So I have a 99 disco 1 and it started to make a rattling noise from what sounded like the frond drive shaft so instinctively I changed out the u joints. But I still am getting the same popping noises from the same area. And my transmission whines really bad and it has a slight grinding noise while it's in gear. What are your thoughts

 

my thoughts? it sounds like its time for a trans rebuild...

 

Should I try to go through the fluid and filter routine first

 

Have you checked the fluid level in the transfer case?

 

I was going to change the oil in it today with some 85w-140 along with both diffs so I'll see how that goes

 

There is an inspection plate on the t/c. I would pull it and see what the innards look like.

 

Will do hope fully is should get it done by today. But on another note I'm still getting a popping/rattling noise when I accelerate like its bad u joints even though I replaced them. Freaking rovers.

 

When were the wheel bearings last packed or replaced? If not recently or unknown, I would pursue that route. Jack up the front and rotate the wheel by hand. See if you feel or hear anything.