Mine is the same way. My tranny has 225k on it. I am getting a little slipping in OD. I do have a shift kit installed. But I was warned NOT to do a flush. I was told it would break loose some deposits that were built up and could cause problems if they get lodged in the tranny. Right now I am just going to do a filter and fluid change and then this winter I will be getting a new tranny from ZZP.