2004 Cummins Ram Noise - Transfer Case?

[GrolarBear]

I've heard this noise a few times before (video linked at the end), the truck made it for a few seconds and it went away. Last night it started, got worse, louder, and did not go away. It seems to be coming from the middle of the dash/floor/firewall and is speed dependent (not rpm). When starting from a stop it doesn't become really noticeable until about 15mph, but then it keeps making it until you come to a stop.

Any thoughts on what it is? How to figure it out? If it's the transfer case like I suspect is it something I can split the case and fix/replace or am I looking for a replacement?

https://youtube.com/shorts/wd5KRfEUV1Q

 

[Dennis Shellito]

The first thing I would advise you check would be the front drive shaft u-joints and the CV joint. If it is something loose in the front shaft you will want to get it fixed because it can take out a lot of stuff, some of it expensive, if it comes apart. BTW, the front drive shaft turns even when in 2wd.

 

[GrolarBear]

Click to see:

More testing, follow up, and fluid drain

 

[usmilret]

Sounds like your transfer "chain" inside the transfer is loose. I wouldn't be driving that truck any longer until you drop the transfer and split the case open to inspect it.