In a few weeks ill be putting Motive 3.42 gears in the rear, replacing the 3.23's that are in there now. The rear was howling pretty good so I decided to give the rear an overhaul and there was no difference in price between the 3.23's and 3.42's so I opted for the slightly better performance, although im not expecting much of a difference. Anyways, any need for a computer tune to get the car to think everything is normal?

 

Your MPH will be off but the computer wont function any differently

 

You mean other than the speedo being off? Probably not, those ratios are pretty close.

 

Alright, thats what I figured, just something small. The computer will be geting re-tuned later in the summer, itll just be a few weeks itll be off. I was mainly worried about the trans freaking out or something.

 

At a true 60MPH, your speedo will indicate 63.5MPH. For every 1000 actual miles that you drive, your odometer will show 1,059 miles driven.

 

A computer tune will fix that though, correct?

 

Yeah, re-program for the correct gear ratio and everything will be 100% .

Since you're not switching drastically between ratios, I think you'll be ok, but I've heard that when going extreme (say from 2.73's up to 3.73's/4.10's) that the computer (which controls both upshifts and downshifts) should be re-programmed before ragging on the car, because the tranny may have odd shifts/shift-points, because the speed ramps up much quicker, and the computer may allow shifts to occur when/where they shouldn't . You can still DRIVE the car (I have myself) but from what I've heard, it's not recommended to drive it too aggressively, which I never have until I've re-programmed for the gears.

Like I said though, since you're only going from 3.23 --> 3.42, that's probably not a big deal ... try it out and see .