Ka-thunk

[Shrek66]

I have a 2004 Yukon XL (SLT) recently I started to notice a ka-thunk sound when going over bumps. The sound is getting more frequent as time goes on.
I crawled underneath the other day and checked my suspension components thinking somthing came loose or broke. I could not find anything there, next the driveshaft and was looking for loose U joints the rear was tight and "looked" good, when I started wiggling the front of the drive shaft I noticed the yoke going into the transfer case had slop in it and made a ka-thunk sound. Just not as loud. Doing searches for related threads I noticed that there is talk of removing the yoke and re-greasing it and it would be ok, others have the yoke being replaced and a nickle plated unit being used. Others say to swap out the U joints also.

Is there a definitive answer? If I swap out the yoke does anyone have a part number of a good one to use? what about U joints? I have read a bout two different greases being used, what would you recommend?

Also is there something in the transfer case that may be bad?

Thanks

 

[dropmech]

Check the security of your spare tire. I was hunting down a similar noise for weeks before I realized my spare was loose.

 

[Shrek66]

I checked the spare like you suggested. Unfortunately that was not it. I think I am going to pull the driveshaft, grease the yoke's splines and see if that does anything.

 

[sumo]

is the noise front or rear? have you checked for broken front stabilizer links?

 

[Shrek66]

The noise is in the middle of the vehicle.