4L80E LETTING OFF PEDDLE TO SHIFT (ONLY WHEN COLD?)

[BC_Silverado]

1993 GMC 2500 4x4 4L80E 65000 Miles.

My work truck which I only use 2 times a week, a couple hours a day seems to have a shifting issue in the morning or after sitting for a couple hours.

With truck placed in Overdrive from the start:

Shifts 1st to 2nd great.

2nd to Drive/3rd (I have to let off for it to shift or it will stay revved)

Drive to Over Drive/4th (Same thing I have to left off the gas peddle for it to shift or it will stay revved)

After doing this for a couple miles are maybe a couple intersections she is good to go for the rest of the drive.

It has tons of power and not slipping at all. I installed a drain plug for quick oil changes.

Going to start with Draining the pan, Changing filter.

Is there anything I can check or change with the pan off is my BIG Question? Or is this just a live with it till I need a rebuild?

[Supreme Pizza]

Check the transmission fluid level. Check the kick-down linkage, if it has that. 

[BC_Silverado]

So nothing is wrong with the truck/tranny.

 

The truck is used for lawn care. I pull a 18ft trailer loaded with equipment around town for only 50-60 miles per week. From client to client. Then it just sits. Rarely gets into 4th/Overdrive. Never goes over literally 40mph all week. 

 

Checked the trans-fluid. Bright red and full. I decided to finally unhook the trailer and take it for a good run out of town for a day.

 

Transmission now shifts like new. I'm going to every couple weeks unhook and take her for a good drive. Spending $40 on fuel in the 454 is better then replacing the tranny.

Edited August 3, 2018 by BC_Silverado