Auto 4wd 06 noise ???

[LouBoxer]

Just got an 06 Sierra and put it in Auto 4wd on dry pavement and when I drive really slow like from a dead stopand turn really sharp it makes some noises like clunking. Its fine when driving up to speed though. In 4wd high it makes some mild noises when turning really sharp from a dead stop on dry pavement but I think they are more normal.
I was told that its because I am on dry pavement and they should only be used in slippery situations ??
Suggestions appreciated.

[bighaas79]

4wd on dry pavement and sharp turns isn't the best idea, no. It's possible you have a bad cv joint in one of the front axles but without hearing it, it hard to say. You will get some noise out of the front when trying to turn on dry pavement when in 4wd because the front end and tires and pavement are all kind of fighting each other.

[biggsteve97]

You may use Auto in any condition even dry pavement because the transfer case is only engaged when 4wd is needed.

[LouBoxer]

Auto is where the problem seems to occur. Its fine up to speed but slow turning is not good.

[biggsteve97]

Originally Posted by LouBoxer

Auto is where the problem seems to occur. Its fine up to speed but slow turning is not good.

turning would indicate more of a cv joint issue or a wheel bearing. in 4wd even auto since you are turning more parts it does change the amount of stress on the joints and the wheel bearings. check those.

[LouBoxer]

So if everything were fine..... In auto I should be able to turn tight on dry pavement without any noises ?? other than the normal 4hi noises ?? This sounds different more of a clunking sound.

[biggsteve97]

Originally Posted by LouBoxer

So if everything were fine..... In auto I should be able to turn tight on dry pavement without any noises ?? other than the normal 4hi noises ?? This sounds different more of a clunking sound.

correct. there should be no noise difference in auto than there would be in 2hi. I have an 03 Tahoe and an 02 Silverado both with the Auto 4wd as well as I used to have a 99 Silverado with the Auto and none so far have made any noise in Auto on any surface. They only time any of them made noise in 4hi was if I pulled on to dry pavement and forgot to switch back to 2hi or auto and that was mostly tire noise from the drive train binding. you may have a t-case or front diff going out if you have noise in 4wd. check fluid levels and the front driveshaft. My old 87 half ton has a full time t-case in it and I get a clunking noise on tight turns but it has a a bad front driveshaft slip yoke allowing lots of slop.

[BlackhillsHD]

I always tell customers to avoid using auto. The clutch pack in the the transfer case is modulated to the amount of slip. This means that if you are using it when you dont need it, it is causing the clutch to constantly slip. I only use them in wet conditions.

On yours I would make sure that the t case has the right fluid. GM's recomended fluid is Auto Trac II. To know if yours has it, it should be blue in color. That is where I would start. If it doesn't have it, it could be causing the clutch to grab too much in auto.

[LouBoxer]

Took it to the dealership since I got a warranty with the truck. They replaced the whole transfer case. Part alone was $2100. Glad I got a warranty. Previous owner was a woman...she probably drove with the auto on alot and ruined it.
Its a stupid system and don't understand why they would build an auto system that was not really auto Oh well I won't use anything but 4hi and only when its icy.

[67ChevyRedneck]

Wow, glad to hear an extended warranty actually worked out for someone! I've never used my auto 4wd. I never liked the idea of it. I use 2hi or 4hi only. If you ever read consumer reports (I know, I know, most of their crap is BS) but in general, even vehicles that have a good rating for fwd, their awd versions are usually much more problematic. I wouldn't buy an awd vehicle either. You either need 4wd or you don't.