If you are a little mechanical, PM me your number and I'll walk you thru what to check.
For the most part the tranny can't grind so more then likely it is your t/case and or possible diff issue.
Also, how do you know the engine is from a P38, and a P38 tranny won't work in a D2.

 

Here is a link to a thread a few months ago I started about a vibration in the transmissino.. This may refresh your memory of what issues I had

https://landroverforums.com/forum/di...g-still-55187/

 

SO the trany won't grind unless I blew up gears I assume.. and I didn't do that
The Torgue converter won't grind??

Also I had that lound whirling noise in my truck while driving a few months ago as well.. here is a link to that

https://landroverforums.com/forum/di...ing-out-57715/

could This whirling noise and vibrations all have been coming from the transfer case?? Fluid leak out or it just went bad??

I have not noticed any fluids on the ground under truck other than oil..

 

I am not big on chasing down old threads.
If you want some help, PM me your numbers so I can walk you thru what to do.
Still curious as to why you thing you have a P38 tranny??

 

Go - 3 MPH in Neutral. Or have a friend push you.
Try to move the transfer case shifter FORWARD to get you into low range.
Then see if it still grinds.

If it does. go to transfer case N on the small shifter and see if it grinds.

Then go back to "D" on the small transfer case shifter.

If the torque convertor was going bad - the truck would have juddered all the time off the line in 1st gear.

 

diffs have drain - what come out should look like fluid, no silver or chunks.

TC has drain with magnet plug on mine, should not be fur coated. Inspection plate if you drain it and want to check for missing teeth.

If TC is in "N" or blown out, vehicle will roll with tranny in "Park".

 

OK I just went back to the truck to show my friend the sound.. The loud noise its making happens while in PARK it makes the same noise whether in drive, reverse and in park..

If its in PARK that should cancel the Transfer case and the transmission right??

 

I walk up, turn engine on, give a little rev to the engine, and all hell breaks loose underneath.. my friend jumped back from the truck thinking it was going to explode

 

it is the opposite. if small tcase is in neutral it should cancel park and all else. it will roll in park if the tcase is in nuetral

 

Why not drain the fluid and see which one has metal in it, simple but very easy.