[scottybye]

2009 Chev Silverado
5.3L V8 Auto
61,000 miles
All stock
Single owner
Always regular engine oil changes (myself) but never any tranny, diff, antifreeze, or other fluid changed up to this point.
Recently I starting noticing an abnormal noise that I have never heard before.
Best way to describe it (it sounds like a front tire rubbing on a mudflap when making a turn). (I dont have mudflaps...)
Kind of like humming.
My truck has the auto 4x4 option on the dash and I have always driven with it in AUTO.
So I took the truck into the dealer to get some input and diagnosis.
The tech took it for a test drive and told me that it was the 4x4 system making the noise and it was possibly on its way out.
And would likely cost thousands to repair.
He also said that it was like caused by driving in AUTO mode for most of the 60,000 miles that I put on the truck.
Told me to start driving in in 2wd only and that the noise should go away. Which I did and sure enough. The noise goes away in 2wd.
Wondering what you guys think it could be and what I can do to get it fixed or if there are more things I should be checking.

Thanks

https://lh3.googleusercontent.com/KNiIC ... r9IzI=s114

 

[ferraiolo1]

ThatS your problem. You had your front differential engaged for 61000 miles. Auto 4wd isn't the same as AWD. continue to only use auto 4wd or 4wd when conditions are slippery.

Sent from my iPhone using Tapatalk

 

[scottybye]

Thanks for the reply.
I looking to see if someone has some input now as to what damages may have been done by driving it that way.
Have I severely damaged something. And is it a big repair?

 

[ferraiolo1]

There were a few other guys on here that made the same mistake a few months ago. They changed their transfer case and front differential fluids for now, with no updates.

But that's what I would do for now if I were you

Sent from my iPhone using Tapatalk

 

[scottybye]

I can definitely do that.
Do you have any recommendations on what fluids to use in each

 

[ferraiolo1]

There is another how to for your transfer case somewhere. On here also

How to Change Front Differentail Fluid

Sent from my iPhone using Tapatalk

 

[scottybye]

I will have a look. Thanks

 

[Gozzie]

Ive said it before and will say it again, they never should have put the auto switch on these things.
At the least it should reset at key off or something like that.
People think it's like AWD and it's not.

I don't blame the owners so much, auto sounds so user friendly.

 

[scottybye]

Yes I agree if it was going to cause problems I would never have used it. I actually though that it would just engage when needed. I hope I didn't damage things to bad.

 

[Gozzie]

Just do as ferraiolo1 suggests and change those fluids out. I imagine they are pretty used up.
If it's running good in 2wd I wouldn't worry too much unless you 4 wheel it a lot.

 

[ferraiolo1]

It only engages your transfercase when needed but keeps everything upfront engaged. You should see an increase in mpg with it in 2wd also. Auto is meant when driving on a road that's off and on slippery

Sent from my iPhone using Tapatalk

 

[scottybye]

I will at first chance.
Are there 2 different components and fluids
1 - transfer case
2 - front drive
Or are they actually the same thing

 

[Gozzie]

They are different
Transfer case is transmission fluid and the differential is gear lube.
It will tell you the type in the owners manual.
If you don't have one you can download one right here from this forum.

 

[scottybye]

Thanks
I do have all the original docs with the truck.
I will check and go from there

 

[jwstrout]

Being as it has the "Auto" function, the transfer case likely uses AC Delco Auto-Trac II. It comes in quart bottles, is blue in color, and is a dealer only fluid. I'd use a good synthetic 75w90 gear oil in the front differential.

Jeff

 

[Gozzie]

Being as it has the "Auto" function, the transfer case likely uses AC Delco Auto-Trac II. It comes in quart bottles, is blue in color, and is a dealer only fluid. I'd use a good synthetic 75w90 gear oil in the front differential.

Jeff

Not wanting to argue but I would double check on the Auto-Trac ii. I believe his newer truck would take the dexron Vl . I do not know when they switched over though.

 

[ferraiolo1]

Owners manual will tell you what you need

Sent from my iPhone using Tapatalk

 

[jwstrout]

Gozzie,

No arguing here.....I just know my old Tahoe with the auto function used the Auto Trac II. I have no doubt they could've changed. Dealer only fluid is a joke.

Jeff

 

[scottybye]

Just got a quote from my local dealer on the fluids...

Transfer Case = Dexron 6 ATF @ 2 litres $4.85/litre
Front Diff = 75-90 Synthetic Gear Lube @ 2 litres front & 3 litres rear $13.69/litre

Now just to find time and a warm place to do this... temps below freezing here in Calgary this week.