Land Rover Repair: Transmission on 94 Range Rover, drive shaft, transmission shops

Question
I have a 94 Range Rover with 160000 miles.  I have taken it to 2 transmission shops and recieved 2 different answers.  When it shifts from 1-2 after it has warmed up it tends to shudder or vibrate slightly.  1 shop said it was an internal tranny problem and would not change the dirty fluid and that the tranny would need rebuilt. The other shop said they found the front drive shaft had slight play and this was causing the vibration or shudder and it would cost about 1000 to fix and replace the fluid and filter in the tranny.  I have placed a bottle of Lucus in the tranny and differential and that seems to have made the shudder less but it is still very noticable. I was wondering you thoughts on the problem and how long the Lucus will hold off the problem  Thanks!  

Answer
My guess is that you have a problem inside the transmission.  If your front drive shaft has play in the joints it's important to fix that propmtly because the driveshaft could come apart while driving and do extensive damage.

I'd guess the drive shaft and transmission are two separate problems.