pow sound, just a click, and now every gear is neutral eccapt park. it also makes a creaking sound when i shut the motor off. it isnt the rearend or the lnkage, and the trans fluid isnt burnt, so is it internal?, what should i do? i took it to a machanic and he doesnt know, is it something minor, or should i change the transmittion, also how much harder is it to switch it to strait drive. i know how much it will cost to change it, but how much to have a trans machanic examine it?

calvin