I have a 1982 300TD (215,000 miles) and I changed the transmission fluid (w/filter change) last week. I am trying Mobil 1 synthetic for the first time. Before I was just using non-synthetic. Now I am having some slippage between 2nd and third. This only occurs when the engine and transmission are not warmed up after about 10 miles it works normally. I checked the level and it is fine. The transmission shifted fine before the oil and filter change. Thanks. Eric