Truck & Trans Running Differantly.....

[icanfixall]

Well last week I had the alternater problem and disconnected both batteries when I removed and installed the voltage regulater and alternater. My shop told me years ago doing it that way I wont have any currant surges into the new parts. I have burned up new voltage regulaters doing this before when things were still hot. So now things are running fine but there seems to be better shifts and lockups now. Even the motor seems to run stronger. I did install a 35 tooth gear in the speedo replacing the 39 tooth GV sent me. The 39 was the wrong gear. So maybe did this smaller gear change something? I realize the speedo has a small generater on the cable that helps tell the cpu and the trans when and how hard to shift but is this really what I feel... Maybe its driving that big 4500 Duramax around 3000 miles and now I'm driving something easier...

 

[suv7734]

ONE of the signals used by the transmission control unit is the VSS (Vehicle Speed Sensor) which is a signal from the speedometer, therefore changing the speedometer drive gear will cause a difference in how the trans operates. Think of it like this; if your truck is running at a certain RPM, with a certain throttle position at a certain speed if the speed changes (different speedo gear) and the rest of the parameters remain the same the TCU will think 'things' are different and react accordingly. (Firmer shifts in general at higher RPM or 'more' throttle position in relation to the speed of the vehicle.)

 

[icanfixall]

Thats really what I thought too. The shifts are firmer but not really higher in rpm. I do like what I'm feeling. Its like I found some new horsepower somewhere. Tis a good feeling...

 

[94johnh]

Had this happen to me when the batt's arr disconected the computer in the transmision gets reset .It takes a week or so to learn how you drive again something called "adaptive something or other " mode.

john