expected lifespan of a rear differential?

[MSCH]

I'm pretty sure it's still just a standard 11.5" AAM but they did add an anti swaybar or something.

I'm not 100% on this, but somewhere in the mid teens Mopar started using a 11.8 in the AAM and it might be standard now, but there was a point where the HO duallies did get an 18 bolt ring gear. I was looking into repairing one of these, so I did run into some confusion as there seem to be changes and such https://www.demandaam.com/technical-support/dodge-part-diagrams

and this is the 16 or 18 bolt which might not be used anymore https://www.ronsmachiningservice.ne...0-aam-11-8-4-10-ring-and-pinion-aam-gear-set/

 

[The motor guy]

11.5 is the ring gear size

 

[MSCH]

11.5 is the ring gear size

depends on year and application... it appears on 3500's from 2014 its an 11.8, the 11.5 sounds like what the 2500's receive from 2003 to current... see parts diagram https://www.demandaam.com/technical-support/dodge-part-diagrams