I have an '06 King Ranch Expedition and just recently got a tune-up. Engine was running great after, but now I started having tranny issues this morning. Running at 50-60 on level highway, I noticed the tach skyrocketing and seen that it wouldn't stay in OD. Had to push the OD OFF switch just to get it home..

Checked fluid in tranny and it was full. This is a rebuilt tranny that I had installed a lil over a year ago.

Should I change the fluid and filter? Could this be causing that alone?

What about the transfer case fluid level? What is the best way to check it? I've read that the best way to fill is thru a pump system of some sort, but how do you check it?

Also will tranny issues show up as a code when your check engine light comes on? Is there a way to diagnose these issues? Any help is greatly appreciated!!

 

Sorry for the delay with the reply. My transmission did the same thing and to be honest I'm still working on getting it fixed. Normally with this issue it would just be your overdrive servo is malfunctioning or damaged. There is a spring clip that holds the servo into its place and if that spring clip breaks for some reason you will lose overdrive. Also the pin on the servo could be letting fluid bypass losing pressure and not letting the servo operate correctly. The only way to find out if this is your problem is to drop the transmission pan and the valve body visually inspect. There is a thread on this site I do believe it is call expedition transmission= dead. In that thread it explains where to look and basically exactly what you have to do. If that is not your problem then you would want to look at your shift solenoids. The shift solenoids will be attached to the valve body. I hope this helps. If you have any questions that I have not answered feel free to ask. I do not rebuild transmissions for a living but I have a little experience with what you are working with and if I don't know the answer I do have the technical manual for your transmission and can look it up. Good luck.

 

Thanks for the reply. That was some very helpful information. As for the delay, late is better than never..lol..