I just finished installing a brand new front prop shaft. Made sure all Ujoints were greased and tightened everything to spec. When I took it for test drive it still had the front end rattle just not as bad as my last shaft bc it had some worn unjoints. There is also a little bit of resistance to accelerating and heavy vibrating.

I jacked it up again and re-checked everything and noticed that both front and rear shafts have play at the diffs and at the transfer case.

Can anyone help me diagnose this problem? Is it an issue to the front diff/axles too? If all else fails I'm going to just run it in RWD with the center diff locked.

Just took off the front prop shaft and put the car in drive. Looks like the noise is coming from the front output part of the transfer case. The flange that connects to the prob shaft doesn't have any play but what ever the flange rides on seems to have some play. The noise is a steady rattling noise that happens only in drive and reverse but a lot less in reverse.

Welcome, you might get a better response by identifying your vehicle model and year and also posting this in the vehicle appropriate forum.

Best of luck!

thanks for pointing me in the right direction!