Any engine can have a catastrophic failure if neglected. The 3.7 and 4.7 are no different. There's millions of them still operating fine.

Personally the only failure I've seen frequently on these is the rocker arm problem, usually accompanied by sludge from lack of oil changes. So far I'm 3 for 3 on popping the arm back in.

Water pumps are straightforward. I'd recommend more frequent spark plug changes. Most common problem I see is rusty oil pans, but I'm in the salt Capitol of the world.

Regarding the transmission, the 3 I've owned were trouble free other than rusty pans and lines.