I have a 98 SL500 and I have been having problems with the transmission not shiffting sometimes. It will just stay in 1st or 2nd gear for a few minutes then shift normal. Also when I'm driving at cruising speeds the trans will downshift to 2nd gear on its own. If I put it in nuetral and back into drive several times it will eventually shift normal. But usualy it will just upshift then downshift several time then clear up and act normal for 3 months or so. I went to dealer and they never heard of it so I'm hoping someone here as heard of this problem and can maybe help me. I already changed fluid and filter and the oring for harness going into the side if trans. I also checked for codes and found none. Any help will be greatly appreciated.