Want to change the gear ratio in my truck but know much about it. I have the 4.7 with tow package, 5 speed auto. trans., anti spin differential, 4x4.

First off I can't find anywhere that says what gear ratio I have now. Looked on window sticker, on rear axle and all body labels including the one in the glove box.

Do the 05-07 4.7's all have 9.25 gears? I see there are also 8.25 gears available, is that for the 3.7's?

I'm assuming my truck now has 3.55 ratio but not positive, I see 3.92's were also available.

Also being a 4x4, do I have to change gearing on the front axle?

I'm pretty sure I want to go with 4.10 gears but if my current ratio is 3.92 I may want to get the 4.56's. Any help would be much appreciated.

 

I am pretty sure all the 05-07s have the 9.25 rears and on your window sticker it should be right here...

WindowStickerNVGears.jpg

 

if you open up the glove box there is a sticker on the back of it that will tell you the ratio. i had the 3.55 and went to the 4.10 like truck much better know, but getting use to the new gearing was like learning how to drive again. every stop sign or traffic light i came off of the tires would break loose. forget about driving in the rain. know i need to put it in 4x4. yes you will need to change out both. my cost for everything was close to 1600.00 but worth it. if you have the 3.92 stick with it. forget the 4.56, motor wont be able to handle it. you will be so high in the rpm range you wont be able to drive on the highway.would be great around town.

 

Thanks for the info guys, I appreciate it.

lghtngblt02, not sure why but the ratio is not listed on my window sticker anywhere and half the sticker in the glove box is missing.

eric, were the 3.92's an option?

I'm pretty sure I have 3.55's but will check with the dealer to make sure. I did find out I have 9.25 gears by the differential cover, it's a 12 bolt cover and the 8.25's are 10 bolt, I'm assuming the front diff. also has to be 9.25.

Superdak, that's 1600.00 for the front and rear I'm guessing. Did you buy Motives, Yukons or something else? BTW, any numbers on the dyno yet?

 

Hmmm weird... I would try the build sheet then like Eric said, search the forum, someone posted a ink or an email address where you can contact dodge for it, it doesnt take them long either to reply to you with a build sheet

Eric howd you find out the lsd was deffective?

 

3.92's where mostly in the r/t's and made an option for the others

the 8 1/4 rear is floating around in the Dakota's so make sure you check a build sheet so you know for sure.