I tried to put my 2011 Chevy Blazer in 4WD while in drive. When I realized my mistake I put it in Neutral, but then I couldn't put it in reverse. Did I do long-term damage?

 

I assume you mean 2001.

The transfer cases used in the s-series trucks are all shift on the fly capable meaning that you can shift from 2HI to 4HI while driving. It does make the transition a lot easier when the truck is coasting and/or at relatively low speeds, but it is not necessary to stop or have the transmission in neutral to make the shift.


What happened when you tried to put it into 4wd? I cannot see any reason why a shift to 4HI would cause the truck to not go into reverse. Please detail your situation more thoroughly and we'll try to help as best we can.