My favorite wrench at AAMCO is a T4R enthusiast. He told me these T4R autos are considered "million mile trannies" and that the same tranny used in my 87 22RE is used in the new V-8's. Whether that last is true, I don't know.
About a month later, my auto tranny had a catastrophic failure. Unfortunately, my favorite AAMCO wrench had been transferred in the interim. His successor was quoting me $6000 to repair, $6500 to replace the thing. I went for a manual conversion instead.
History wise, my T4R ate its first auto tranny at 78K miles. Since this was about a month after I bought the truck, I cannot know if it was a bum tranny or a bum PO. Luckily I had purchased the extended warranty, so my $4500 repair bill only cost me $50, plus I think the warranty itself was only about $800. Cha-Ching!
The situation described at the beginning of my post happened at 198K miles. I am fairly good about maintaining my tranny, I get it checked every 3000 miles along with an oil change, etc.
For your Africa rally, I'd definitely opt for the manual. You're looking at about a 300lb weight differential, plus an auto T4R (at least in first gens w/22RE) comes with a weaker chain driven transfer case. On top of that, you've got the greater power loss through the drivetrain. Plus, that African heat can't be too good for a juicebox.
Going for convenience in LA traffic is one thing, getting into dire circumstances in the middle of Africa due to a lunched auto tranny is another thing altogether. If you really want to scare yourself, see if your local dealer has a auto flexplate lying around. You'd be surprised how thin that vital piece is.
Plus, thinking about spare parts in Africa, manual would be better. If you decide to go with an auto, make sure you put a stout tranny cooler on it before you put the truck on the ship for Africa.
