2010 CC 4x4 5.3 36k

Anybody have a noise coming from transfer case ( I think ) not a wheel bearing / tire checked all that ...........not an engine noise .....

Whine that is most pronounced during decel or light load not when accelerate or constant speed ........you hear the most between 20-30mph ...... noise is the same with truck shifted into neutral and reved .does not speed up .......so IMO drivetrain ...same in 2wd or 4wd / auto

Truck still on warranty but I installed 4.11 so "if" this the diff ..no warranty but seems to be from transfer case ............ any ideas

 

Start by checking the fluid level and if there's any metal on the magnet
And to confirm...4.11's rear AND front diff right?

 

Yes plan to change fluid and see if any junk in it .........yes 4:11 in front and rear they have been installed for about 30k

Interested to know if others have had a transfer case problem in the NNBS

 

Depending on when the truck was initially purchased it could still be under warranty. If it is within warranty period I would def take it in usually the transfer case is junk when they start making noise. They are trash can transfer cases for the most part scrap them and install a new or salvage yard one. When they die they destroy everything internally. Make sure stock tune is back in pcm and transmission before taking it in.

Unless it's a diff that is not quite perfect and making noise as the miles stack up and the clearance begin to open up. Usually tcase noise on these are crunching grinding wont shift correctly or stuck between gears.

Check the oil bout all you can do after that a tear down is next step. But if it's out of or low on oil the damage is done.

 

Not low on oil ........but have not drained it yet ...........Yes still on warranty ........I had not thought the tune would be something they would check when doing a transfer case .......Thanks for heads up I will reload stock tune

 

Any major powertrain failure digital pic of pcm CVN numbers is required for engine, trans, transfer case, or differential failure before TAC will approve a replacement should it be proven the component has failed or is un repairable.
Just a heads up!

FYI Don't say a word about the gears if they say it's a diff noise tell them to stop right pick truck up take it home so they don't sack you with a ton of labor diagnostics should they get into it then determine the gears were changed. Then they can backcharge you for labor and put a warranty block on the truck.

 

Got it thanks ..........so I take it transfer case noise / failure is not uncommon in NNBS trucks

 

Nope fairly common not anywhere near pandemic but we see them often enough. Usually bearing failures due to poor quality made in china junk bearings.

 

Won't the truck throw codes of some sort with the stock tune and 4.11 gears? Just curious. I've read about wheel speed sensors screwing up abs or something like that.

 

You can be tweaked for gears only and usually be ok. I've had a couple with gears and they never looked twice. Everything else needs to be completely stock.