I had a 2003, the last year of the body on frame Durango. It was a 4.7L SLT plus that came with all of the options except moon roof.
It went 190,000 miles before any major repairs (water pump, plugs, oil and routine maintenance not included). At 190K, front drive shaft CV joint failed. Out of balance condition ovaled the front transfer case bearing mount. Repaired that and ran it for another 30K when I donated it to a local charity after getting my 2014 Ram. In that 220,000 miles, neither the engine or the transmission were ever opened up for any reason.
It was AWD and still the best snow vehicle I have ever driven.
Faults: AWD keeps the MPG down: 15.5 MPG average for city and highway without much variation between the two.
Around here, there are lots of pre 2004 Durangos still on the road.
The 2004s came out with the 5.7L Hemi and unibody construction. 2014 introduced the 8 speen transmission.