I have a 2003 S Type with 124k miles, tranny seems to start slipping under 35 MPH. What could the problem be?

 

I have a limited knowledge of automatic transmissions, however, when/how/with what did you replace your auto transmission fluid. The good news is that is likely not your torque converter. If your tranny was slipping at higher speeds, it would be the converter. The bad news is that is likely a slipping cutch or a blocked path in the trans. I would change the trans fluid if you haven't already.

 

Another possibility could be slipping bands. At any rate, if after you change fluid and the problem still occurs, go to a transmission specialist. If it doesn't get fixed rather quickly, you could have hard part damage which will be fairly costly to repair.

Mike

 

Well it occurs througout at low speeds as well as high speeds. The engine revs high and then I feel a lurch when it catches. I haven't done anything to the fluid as of yet.