overdrive problem

[jasonmsu1]

Does anyone know what would cause my 97 explorer to stop going into overdrive after the truch reaches operating temperature?

 

[IZwack]

valve body?

 

[Glacier991]

Generally the loss of a gear is often indicative of a pressure loss in the system when that gear is commanded. It could be that once the temp is higher clearances change due to expansion, coupled with thinner ATF and ya got a pressure loss. I'd drop the pan and carefully retorque the VB and see if that solves it, if not, I'd consider removing the valve body and replacing the gaskets. It COULD be a solenoid as well. That may be a little tougher to find without a transmission tester. I'd also have it checked for codes. Those are first thoughts. (and with the VB out you might want to rebuild it with a shift kit - see the 5R55E valve body rebuild diary on here)

 

[TPLYNCH]

Is the engine running hot? Does it idle high when you are at operating temp?