Chattering Transfer Case Question

[orvis17]

So, after looking through tech links today, I might as well ask my question as well.

Drive train is 350, H55f to a split transfer case. History is unknown, but the H55f is new, but no history on the transfer.

Hubs are in locked position, been left in that position for a couple months, not a daily driver, and by no means much pavement travel.

So the issue now is, when when the vehicle is in 4hi or 4lo and not under load, (coasting after letting off the accelerator) I now a a chatter...2hi...no chatter even with hubs locked... climbed underneath and found drive shaft nuts loose, but not off, so I tightened those up on the transfer side. No others were loose, either on the front drive shaft or rear, just the four that I tightened. Get back in happy I found the issue...noise is still there, so what do I check?

It is in the shop un-thawing as we speak and will get a chance this weekend to check it.

So,
1. Oil...(no leaks, but maybe, and obviously the easiest to check!)
2. ?
3. ?
Thanks in advance!

 

[Poser]

Grab the drive shaft right at the front output flange where you were working and shake it, hard. Is there any movement?


Next move down the front shaft to the slip and stub joint. Grab that and shake it, hard. Is there any movement?

 

[EWheeler]

I have the same exact issue. Anywhere above 20 MPH, nasty chatter when 4wd is engaged and I let off the throttle. Back on throttle, no noise. I have shaken the driveline as Poser suggested and everything feels tight. I have an older one piece case, not sure how different these things are internally. Looking forward to seeing what you find out.

 

[orvis17]

going to go shake it now....























uhhh...yeah!

 

[orvis17]

Okay, very minimal play, almost none...anywhere...
Started at the back of the transfer shaking, then to the back of the drive shaft, then shook the front shaft at the transfer case, then worked toward the front...
Only play at all was in the front slip joint on the drive shaft, and when I pulled sideways on it, it kind of gave in the direction of the pull. That was it.
Been reading the tech links, and some have issues with oil draining from transfer to the tranny...could this be it? I have not witnessed any oil leaks, and have not checked the oil yet, will get to that this weekend.

 

[Poser]

I failed to mention that you need to have the drive line free from load, ie it cannot be in gear and the parking brake cannot be on.


Chock the wheels and make sure the transmission is in neutral.

Check the transfer case oil level.

24mm socket.