Front differential or transfer case

[Brian Wilson]

This is a short video of a sound my car is making. It happens most when I take off fast but also when I'm going slow and punch the throttle. I can control it by taking off slowly and not outting much torque on the drivetrain but when i tow a horse trailer, it is almost impossible not to hear this sound. I have changed both the front differential fluid (IFS series 900 with barely any metal on the magnetic plug) and the transfer case fluid (bw 4485 with dexron 3. Fluid was dark but absolutely no metal particles in old fluid). It sounds and feels like a mechanical failure. Maybe gears slipping due to wear or bearings gone bad?it also feels like its near the drivers front floor board. But I realize harmonics can trick the ears.

I have never repaired a 4x4 or awd before. My only other 4x4 was a 96 grand cherokee online 6 and it just ran. Never had any trouble with axles, driveshaft, transfer case, differentials, splines, trans or whatever with it so I'm unfamiliar with this noise.

 

[Brian Wilson]

Ok. The video doesn't sound like it really picked up the noise. At least thru my phone speaker. Maybe headphones would be better. But it sounds kind like gears grinding. And it does it only when I work the drivetrain hard. Maybe even a chain skipping teeth on a sprocket but I can imagine a sprocket being worn down that much. And the lack of meta shavings kinda kills that idea. It doesn't sound like a bearing gone bad. Unless it's a bearing with seriously worn flat spots.

 

[Ponchonutty]

Any idea what this sound was?

 

[Brian Wilson]

Front differential. Had to do a complete rebuild. Good time to drop some shorter gears in. In my case I was not able to.