What happens if your truck is in 4 wheel drive and you drive it on a highway?
If you make a lot of sharp turns you can damage the drive train. Have you noticed binding and hopping when making turns?
You can damage the transfer case and the front differential if driven to long cause the front differential is geared slighter faster the rear so you get sort of a pulling effect off road. On hard surface there is more traction so the tires can't slip as much. Had a customer that ran his in 4X4 all the time cause he was on and off road a lot but even then he still roasted the transfer case