Got a leak on the rearward seal of the torgue converter. At higher speeds the fluid hits the HOT muffler and sprays on the rear window. Is this an easy fix, I mean for someone with moderate mechanical skills? If I cannot get it changed, could I top it off before a short trip? If so where to top off? It only leaks at high speeds, daily driving is OK... Also I will be changing oil soon, what do you recommend for SC weather Mobil 1 10-40 with a Mobil 1- 301 filter? Advance has the 6 quarts of Mobil One on sale with your choice of Mobil one filter for 29.99 until Sept. 30th.

 

How do you know it is the torque converter leaking and not something else?
Lots of things under the truck to leak.

 

The fluid is coming from the rear seal, not above, or in front of.

 

You will not want to take your Disco on a trip if you have a pressure seal leaking. No, you won't want to remove the tranny and it should go to a tranny shop to be looked at.
The 10W/40 will be OK in your area, unless you get into a lot of 20 degree mornings then I would suggest 10W/30.

 

The bottom number on motor oil is how well it pumps when cold, so 10w-30 and 10w-40 will pump at the same rate when cold but 10w-40 will give better protection when hot that 10w-30 will.
http://www.carbibles.com/engineoil_bible.html