98 Cobra drivetrain noise w/video...need advice!

[shelbygt]

The car just started making this noise. The pinion seal was leaking when I got the car so I believe it could be the pinion bearing. The noise sounds like it is coming from the rear end, but not 100% positive. I do plan on changing to an aluminum driveshaft, as I believe the pulsation the car has from 45-60mph is due to the ds and might be the reason the seal leaked over time.
Here are the vids ... might want to turn down your bass, as it is easier to hear.
[ame="http://video.google.com/videoplay?docid=-5474962282941534080"]http://video.google.com/videoplay?docid=-5474962282941534080[/ame]
[ame="http://video.google.com/videoplay?docid=1281155727899438003"]http://video.google.com/videoplay?docid=1281155727899438003[/ame]
[ame="http://video.google.com/videoplay?docid=-6178344585789334137"]http://video.google.com/videoplay?docid=-6178344585789334137[/ame]

 

[FunkyBoss]

I'm having a similar problem, the rear makes a grinding noise while coasting in gear with the clutch engaged. Your noise sounded different than mine, almost like gear whine. Is it the stock gear?

 

[98 N/A 4V]

Low fluid in the rear that could lead to burnt clutches in the T-lok or like Funkyboss said gearwhine. If the tolerances between the ring and pinion are too tight then whine will occur. -Mark

 

[shelbygt]

From what I know, the car has an Eaton differential 31 spline axles and 4.30 gears. All installed in 02. The car just started making the whining noise, so I wouldn't think it would be incorrectly installed gears. The sound started about a week ago and I could only hear it when slowing or rolling and coming to a stop, but now it is getting louder ever time I drive it. The noise is there constantly, no matter if accelerating, decelerating, or coasting, but it is more noticeable under decel.
I checked the gear and trans oil and both are full. When I got the car, I replaced the rear diff. seal and there was way too much oil in there, as I think the PO filled the level to the fill hole on the after market cover, so I changed the fluid w/modifier to the factory level hole.
Short of having the rear rebuilt, is there a way to determine where the source of the noise is?
Thanks,
Dave

 

[STAMPEDE3]

Hard to tell from the vid.

Either rear end or input shaft bearing.
Most likely rear end.

 

[c9obr6a]

check pinion for play up and down / and rear outer axle bearing. Might be a cruch collar issue or bad bearing.

 

[98 N/A 4V]

Crushed colliar will definately you get gear whine. I speak from experience. -Mark

 

[PACIFICGREENSVT]

snow tires? JK