Overdrive not working

Good afternoon.

What condition was the fluid when you changed it?

Is there any codes set in the system?

Do you mean fourth gear or converter lock up?

Roy

https://www.2carpros.com/articles/automatic-transmission-problems

I do not have overdrive or fourth gear.
At seventy mph rpm is 3,000. Fluid was nasty but new filter a bottle of Lucas and high millage fluid did not change still no fourth gear. I was told could possibly be a sensor or switch or something external that plugs in.

Hello,

This sounds like an input shaft speed sensor is going out but we should run the cdoes first.

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

Here is the location of the sensor (below) Please let us know what you find.

Cheers, Ken