my 89 subaru dl hatchback won't go into gear

was slipping a little bit. the car was sitting for a while when i bought it. so my dad drained all the fluid because it looked old. now the car won't go into gear at all. he drained 4 qts of tranny fluid and only put 3 back in and now it won't go into gear. if anyone could help me then that would be great.

Well first if the fluid isn't filled completely it should be. On high-mileage automatics that haven't had the fluid changed in a long time, it is sometimes a bad idea to do so. The fresh fluid can flush out the "false seals" that have built up with the old dirty fluid, and this can result in a loss of internal pressure and failure of the transmission. If this is what happened the fix, unfortunately, will be a rebuild or replacement.

If this is a manual transmission it is important that the gear oil be the correct viscosity.