Should front driveshaft be turning while in 2WD?

.....mine does. If it IS supposed to be turning, why do I need an automatic transfer case? If it shouldn't be turning, what needs to be fixed?

Here are the details. I have a '00 Z71 that has the pushbutton 4HI, 4LO, and Autotrac. I recently had to have some work done on the truck. The mechanic had to disconnect the front end of the front driveshaft to reach something. The truck was on a lift in the shop. Before he disconnected the front driveshaft, he tried to turn it...it wouldn't. After disconnecting the front driveshaft at the front end, he was able to turn the yoke at the front differential...meaning the front differential was NOT engaged.

He was curious, so after finishing his work, he started the truck on the lift. In 2WD, the front shaft WAS spinning at a rate close to the back shaft. If this is supposed to be normal, as some old posts suggest, what is the transfer case for?

yip this is normal i too have a 00 z-71 and the front shaft will turn all the time it's the diff that's not engaged untill you select 4x4,an electronic solinoid will engage when you select 4x4 you can hear it with the truck off push the button and listen to it engage into the front diff, the transfer case is to redirect the turning motion the opisite way toward's the front and change the speed it turn's i.e low or hi. p.s the stock u-joint's are crap you cant grease them and they will make a winning noise as they head out hte door, be sure to change them with greasable u-joints' and a good quality one

It is normal for the driveshaft to turn on vehicles equipped with the auto-trac transfer case.

do you mean ss trucks? all wheel drive or z-71 4x4 with auto 4x4? mine has auto,4 hi and 4 lo and it turn's always this is how i found out the u-joint's were winning, i too thought that the back only turned untill i looked while on jack stand's to find the noise, put it in drive and vollahh!

yip this is normal i too have a 00 z-71 and the front shaft will turn all the time it's the diff that's not engaged untill you select 4x4,an electronic solinoid will engage when you select 4x4 you can hear it with the truck off push the button and listen to it engage into the front diff, the transfer case is to redirect the turning motion the opisite way toward's the front and change the speed it turn's i.e low or hi. p.s the stock u-joint's are crap you cant grease them and they will make a winning noise as they head out hte door, be sure to change them with greasable u-joints' and a good quality one

Do you mean the constant velocity joints or the universal joints? My front axles have CV joints and they are unserviceable which sucks because my left side rotor overheated and melted the packed grease out of the outboard CV joint. They cost like $300 ea.

no no ,drive shaft u-joint's!