2005 XTerra front end noise (not squeak -- clunk)

[Encryptshun]

As title says, I have a 2005 XTerra. It's an A/T, 4WD with towing package.

For the last few days I've heard a strange machine-gun rattarattaratta coming from the front end whenever I'm slowing to a stop or taking off. I checked out the front brakes for pad wear, slipped backplate, loose caliper bolts and rotor warping but can see nothing. 99% of my driving is in 2WD mode, but this morning I put in in 4WD to see if that did anything. The noise stopped. When I put it back in 2WD, it came back. The sound sounds kinda like if you ran holding a stick in a picket fence, but metallic rather than woody and dull.

The vehicle has 57K miles and has been immaculately taken care of (by me).

Any ideas what it could be? Thanks in advance.

[Big-Bird]

Yikes! That's not good dude!

Lift the front end and spin those wheels by hand. Listen for mild grinding or rattles.That noise could be coming from the front differential or the CV axles or even a bearing.

[Encryptshun]

^ Thanks!

I ran out of options, so I took it into the dealer yesterday. Nissan 5 yr, 60K mile powertrain warranty applies. Stupidity pwnz me because I forgot that this was covered.

The details I got from the service manager are sketchy at best (I asked to speak to the mechanic but was not given that chance), but what he said was that a new "driveshaft assembly" will need to be put in. How the hell does Nissan kit these parts nowadays? I mean, I'm now guessing they think it's the u-joints, but why the hell would you need to swap out the whole driveshaft just to replace the u-joints?

Weird. Anyway, part is on order and I should be getting it put in on Saturday. The manager said that it was safe to drive until then.

I'll update once the "fix" is done. I'm still betting it's the front transfer case and that they are replacing parts in increasing order of cost since it's a warranty situation, but we'll see.

EDIT* Okay, after looking at the parts explosion on Courtesy Nissan's website, I see that he was talking about what I'd consider the front axle rather than the front propellor shaft (which I would call the drive shaft).

[Encryptshun]

Okay, the issue is fixed. It turns out that the front U-Joint for the forward propeller shaft was causing the noise. Since it was under warranty, the dealer replaced both propeller shafts, including U-joints. Not sure if that means that you have to replace the whole shaft if one U-joint goes bad or what, but that's what they did (and since it didn't cost me a dime, I'm not arguing).

However, having this issue at 58K miles is a bit