i initially thought that the AOD would be better as far as gas mileage but was told that the aod would not be very reliable. i was told that the c4 is a far more reliable trans. what are your opinions and experiences?
Either one with minimal mods will hold up to 400hp. Even more with out breaking the bank. The key is to rebuild it yourself. Get a transmission manual and read at clickclickracing.com for AOD and fordmuscle.com for C4, they have a C4 section. It is not rocket science.
very early AOD's did have a bad reputation for breaking, especially behind a modified engine, but those problems have long since been resolved. AOD's built after 1985 are solid reliable units that as stated with a little work can handle better than 400hp easily. and the after market is loaded with AOD parts to make the trans even better. understand that the AOD is based on the FMX architecture which was also a solid ans reliable trans. but both transmissions are heavy compared to the C4. if you are building a street or street/strip car, go with the AOD and get a lentech valve body that changes the shift pattern so you dont have to do the 1-3-1 dance to hold second gear. also make sure you get the throttle valve cable adjustment right otherwise you will burn up a good AOD.
Are we talking about the Z-F, 4-speed AOD? If so it is the very same transmission that came in 'S' class M-B, 6-7 series BMW and all big Ford cars. I know of at least a dozen of these units in big M-B's (380 lbft and 5000 lb vehicle weight) that have well over 400,000 miles with ZERO problems...of course M-B says you should change fluid every 2 years or 25,000 miles and Ford says you should NEVER need to service the same transmission but then again the Ford unit is good for only about 125,000 miles.
I think you'll be good to go with the AOD...plus you get a shorter 1st and something like 30% o.d.
I always say when you can upgrade do it so i'd lean toward the AOD. 15 years ago I rebuilt my C-4 and was shocked at how easy it was and was not quite the mechanic I am today.