Automatics generally last 250k miles, average, so some fail earlier some last longer
The clutches and bands wear out, friction material, same as clutch wears out on manual trans or brake pads/shoes wear out
Without service other stuff breaks
People like "horror stories" about Automatics, not sure why?
Most likely has to do more with transmission shops than transmission design
Ford used the same OverDrive automatic in Rangers from 1985 thru 2011, 26 years, so it is a good design
Trans shop can do a minimum rebuild, clutches and bands only, and trans will last another 12 to 18months
Good rebuild will last another 200+k miles, same as new
There are some poorly designed automatics, but Rangers didn't use those
Manual transmission is about the same as an engine as far as diagnosis and repairs
Automatics are WAY more complicated to diagnose, because they have many interdependent systems
So people can get frustrated if there is a problem and no one can tell them EXACTLY what part has failed, best guess is all you can hope for until transmission has been torn apart
When the transmission in my Bronco 2 was rebuilt by AAMCO, they really couldn't tell me much without a complete teardown, makes sense given there's no way to really tell what's broke and/or worn out without a visual inspection...however the A4LD's are pretty failure prone due to abuse and neglect, which is why so many of us don't recommend them, no matter who does the rebuild, they just extend a ticking time bomb because of poor rebuild shops. Even with auxiliary coolers, and "beefed up" components they're still the weak link...same goes for clutches, if you abuse them, they are the weak link.
The "A4LD" got renamed so many times as they tried to re-engineer them into different transmissions, but they seemed to have kept making them under different names and adding gears per-se...the newer ones tended to have less issues it seemed as time went on and they found the problems and fixed them, but it seemed like the early 80's to mid 80's were the biggest problems....a good transmission shop will do the rebuilds on them properly and they'll last, its one of those you get what you pay for type things. A no-name shop typically only replaces friction plates and discs and bands, and leaves the rest of the problems in the transmission to just wear out the same components over and over...a valve body has a lot of places for failures too and all those tiny little passages in them make for great places for debris to get stuck in and cause all sorts of problems, and will take out a transmission in short order.
One huge problem is people tend to skip routine maintenance and by the time the 3rd or 4th owner gets them they're all clapped out...so our response is well that pile of crap automatic transmission is the problem every single time, so the transmission itself gets the bad reputation, rather than blaming the right thing, the previous owner(s) and their complete neglect of simple maintenance.
My 93 Ranger had a bad transmission when I got it, the shop that rebuilt it did a terrible job, 13 months later it blew up again...sold the truck for $700 and let someone else deal with that problem LOL. My Bronco 2 got me 30 miles home after I bought it but had no overdrive. AAMCO did the rebuild and replaced practically everything it seemed, that got expensive real quick. AAMCO gets bad reviews too, but I think some of that boils down to the customers wanting to take the cheap way out on everything, rather than just doing it right, it'll cost a bit more, but it'll still be working for years rather than months LOL. Luckily my AAMCO had a retired Ford tech working for them and did the rebuild....he's seen a few of the A4LD's over the years LOL.
If you buy used, which is the only way you are gonna run across one of the A4LD variants now, if they can't provide any documentation of regular transmission service I'd avoid it. A transmission drain, filter replacement, and new fluid every couple years is a heck of a lot cheaper than a transmission or a rebuild, which we all know if you keep a vehicle long enough you are gonna be having it rebuilt anyways, but to keep it going as long as possible keep up with maintenance.
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