2004 dakota 4.7 4x4 4dr auto trans.
255/75r/16 mud tires

Looking to do some mods trying to avoid hurting my current truck or having to buy a bigger diesel truck. I do a lot of Towing sometimes both on and off road (mud tires no getting stuck). Sometimes more than what it should be able to handle but it does.

Looking to swap possibly to 410 gears maybe 4:56 gears. currently running stock 3.55.

Am I going to have to swap out my whole rear axle to a 9.25?
My sticker inside the glove box says its at 9.

Also am I going to have to change my front gear ratio being 4x4?it says it's a 205 millimeter.

Also thinking about doing some kind of an exhaust swap, any suggestions? better sound better performance those are the things I like.

I put this truck to its limits I'm afraid I'm going to break it unless i change something.

Currently getting 13 to 15 miles per gallon I was getting 12.5 until I put a soft tonneau cover on. And obviously the more I tow weight-wise the less mileage I get. Mileage is not necessarily an issue for me so I don't care if I lose a little bit.

Ive read from several people that they've actually seen an increase in their mileage when swaped to a 410 or the 456 gear.

Also I put twin air on.... i love it! Sounds super sexy almost like a turbo lol. I think it did give me a little increase in power. Although it might just be the sound it makes me feel that way.


Yes i pulled this. Had to bring it down to 35 miles per hour on the steep hills to keep it under 3000 RPMs but on the straightaways no problem.

 

Also rebuilt the engine at 101000 Miles currently has 128000 miles

 

count the bolts on the diff. cover, 10 bolts = Chrysler 8.25 and 12 bolts=Chrysler 9.25 I can assure you its not a 9.0

 

Sweet so I counted the bolts on the rear diff I've got the 9.25 rear end. All I gotta do is go to ebay get the parts and thrown in. Is there any particular brand of Gears I should buy?

 

If you have the $$ great but changing the diff gears is not cheap about $800 and up shop price you could try finding a used 3.92 that may do ya at $300 up.

Options are nice swap out the rear axle assembly.

Changing gears DIY is not easy you can mess it up easy kind of a must have knowledge and special tools job.

 

You WILL need to change the gears in the front differential too. Otherwise you will never be able to use 4wd again.

 

Oh forgot about it being a 4x4 never owned one so I never think about that.

 

I have les swab tire center 2 blocks away that will do the actual work. Whatever it takes to get it done right. I just refuse to buy parts from them becuase they charge way too much for them.

As far as why the front has to be swapped too doesnt make since to me. Does it have something to do with the t-case?

What do i need for the front if i go 456 in the rear??

 

The front diff on a 4x4 has the same gearing as the rear. If you change the rear, you have to change the front as well, or never use your 4x4.

If you change just the rear gearing, the front wheels will rotate at a different rate than your rear wheels do when in 4wd.

 

Yup.

As TonyPilot says the front will TRY to rotate at a different rate than the rear - which CAN'T happen with all 4 wheels on dry ground.