Just put a lift and tires on my 02QC 4x4 and would like to change my gear ratio to try and get some "energy" back. I do not know much about this so please humor me. Do I need to change the gear ratio in both my front and rear end since it a 4x4? Or can I just change out the rear end? I do not use my 4x4 much but do not want to mess anything up.

 

First of all, yes you do need to change both the front and rear gears. A little about your mods would help also. What gear ratio do you have now? What size tires are you running? Most likely, if you change your gears, you'll going with one of the following popular ratios.... 3.92, 4.10, or 4.56. I wouldn't run a 4.56 unless you have 35" tires or larger. 4.10 is usually an all around good ratio, as well as 3.92. Many of the stock trucks have 3.92 in them already though.

 

I believe I have 3.55's. I am running a 35x12.50/R20 currently. Seems like I am lugging a lot. I have also buying a reprogrammer for Superchip, dual exhaust and a Cold air intake. Looking for the most bang for my buck.

 

I don't have a 4x4, but if you're running 35's with the 3.55's, I personally would make new gears my first priority. I have the 3.92's gears on my 2wd, and I too am running 35" tires; I can definately notice a difference. From what I understand you do have to regear both the front an back differentials at the same time and I've heard prices ranging from $1000 to $2000 to regear a 4x4. I think the large price range depends on who's doing the work and maybe the part of the country that you live in. Just my opinion.

 

i got 315 35 24 tires on my ram ruffly 33s and right now im getting 4.10s put in mine had 3.55

 

I went from 3.55 to 4.56 with a 29.75" tall tire and would have it no other way... I do have new tires going on this week that are 32" tall but 4.56's with the 29.75" tall tire is not that bad at all 2700RPM@70MPH. When I get the 32" tall tires It will be 2500RPM@70MPH... If I had 35" tall tires it would be 2290RPM@70MPH.... Now I have a 2002 with a .75 overdrive... those of you who have 2003+ will have the .67 overdrive and your RPMs will be MUCH lower.... transmission overdrive gear = tire hight means EVERYTHING

With the 45RFE (.75 OD) 2002 Rams
35"@70MPH with 4.56's and .75 OD = 2290 RPMS
32"@70MPH with 4.56's and .75 OD = 2500 RPMS

With the 545RFE (.67 OD) 2003+ Rams
35"@70MPH with 4.56's and .67 OD = 2049 RPMS
32"@70MPH with 4.56's and .67 OD = 2241 RPMS

SPEED SAFE, AIR RAM

 

AIR RAM, any clue what it does in the 1/4? aft the mods? I have the daytona and was thinking of going with the 456 gears, also how's your gas in the city with a lite foot, I dont mean a GRANNY foot, just a lite foot.

 

My fuel economey has INCREASED with the 4.56's, due to the fact that it takes less throttle to do the same work. On the flip side they launch the truck like a sling shot. Its like all pros and no cons.. unless you drive 80MPH everywhere you go... thats when the MPG start to go down.

SPEED SAFE

 

I am eagerly awaiting Hank_L's 15,000 word post about fuel economy and the modern story of the combustion engine, piston design, and tire pressure lol.

 

[sm=funnypostabove.gif] LOL !!!!!