My mechanic has told me that the transmission fluid in my 2005 Chrysler T&C is dirty and needs to be flushed and replaced. The van has 118,000 miles on it. I bought it used with 96,000 miles, and I don't know if or when the transmission has been serviced. I am having no symptoms of transmission problems. When I check the transmission fluid, the fluid is clear and pink - however, when I wipe the dipstick on the paper towel, there are a few black smudges around the edges of the pink. Does my fluid need to be changed? Should it be flushed, also? If it has never been serviced, am I asking for trouble to flush it with 118,000 mile on it? Thanks in advance for any advice.