4x4 Driveline Question

the locking hubs would be the first place for damage to occur.

4 miles in 4high is prolly not enough to hurt anything...

Yeh, I do that all the time and I do it for several hours at a time and I havent had any problems. I was told to free up the hubs (I think they are called Warn hubs) every so often by locking them and then unlocking them while in N or P. I like 4wd as compared to AWD (no hubs to turn). Dont know why, but the assemblies are all seemeingly made from metal cast in China and theyre metallurgy is really third world, no matter what anyone says.

I do recall a warning from years aago that running the vehicle in low range with hubs unlocked could break something due to excessive torque. Still not sure what parts would break though.

low range is a whole 'nother ball of wax.

transfer case comes into play.

Wouldn´t high range 4 wheel drive involve the transfer case as well? How else is drive sent to both front and rear axles?

high range does engage the case, but does not involve the inner workings that change the ratios.