Just got my car back from a clutch, flywheel, pressure plate install + a tcase swap

Problem is, the car was returned with a terrible "knocking" style noise (in the sense that it goes knock-knock-knock-knock) coming from behind the driver's seat or rear of the car. I can't really pinpoint it and I honestly haven't driven it much because I have no clue what it could be.

The noise is consistent with speed and is most prominent at lower speeds. There is no vibration associated with the noise, and it doesn't appear to reverberate off of surrounding cars or walls. There is no noise if the car is free-rev'd. At higher speeds (60-80), there is no loud whining aside from the poly bushings in the rear diff area. The knocking still occurs whether the car is on or off, doesn't matter, as long as it's rolling.

So far I've checked the driveshaft carrier bearing supports, and they're all installed snuggly.

Any ideas? I'm completely lost this time.
Just for clarification, it almost sounds like a bad CV joint, except it occurs whether I'm going straight or not

 

no fluid leaking?

im going to take a wild guess, but check the output snout of the transfer case to the driveline.
look around there and check for play, or if its in contact with something.

its tough to diagnosis this, have u considered taking it back to the shop that did it? usually they warranty their labor.

 

Thanks so much for taking a shot at it

I've been watching the car for a bit and haven't noticed any fluid leaking.
By snout you mean this part here? http://i816.photobucket.com/albums/z...f/36f69e2b.jpg

I went underneath and took a look earlier and didn't see much In terms of looseness or play. You're right it's hard to diagnose, I'm practically lost and I'm not even sure where to begin.

What's the possibility that a single axle or half shaft could be improperly installed causing this issue?

 

Place the vehicle on four jack stands. Situate the stands so the full weight is on the control arms as close to the tires as possible. This will simulate the vehicle fully weighted as though it is being driven. The axles will be at the correct angle so you can accurately diagnose the noise. Start her up and put her in gear. You should be able to locate the area the noise is originating from.

 

Took a video this morning from the footwell of the back seat. It was louder there than the front

Phone won't let me paste. Guess I'll update at home Lol

 

Okay, video's been upped here:
Mechanic who did the install said the lift wasnt available today, so I got underneath the car when I got home. It's a bit difficult to pinpoint exactly where the noise is coming from, but it's loudest in the trunk. My guess is the rear diff is making the noise and it's resonating through the trunk?

Just to confirm: Driveshaft is not making contact with the body, heat shield, exhaust at any point. No visible slop in the carrier bushings or u-joints either. Also, there's no vibration throughout the car... only this noise.

Would it be a diff bearing?
It's not a problem if I have to buy a new diff. That's not what's bothering me.

What IS bothering me is the fact that my car went in for the clutch job WITHOUT that noise.

 

Did the shop that did the work specialize in Evos (or at least knowledgeable about them)? Why not take it back to them and tell them to diagnose and fix it?

 

Claimed to be knowledgable and has been a customer of mine for some years. As to why I'm not going back there, what I thought of the guy last week isn't what I think of him this week. Let's just put it that way.

I plan on taking it somewhere else to diagnose, of course spending more money, but I guess i always try to figure it out on my own first. That's where you guys come in Lol