Gear change-reflash?

[Barton]

New here. I have a 2003 Silverado half ton, with a 4.8 and 3.42 rear gears. I am thinking of changing to 3.73 because I tow on occasion approx. 4000 lbs. If I towed more often I would consider 4.10. My truck tows my trailer well except in a stiff head wind. My question is as follows: do I need to reflash the computer? I have seen on the RV forum that some say it is needed and some say the computer reads the ring gear speed and that as long as the tire size stays the same the speedometer will be accurate. Thanks, Barton

[mjgjr72]

New here. I have a 2003 Silverado half ton, with a 4.8 and 3.42 rear gears. I am thinking of changing to 3.73 because I tow on occasion approx. 4000 lbs. If I towed more often I would consider 4.10. My truck tows my trailer well except in a stiff head wind. My question is as follows: do I need to reflash the computer? I have seen on the RV forum that some say it is needed and some say the computer reads the ring gear speed and that as long as the tire size stays the same the speedometer will be accurate. Thanks, Barton

 

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reflash for gear and or tire size changes

the computer reads the driveshaft speed off the trans tail, your speedometer will be off and also reads the whell speed off the front hubs so you abs light will come on due to the deference in the ft and rear readings

if its a 4x4 you need to change both the ft and rear gears at the same time

[Shotgun]

Yes you will need to re program for new gears which can be done with a hypertech programmer.The change to 3.73 isn't much and hardly worth the trouble or $. Are you running stock size tires?