chrizzflo

Hey everyone I just got a 07 c230 sport * with 104,000 miles*. and when I was driving it around at 35 mph I noticed it would not upshift into the next gear... I slowed down and the trans downshifted into 1st but then wouldn’t upshift again. I shut off the car for 10 minutes and turn it on again... I shift the gear selector into drive and it makes the ugliest clunk sound ever! I start driving the car super smooth no rapid acceleration whatsoever and it shifts properly into all the gears like nothing happened. I took it out again the next day and it’s shifting properly no issue. What could possibly cause this?! I’m thinking the transmission may need its fluids changed