2000 Yukon XL 4wd clicking speed related? -- moved from incorrect sub-forum.

[Oshkosh]

Hi,
Great forum...
I just purchased a 2000 Yukon XL slt 4wd 130k miles, After approx 15 miles of driving I hear a speed related click, click click, I think coming from the front of the truck.
It isn't engine related or trans as rev motor and I put in neutral and still click click click speed related.
I jacked up each corner and spun each wheel in the yard and cannot duplicate the noise.
I put on brake pressure on and the click doesn't change, I turn the wheel left and right and the noise doesn't change?
Almost sounds to me like a cv joint going bad but the boots are good and no excessive play there...And it doesn't do it all of the time????
I know it would take a crystal ball but any ideas?
I am still checking fluid levels etc,just did rear brakes/parking etc.
Thanks in advance

Besides posting under the wrong year I have an update...I checked both diff's and transfer case ,all are full up to level... I am changing diff fluids while I am here..
Need to get gm/smurf for transfercase..

 

[Oshkosh]

Update, while the Yukon is up on ramps/stands draining my fluids I grabbed the front drive shaft and the front diff is locked in, I have the front on ramps.
I noticed the other day on "tight" turns it was grabby (1st clue) .
The dash button says 2wd and seems to function properly but I am pretty sure 99% it is either in 4wd high or the front diff is engaged.
I grabbed the proper GM blue fluid for the transfercase and will flush that.
Not being sure what is in there having just purchased the truck.
I went threw a similar deal with a 2000 AWD Bravada having the wrong fluid, grabbed all the time on turns.Flushed it a couple of times and it fixed itself..
I hope I will be that lucky with the Yukon xl...Or the 4WD Actuator has gone bad which seems very common.
Seems GM has it engineering issues like all others.
Any other thoughts would be welcome...

 

[chauncey0337]

Welcome. Sorry I can't help you as I'm not very knowledgeable in this area. Good luck.

 

[Oshkosh]

Thank you...
It is a process sorting out a new used rig ,once I get all the fluids and filters changed I will dive head first into the 4x4 issue. I am leaning towards the front diff actuator...
Trying to do five things at once isnt working.
Working outside I am at the mercy of mother nature at this point.