Toyota Repair: Corolla automatic transmissions, toyota corolla dx, coolant lines

Question
1992 Toyota Corolla dx. model with 131l automatic transmission with 192K miles has no reverse after I started it up without hooking up the trans. coolant lines to the radiator. This drained all the oil out. Replaced the oil and still no reverse.  After taking it apart, we found the tranny oil dirty and having some brass chips in filter and gritty oil, and appeared that the oil had not been changed in a long time. Replacing the filter and oil, but not dropping the valve body, reassembled it only to find that there still was no reverse.  In reverse, It seems to be in both first gear and reverse at the same time, as if locked up as in park and the nuetral is allways in low gear also. However, the rest of the transmission forward drive gears..first thru third and overdrive operate great shifing up and down shifting. .....I now have the valve body body off but don't wish to go any further without more information.  I am not an expert.  Could you help me to say weather I can do a "quick" check in the valve body. ..Another strange thing I discovered was that the main spider drive gear had several flat spots on the teeth "I thought very unusual".  Could you help me out?  

Answer
The transmission has a major problem, it looks like the clutches are starting to come apart and any metal particles in the pan are also not good, I would recommend that you either get a remanufactured trans or try to find a good low mileage used unit, transmission parts are very expensive and overhauling or repairing is time consuming.