200 help high shift when warm

[kodidogs]

I have a 200 4r tranny and was wondering why when it is cold it will shift with no problem but after driving for a while it starts to want to go to 3500 4000 rpm before it shifts. Seems to downshift hard to when warmed up.
I have had the pan off to see if the valve was stuck but it seems fine. Adjusted the TV cable and have checked to make sure there is enough tranny fluid in there. So now what?
BTW the gauge reads about 150* when this starts to happen. Really does not start to read higher unless I'm in traffic and moving slowly and the engine temp is going up too.
Also Hi new to posting here but been doing a whole lot of reading.

 

[Donniejr81]

Welcome.

IMHO your problem sounds like a pressure issue. If the tranny fluid is cooler it will be thicker, thus holding higher pressure. As it warms up, it thins out lowering the pressure. If you have access to a tranny line pressure gauge, install it just to see where you stand. In P, N, OD, or D the minimum pressure should be around 90 if my memory serves correctly.

Do you hear any type of faint whining when your car is running? That could indicate a failing tranny pump.

Have you ever had your tranny totally flushed? Fluid color and viscosity can tell lots.

In all of my automatic vehicles I have always used Lucas Transmission additive...and will continue using it in everything I have...I can tell a difference.

 

[chris718]

If youd like further assistance we need full pressure reading hot and cold with minimum and max tv so we can see what is going on.

 

[mitchell.cox1]

I have the same problem with mine trying to figure it out, was thinking about flushing the transmission, does it help?