240 240 grinding noise:rear

Thanks for reading! I have a 83 245dl. It has started to make a bad "grinding" "crushing rocks" noise from the rear end that is changed with speed. It is not constant and seems to only happen on cold days. Original thought it was the e brake but I do not think so as I hardly use it and I've pulled it a few times to try and cure the noise to no avail. The noise will go away why turning though, and after maybe a mile or two it will stop. I am not sure if it is the diff, hub, or drive line, or brakes. Any possible insight on this problem?

THe only way to know is to jack it up and have a look.

To me, the thing that makes the most sense would be a bearing, but truthfully that's strict nonsense without more info.

Get it in the air and see what's what!

Out of curiosity, did you check/change the fluid in the rear?

I have not, though that is one thing I have thought of as well. I've had the wagon for a 1 year now but I down it has been changed