I have a question about trans fluid for you pros on here. I am getting ready to pull a 4500lbs trailer 5000 miles from Alaska to Michigan in a couple of weeks. My titan has 34000 miles on the truck and the trans fluid has not yet been changed. I check the fluid and it smells fine, but it is no longer bright red it is starting to fade. I live in a small town in Ak and trans fluid choices are limited. I have found 5 quarts of Royal purple max ATF and 6 quarts of Valvoline MEC/Dex ATF fluid at the local auto parts store. I was thinking of doing a spill and fill because I can only get enough oil to that. Which oil would you fellas go with and will it be okay to just do a spill and fill with either of these oils?