Originally Posted by Camaro Eater
Just got new gears for the 2010 mustang, 4.10s from 3.31 and went with the posi rear as well...Is there a "break in" period for the gears? I certain amount of miles must be driven in order to properly be able to use the gears? I have heard a million different things, any help would be great!! Also how the hell do I change the speedo using my SCT tuner? Can I do it manually or do I have to call SCT or AM?? If I can do it with my handheld on my own, then how? Thanks everyone! You guys always point me in the exact right direction!!
I was told a few hundred miles for a break in period. I have also heard go to the track and tear into it. But its better safe than sorry.
It depends if they left the tune open or not. When you select the custom tune, there should be a user changes option. It should let you select the gear ratio. Thats only if they left the tune open. They give free tunes for life so if you cant change it yourself, they'll do it for free. Good luck.