its not a wheel bearing period. the car makes the noise in the air. No loads needed. The chassis ears and stethoscope keep pointing strait into the transmission to where the center differential lies.

Im going to be pulling the transmission again .. Something had to be missed.

 

The transmission does not have a differential. You mean transfer case right?

I'm watching this thread like a hawk. Your doing a good job Keeping us posted, thanks!

 

Actually, the mechanical portion of the center different (spider gears) are in the transmission, while the limited slip (viscous or hydraulic) is in the transfer case on the passenger side. The rest of the transfer case houses the front differential.

It's a pretty complex design with three concentric shafts. Outer shaft for center to rear, middle for center to front, and the most inner shaft is the driver side front axle.

 

BlueEvoIX,
my car makes the EXACT sound yours does... except mine is much quieter and only happens at 65mph.

I noticed my whine after a 1-2-1 money shift.... I probably hit upwards of 10k.

In for results!

 

weirdddd....sounds just like a wheel bearing. Seems like usually if its the Tcase its more high pitched.

 

ha.. thats how this noise in mine developed. but unfortunately it wasnt me driving .. I rather had messed up my car then a friend.

I looked over when it went back in first and it was pegged past 9k and then it came down. So it was definitely about 10k

Ill keep you all posted .. Its just starting to become bothersome to get time to pull my tranny with my work taking up 7-7. good thing she's not my daily

 

sounds like a transfer case. a wheel bearing is more of a grinding noise.

 

I got a nasty whine after a 1-2-1 shift aswell. Turns out it was the tranny.

But I replaced it and still have a stupid little whine. about 2 years people said it was my transfer case. Well been driving on it ever since and the noise is still there and my car runs fine.

I'm beggining to think this car just makes noises left and right. Imagine when it's 10 years old? It will probably rattle untill it falls apart.

 

I am the one helping diagnose this car locally. I have had the tranny and t-case apart and found nothing wrong visually. Here are some important notes that may help .

The car does not make the noise when accelerating.
It does not make the noise when decelerating.
It only makes the noise when at light cruise. This is when every splined joint in the drivetrain is shifting back and forth between loaded and unloaded. It is that action that makes the noise in this drivetrain.

there are no less than 16 splined joints in the awd drivetrain. each one adds a small amount of play to the drivetrain. when you are accelerating forward and suddenly reverse the drive load at high speed every single joint in the drivetrain gets stressed to the max. it is like subjecting each joint to a very high powered impact gun. VERY HIGH POWERED.

as these vehicles get driven these splined points become looser and looser over time. so you wouldnt thing one sudden jolt to these splines would create an issue from some new found looseness. cars with well over 100k miles are not exhibiting this problem when they certainly have more play than this car.

 

Splines are where my transfer case/transmission failed. At the splines that connect the center diff to the front diff (middle shaft) where the transfer case meets the tranny. The splines completely stripped off.

 

Transfercase for sure cause mine is making that noise aswell....

 

did you measure the teeth thickness on the crown of the transfer?
i had a similar noise on my car, and when i pulled the transfer apart the teeth of the crown gear has worn down so much that there was a burr on the top of the tooth for excessive wear.
i had been drag racing the previous night and the sound got worse. After looking at it and seeing what had happened, i was surprised it just didn't shear the teeth off. Just goes to show how strong these items are.
Just a thought.

 

in for the final result

 

The t-case internals look perfect. It has been apart two times now. First when the tranny was freshened up. It was cleaned, inspected, reshimmed. Then a second time as we thought we may have missed something. The gear teeth and bearings look new. as well as the splines. I have seen three broken input splines and maybe a dozen worn ring and pinions from t-cases over the years. There is no visible wear on the teeth.

I have a new thought on this. I am wondering if its possible that the viscous coupler is damaged and causing chatter. This sounds very plausible to me. Unfortunately the viscous is factory sealed so there is no way it can be inspected or tested. would just have to swap in a known good one to see if problem goes away.

I have seen a few aftermarket clutch pack diffs that didnt break in correctly. the clutch plates dont slide over each other smoothly. they chatter and cause very annoying axle noises.

The factory viscous is a clutch pack diff that is sealed. it is welded together with a very thick weight oil inside. I am thinking the sudden reverse motion may have scarred the plates and now it has chatter. This would fit the characteristics of what is going on. the center diff is differentiating anytime the front axles are moving and different speeds than the rear axle. This would happen on any set of tires that has more than 500 miles on them. this would also happen in the air on the lift as a doubt very seriously the front and rear load during freewheel is exactly the same.

the more I think about it the more I like this idea. If this were my car I would swap in another t-case before reinspecting trans.

 

Fre,
do you have pictures of this? I think I understand what you're talking about. Ill have to pay close attention to it when I get it apart here soon.