My buddy wants to put my 3.73s into his 2011 ext cab 4wd. His truck is one of the dumb *** trucks that has 3.08 gears and 6L80e. 33s are soon to come, so he would like to upgrade. He has no intentions of modding or tuning the truck besides the 2.5" lift and tires.

Could he goto the dealer and ask them to reflash his ECM for the 3.73s on a 2011?? He just wants his speedometer to be corrected? His main concern is that HP tuners will void his powertrain warranty.

 

If the 3.73's were available as an option with his engine/trans combo, then GM should have a calibration for it.

 

hmmm I think 3.42s r the lowest gears avalible with a 5.3

 

Bingo.... so unless he want's 3.42's ( and even then I have my doubts), the dealership won't do squat. Well actually they will have no problem telling him over and over that his regear, tires and speedo flash voided his powertrain warranty...... Unless he is of the rare few like myself who has found the warranty to be a complete useless joke and not care anymore. If that be the case any tuner ( real or handheld) can set his speedometer for him.

 

Go to dealer tell them you need GT4 option added to vin. Dealer will have to call technical assistance tell them to change the axle ration option to GT4 they will charge the dealer 50 bucks to add it to his VIN. They will then simply reflash the PCM and he's good to go.

In the future should a pcm die or update be done everything will be correct because the GT4 3:73 was added to the VIN at factory level.

 

If he were to go to the dealer, who would he tell to get this done?

 

cool thanks man. I'll let him know.

 

service writer or if he can actually get to the tech who will do the job.

 

That's good to know, we weren't able to do that with the GMT800 trucks when I worked at the dealer.

 

It was a PITA for me to figure out tinkerin on my own **** but I finally found the right channels and TAC will get it done.