This is a manual for the F4A33 & W4A33 from MMC(Mitsubishi Motors Corporation). It gives you lots of detailed information but there is some information the ATSG has this doesnt have. This is a PDF containing 148 pages.
90-91 1G AT Factory Service Manual Download: Click
90-91 1G AT Technical Service Manaul Download: Click
2G AT FSM Download: Click
Transmission Overhaul Manual Download: Click
This is the ATSG(Automatic Transmission Service Group) F4A33/W4A33 service and repair manual. This manual has some information the MMC manual doesnt and also has a little bit on transfer cases. This is a PDF containing 120 pages.
This one works well. https://mitsubishi.epc-data.com/
This is the Original parts lookup system mitsubishi used during the production of these cars. You can lookup cars by VIN, or by model and trim and look at illustrations and part numbers as well as cross reference parts with other cars. This REQUIRES 32 bit version of windows. If you have 64 bit then this will not work.
This is the current rendition of CAPS. Its called Mitsubishi ASA(Aftersales Support Application). This version likely has updated part numbers and information. It is recommended this be used over WinCAPS for its compatability, easier to use, and more information.
Download Japan Version: Click
North America version coming soon.
This is the presentation that Kiggly gave at the 2014 and 2015 shootout about the automatic transmissions.