4WD wont engage????

[the boy]

I have a 2004 tahoe Z71 that i cant get the 4wd working, when you push the button you can hear the inside of the transfer case change, i replaced the thing on the front diff. when the truck is in 4wd now in park you cannot turn the front driveshaft by hand, but once you put the truck in gear its only in 2wd.......... anyone have any suggestion of what my problem is???????

[youngun]

sounds like you have a broken gear either in the front end or in transfer case. i had a bad transfer case before that was like that, couldn't turn it by hand but never pulled the front end when driving.

[the boy]

well when the truck is in 2wd you can turn the front shaft by hand, but when its in 4wd you cant, i just cant understand why its not working.....

[metalm0]

Could it be something with the cv's? Do you have the auto 4wd? If so then it shouldnt be a problem because the cv's are always engaged but the non auto 4wd my buds had some problems like that. Sometimes they would engage and sometimes they wouldnt.

[the boy]

yeah its got the auto 4wd.

[metalm0]

Have someone maybe watch to see if the front driveshaft is turning then. I mean its got to be something between the front diff and cv shafts then because if the front diff is moving and the cv's are always moving then something isnt engaging properly. Hmm...

[bluchevypick]

The front driveshaft and cv shafts always turn. If you have the autotrac transfer case, which is the nv246, it is prolly going into 4wd but your clutches in the transfer case are slipping and need to be replaced.

[GasGuzzler]

Info is hard to come by in this topic and there is no way to guess. There are a lot of suggestions but they're all throwing darts. Need to know more.

[txarkitekt]

Are you sure the Encoder motor is doing what it is suppose to?

[GasGuzzler]

Good question. He said something about the TC sounding like it was doing something...?