Alright...have a weird problem going on with my 2005 SXT. This happens occasionally, but today on my way home from work it was pretty scary. When I accelerate my speedometer starts to "bounce" meaning when Im going 20 or so it will drop down to zero, then back up to where it should be rapidly. It seems to do this right before it shifts, and prevents shifting. Seems like it helps to accelerate very slowly...anyway sometimes it does this for a few seconds before it decides to jump into the next gear, and other times it wont shift at all (usually 1st to 2nd) I have done a little research and heard of peoples speedometers failing completely, then not being able to shift out of 1st at all. This seems to be remedied by replacing the input/output speed sensor on the tranny.

Has anyone experienced this? Im thinking about just getting the 15 dollar part and replacing it myself to see what happens...worth a try I guess?

 

That is what I would do. A simple low-cost attempt to fix it at the most likely place it is occurring is not a bad way to go. I did that for my oil pressure sending unit. A new sensor cost $12 and about 1/2 hour to put on, and while it did not fix my problem, it was still a helluva lot cheaper then taking it and getting it diagnosed at a mechanic shop for $100 or more.

 

Well, replaced the output speed sensor, and still will not shift....Oh and the speedometer has stopped working entirely (this was before the sensor replacement) I really cant afford diagnostics on this thing right now....any ideas?...im thinking of replacing the input speed sensor too...