Engine/Transmission (1998.5 - 2002) Late upshift

[Rusty_S]

I have a 98 1/2 3500 dually. The 1-2 shift has always been very low speed. I've always thought too low but at least it was always the same. Recently It started shifting into second about 2800 rpm. And this only happens right after I start and take off. After that it's fine. Also I've noticed I have to drive about an extra mile or so before it will shift into overdrive and then lock up the converter. And again just while it is cold.

My question is could it be the "governor pressure sensor/Trans temp. thermistor" If not what?

Also the truck only has 85,000 miles, has Amsoil fluid, and a triple clutch converter which I put in around 40,000 mi. I use for towing my 5th wheel and have never abused it in any way.

 

[georgej]

My truck would delay the shift into overdrive when it got in the twentys but I don't remember the delayed shift out of first. . Retired now so I get another cup of coffee and turn up the furnace:-laf