So i talked to 4 wheel parts yesterday and told them that i wanted to change my gears and put in a LSD he told me to go with the 4.56 gears since im going to be going to a 35" tire and lifting it in the future. I also told him that i read on this forum that after the gear change that i would have to get the truck reflashed or reprogramed so the ECU knows what gears are in it. He told me that, that only needs to happen to have the speedometer adjusted correctly.

Is that true?
Will this be alright or should i not go with that low of a gear??
And what kind of MPG will i be getting at 75-80 MPH???

 

true, it only needs it for the the speedo/odo, but seeing as that is also what your mileage is driven off of, along with a lot of other things, i think i'd have it flashed. you could also go the programmer route- would give you a few extra hp, too. just make sure you get one that does gear and tire size change calibrations

 

well see there is the thing, there isnt one out for the 09 yet

 

Man I wish they could make up their mind! I went to my local 4 Wheel Parts here in Dallas and they told me not to do the gears untill I could re-program because the shift points under load needed to be changed. I did not think this was right but who am I to disagree. I say change them and let us know if it performs well, if so I will be right behind you!

 

yeah well i dont want to be the guy who spends $1,700 on something that might not work right

Any more input?

 

im doing 4.56's very soon.

 

how soon is very soon?

and have you gotten the same kind of answers as i did??

 

someone on this forum stated that the computer did not need a reflash due to the speed sensor not being affected by the gear ratio change?????

I NEEEEED 4:10's in my 4.7 like yesterday. Anyone w/ some info?

 

I asked the dodge mechanic online. He confirmed that the speed sensor is not affected by the gear change.

 

sweet, i might be getting them before the end june