Rons 5.3

iTrader: (7)

I have a loud noise coming from under the truck, I notice it when putting the truck in gear. Not a clunk from say the u-joints but more of a metallic *tink* sound.
Under acceleration it makes more of a rotational *tink tink tink* noise in first and under light throttle in second gear. Gets faster as I accelerate.I am wondering first of all if the front driveshaft turns when in 2hi and if this could possibly be a loose chain or broken gear in the transfer case.
This has been going on for over a week. I have no knowledge of how the auto-trac works, but was thinking if the chain in the transfer case was worn and loose the noise could be the chain skipping (if it even turns while in 2hi).
Sorry for the long post, but I am hoping for some good info so I can fix this. I have another thread going in General Discussion, but hoping to get more over here. Thanks, Ron

KySilverado

iTrader: (7)

Little bit confused. You mention being in 2 hi but your sig says an SS and your name is Ron 5.3. An SS is AWD and don't come with 5.3's?

Doesn't look like power is applied to the front unless in 4wd. You can see the shift fork that locks the front output shaft.

Not saying that the transfer case isn't making the noise but I've been on numerous boards for couple years and read thousands of posts. I have never read of anybody ever damaging one of these transfer cases.

Rons 5.3

iTrader: (7)

Ah, the SS is referring to an 02 Camaro SS, I was posting about my suburban....Sorry for the confusion. So would that fork pictured (when engaged) cause the chain and front d-shaft to turn or does the chain turn all the time?
I have 90,000 miles on this Suburban but I bought it used with 60,000 on it. I see that the transfer case has been apart before, but it was before I owned it. I did notice that the front driveshaft has some play in it, and the rear d-shaft has virtually none, but I assume thats normal?

KySilverado

iTrader: (7)

I should have caught on about the SS being a Camaro... All SLP options.

Heck I've been looking at the diagram for 10 minutes now..... late and new years to boot. Yes I think the chain turns all the time. 4wd or not.

Just went out and put a twist on my front driveshaft. It can be spun sitting in park and you can feel just a little play. Maybe an 1/8" back and forth before you feel it spinning things. If that makes sense.

Rons 5.3

iTrader: (7)

Hmmm, mine goes back and forth, but thats it it doesnt spin any further......You have auto trac also, right? I am also wondering if it could be a torque convertor issue. I'm lost on this. I sould also mention that other than this noise there arent any driveability problems, no surging, no power loss...everything feels the same.

Wilde Racing

iTrader: (26)

The chain spins all the time. The front drive shaft will have a ton of play also.
I'd put the truck on jack stands and drive it, see if the noise is made when the front wheels are not spinning, you can also check if the Autotrac is still working. Another "safer" wasy would be to just jack up each wheel and spin it. My truck also makes a noise kinda like the one you are talking about, but mine is the right rear e-brake draging. Just for giggles try applying the e-brake one click and see if the noise goes away...

KySilverado

iTrader: (7)

Yes its an auto trac the NVG 246-NP8 transfer case. Sounds like the front diff isn't unlocked in yours if you can't spin the driveshaft.

I was thinking maybe a flexplate crack.

Wilde Racing

iTrader: (26)

I can't spin my driveshaft.....

KySilverado

iTrader: (7)

okay this is getting strange. Now I have something wrong with my setup

budhayes3

iTrader: (19)

I don't want to add to the confusion, but I thought that the AutoTrak transfer case used a viscous coupler and did not have a chain