I was just told by a local mechanic that if i change my gears in front I need to change the gears in back as well. Tell me if this is true. I could swear that some of you haven't. thx.

 

yup, you have to...you CAN change the back without changing the front, but then you can't put in 4wd...if you are going to put it in 4x4 then both of the gears have to be the same...

This is because the ratio (3.55, 3.73, etc...) stands for how many times the driveshaft is rotating per rotation of tire...(ex. 3.55 rotations of shaft/ one tire turn)...since the transfer case divides the power up assuming the same ratio, one gear in the transfer case would turn more times (if you went to 4.10s for ex.) than the other stock 3.55 one...this would break nears about everything in the t-case and would prolly mess up the tranny nicely too, along with axles, and ugh, its just messy. Change em both, or if you have to do one at a time, do the back and MAKE SURE AND NOT USE 4WD until you have the front in...good luck!