I would think married transfer cases would be stronger, but Internet People seem to indicate otherwise. What’s up with that?
That is confusing, isn’t it? I think some of that lore has to do with two other aspects of the case. Given that divorced cases from way back when didn’t have the stiffening aspect of being bolted to a larger unit (the trans), they were often made from cast iron due to the metallurgy of the day.
Today, that means cast iron T-cases may be seen as a little tougher in an offroad scenario because rock strikes and debris impact that would window an aluminum unit might have no apparent effect on the iron case. Aluminum is of course lighter and also dissipates heat a bit better.
The second aspect is the bits inside. Most modern, married t-cases are driven by sprockets and chains since noise and weight are greater considerations today than they were many moons ago. Way back when, some t-cases were driven gear-to-gear. Those babies are often tolerant of abuse.
In any case (I’ll show myself the door, thank you), there are certainly very rugged examples of each design.
Andy mentioned custom 4WD rigs; why exactly do they want divorced units?
Well, two reasons. One is flexibility. Off road, short wheelbases and high ground clearance can make for a more useful trail truck. But those very same characteristics can make for some really weird driveshaft angles and can make for shafts that wind up hanging too low.