03 Yukon Xl Denali 6.0 Clunk/Growl/Whine Front End

[YukonXLDenali6.0]

Hi, 03 Yukon Xl Denali 6.0, 225,000mi, bought it at 222,000mi. Has a growl/whine noise in the front end after a long stretch of highway speed, while slowing down decelerating/braking right before coming to a stop. It also makes a clunk sound as I accelerate out of a low speed turn in the front end. A slight delay in engaging and clunk. Have been reading on several forums. Front differential or transfer case? Possible rebuild or replacement? Low fluid, shavings, bearings, etc.? I’m unfamiliar with AWD. I do have records of a rear differential replacement less than 10k ago. Doesn’t sound like it’s coming from the rear.

This stuff may be unrelated but want to give as much info. possible. it does clunk putting it in reverse from park. If I’m in cruise at highway speed, coast to reduce speed and re-engage cruise, I hear the similar clunk as accelerating out of low speed turn. I also disengage the traction control before I leave because it can be set off from acceleration while turning from a stop sign.

Any information, links to info, or questions are appreciated. Thank you guys.

[shorod]

The first thing I'd inspect carefully are the front wheel bearings. If worn they can cause the growl/whine noise as well as the clunk sound. Additionally they could explain the traction control engaging at low speeds (experienced that on my dad's S-10).

The clunk when shifting to reverse is a common sound on these GM trucks. GM issued a Technical Service Bulletin (TSB) for it and even re-designed the transmission output shaft with a different (nickel?) plating to help reduce the chances of the clunk. I don't recall what all years were effected, but it's worth looking in to.

-Rod