N..., and an automatic transmission is one of the few parts of a car that I can't fix myself. Most professional mechanics won't even touch them. A manual, on the other hand, is delightfully simple.
Surprisingly many aren’t that bad to rebuild. The issues usually are around needing a very beefy bench, GOOD organization skills, and a big press for most of them for the bearings. Especially older designs without way too much computer involvement just aren’t that difficult.
But... it also takes a lot of TIME and that’s why most mechanics avoid it. Book time is hard to beat on them and that’s why the trans guys just charge a flat price that’s fairly high.
Moving the bastards around is one of the biggest problems. That and a handful of specialized tools.
I don’t want to tackle it myself, but occasionally it’s fun to pull up a YT video of anyone doing it who does it for a living. Methodical and organized and always a few little tips and tricks that would help anyone doing the type of trans they’re working on. Usually the trick to getting the wiring harnesses unplugged and pulling sensors out without damaging them.
Ordering the right rebuild kit is also crucial and those guys know the part numbers by heart. They always have extra ball bearings for the valve bodies and such lying around when they drop one and it rolls into never never land somewhere too. That one can bring a small shop or home gamer to a halt for two days. Ha.
All sorts of carburetors are a lot harder and more fiddly to rebuild than many of the popular transmissions. And I’ve done those. But those are going away for small engines, they just sell you a whole new one that isn’t adjustable because it meets California emissions standards.
And therefore runs like crap at my altitude. LOL.
And not too many big engines using them anymore either.
Dropping carb parts on the floor is worse than dropping transmission valve balls though. Ha.
Ahhhhh. Never mind. Both suck really.
Stacking plates and frictions in an auto is pretty easy.
There were some manuals I’ve watched rebuilt that I wouldn’t want anything to do with though. Weird ass assembly order and gear location if you didn’t have pictures.
Lots of time and parts cleaning and patience.
The other thing the experienced rebuilders have is eyeballing which parts are out of spec and worn even if they’re not supposed to be. Adds a lot of time if you have to look it up and use the calipers on a bunch of stuff.