I bought this truck 3rd hand a year ago and knew nothing about these trucks except that they are as solid as a rock. It has three gauges and runs pretty good. Bought and ran AE and with Rich's (Tugly's) help analyzed the data and concluded that the PCM has been tuned, no chip and it is pretty hot.

Several experienced people told me that it is not a good tune for towing and I will need to stay alert and manage it a little when towing. Being the sole driver I am OK with that. But it seems to me that the truck knows when it is experiencing more load and adjusts the shifts accordingly. Under no load it shifts into OD at around 40 MPH. Pulling my beaver tail trailer that number climbs to more like 50 MPH. And it is so sensitive that if I lock the front hubs (they're manual) and leave the switch alone it hits OD at about 45 MPH.

Does this sound unusual, or is that how they all work when a chip is added?

 

It sounds like it is doing exactly (give or take a few mph) the same thing my same year truck has done since I chipped it with a T/S 6 pos chip.


It seems to sense the drag of the front driveline when hubs are in lock and towing my dovetail the OD holds out just a bit longer.


I like the transition of the shifts and it seems logical that the added drag in any event pushes the gearing up a hair to compensate.


Denny

 

The PCM looks at the Throttle Position Sensor, RPM, and Speed in this situation. When you have the front end locked, there is a little more drag and you dig deeper into the floor to get the desired acceleration. It's the heavier foot that "adjusts" your fueling/shift strategy more than anything else.