4WD Problem

When I shift into 4WD there is a loud whining sound. When I shift back into 2WD it takes a moment and then there is a loud clunk like I just hit a pothole or something. I just checked the front differential fluid and filled it up til it started leaking out. Still have the problem ... any ideas?

Thanks

Welcome to Auto Forums GTKing :cheers:

From the sounds of it when you go into 4wd that whining sound is probably because your front axle isn't engaging.

That's my guess from experience. I've got a manual lock up system for the front diff, and I unlocked it at speed once without disengauging 4wd and that's the noise that it made.

Loud clunk I can't explain, but since you had to add fluid to the front diff look for a leak.

Here's a troubleshooting guide for the 4wd system
http://www.4x4posi-lok.com/PDFs/TSG_chevyT.pdf

I thought about my answer, and I was wrong.

I had disengaged my T-case without unlocking the front diff, so the drive shaft was still spinning when this noise occured.

So it's probably your transfer case not engaging, but your front differential is.

That trouble shooting guide that I gave you the link to should help you find the problem

Check out this thread:
http://www.automotiveforums.com/vbulletin/showthread.php?t=441178