I've had several Subarus and missed having one in my garage so I bought a 1983 Brat with a known automatic transmission issue, knowing I could get my hands on a 1981 wagon with a manual dual range 4WD transmission. The transmission issue is the usual one where it won't shift from first into a higher gear. I've never had a Subaru with an automatic transmission or power steering and so far I'm not impressed.
I'm not much of a mechanic but I am digging through the information on this awesome site trying to get the automatic transmission working. I have changed the ATF, swapped out the vacuum modulator (which was obviously bad) and inspected the governor gear (which looks good). I barely looked at the governor valve and haven't tried the other things indicated in the service manual like the control valve yet. This weekend I plan on dissembling and cleaning the governor valve, replacing the not so snug vacuum hose to the vacuum modulator, making sure there is vacuum to the vacuum modulator, make sure there is a diaphragm rod and O-ring behind the vacuum modulator, and maybe inspect the servo pipes. I will let you all know if I find anything interesting.
Honestly I'm hoping I can't fix the AT because I would much prefer to have a manual transmission in the Brat. My main reason for posting is to see if I could get confirmation that you can replace the AT on a 1983 Brat with the clutch and manual 4WD transmission from a 1981 wagon. A warm fuzzy if folks think a novice mechanic like myself can do it would also be nice.