ATF+3 had a very-short service life due to breakdown. Though your owner's manual may have said that in normal usage it never needed to be changed, it's well known that at 30,000 miles it needed to be changed. Torque converter shudder was the first sign. ATF+4 was developed to replace ATF+3 as a 100,000-mile fluid, hence the reasoning behind synthetic (Group III) base oils as well as a new Lubrizol additive package. ATF+4 was mandated to be backward compatible since Chrysler did not want to come up with another new friction material like they did when they switched to ATF+3. That last bit is very important. While Chrysler found that the ATF+3 was backward-compatible for the older transmissions, it was not specifically formulated for the friction materials used in those transmissions. In other words, it worked but it wasn't optimal (turned out it wasn't optimal for the transmissions for which it was developed, either). If it's an original transmission, not rebuilt, I'd recommend the Type F/FA. If it's been gone through, then it depends on which manufacturer made your friction materials and what they recommend, I suppose... but if I owned anything with a classic A-series automatic, personally I'd still run Type F/FA. It's what's worked for me for nearly 30 years in the older transmissions. Others may have different experiences and mine's no better than theirs.
I think the vast majority of transmission issues can be traced to people being lazy, be it the owner or the guy servicing it. At the diesel shop, guys would continually bitch about the 47RE/48RE being "junk" transmissions, so I asked every one that did, "How often did you change the fluid and have the bands adjusted?" I'd get a slack jaw and a blank stare in response every damned time. Holy mackerel, you have to service these things?! I thought you just put them in gear and ran them forever!
I think the vast majority of transmission issues can be traced to people being lazy, be it the owner or the guy servicing it. At the diesel shop, guys would continually bitch about the 47RE/48RE being "junk" transmissions, so I asked every one that did, "How often did you change the fluid and have the bands adjusted?" I'd get a slack jaw and a blank stare in response every damned time. Holy mackerel, you have to service these things?! I thought you just put them in gear and ran them forever!
