Need help with rattle noise from 99 Tahoe transfer case

[gold67rs]

Hello fellow forum users I just joined but I am having a problem with my Tahoe. I have a 1999 Chevy Tahoe with about 89K miles that has a rattle coming from the transfer case. This rattle seems to be there all the time, in park, stopped in drive, and while driving. I live in the mountains of NM and use the auto 4x4 and 4h on occasions and they seem to operate well. It is a very noticeable noise. At the same time I am also experiencing a vibration that is transmitted through the accelerator petal that happens mainly at 1000 to 1200 rpm while driving only (unable to reproduce when in park). I do not know if these two problems are related or not. The truck is well cared for and fluids are changed regularly. Please help. gold67rs

[777stickman]

Hard to think the t-case is making the noise when it's not turning as in park or stopped. I'd be more inclined to think the tranny or torque converter.

Have you had up on a rack to pinpoint where the noise is coming from?

[gold67rs]

I had it up on jack stands and crawled around under the truck until I located the noise coming from the rear of the transfer case and tale section of the transmission.

[wafrederick]

Did you put in the right fluid in the transfercase?Use only Auto Trak II fluid from the dealer only.It does not use atf and this started in 1999