fx4 ring and pinion set up?

[Raider50]

With my off road tires going much over about 110 is out the question, so on that note I figured a new ring and pinion setup to lower my gears would be in order. The truck is kinda heavy at some where around 6k and even with the roush on there it isnt just amazingly quick, its more real fast from 50-90ish. A mostly simple solution would be to get a new lower ratio right? I would like more quickness off the line but also a degree of drivability out on the highway. would a 4.10 be more apropraite or a 4.56 or somthing like that. Also who makes a really quality kit for a 4x4? Well thanks once again guys

[FTE Ken]

What size are the tires? A 4.10 about 10% more engine revs per tire revolution, whereas the 4.56 is about 18% more. I'd take the original tire size, divide it by the new size and whichever it comes closest to go with it.

[Ryan50hrl]

What size tires are you running, also how big of lift are you looking to get?

[Raider50]

the tires are in no way huge. I will need to look when i go out side, its not that they are that big it is that the a sort of low profile type offroad tire for the most part. The are on 20in by 12in wide rims and the truck only has a 2in leveling kit on it i know that. Because of that combo its hard to find a tire that fits and can go through snow mud and what not. The local tire shop just told me that they were not rated for more than about 110, no problem as of now because its still limted to 100. I was just thinking a new lower gear set up would be awesome paired with a troyer tune. With the wides on it i would think with the gears i could about break my neck on a launch. sorry for any confusion on having big meats on there, and thanks again guys

[tylus]

if you want a hard breaking launch off the line, you'll need the 4.56 gears.


Your FX4 already has the 3.73 gears...and going to 4.10 will be a difference, but not worth the ~$2,000 for the front/rear axle install.


also, since you seem to have bigger tires than OEM, the 4.56 gears will help you regain your lost performance.


IMO, it's a 4.56 or nothing swap. That will make your truck a tire shredding low end monster when coupled with the Supercharger...If I ever have another $2k laying around, I'm slapping some 4.56 gears into there

[Raider50]

the only thing i would like to know is how it would go at 70-80 on the highway with the 4.56's in it. My tires are only 32in so im not sure if it would be to low with the 4.56's on it.

[tylus]

your tach would be about 2,200 to 2,400 for 70 mph with 4.56 gears and 32" tires

a 35" tire will put you about 2,000 rpm at 65-70 mph with 4.56 gears


so it's a best of both worlds IMO. the deep gears offset your bigger tires, and you get one heck of a performance boost down low. I currently run about 1750-1800 at 70 mph with my 3.73 set. So an extra 200-300 RPM will only lose me about 1 mpg


I can handle losing 1 mpg highway for the performance...not to mention, alot of the 6" lifted/35" tire guys report gaining city MPG after swapping in 4.56 gears

[Ryan50hrl]

Originally Posted by Raider50

The are on 20in by 12in wide rims

Do you need a small crane to lift those suckers???

[Raider50]

Originally Posted by Ryan50hrl

Do you need a small crane to lift those suckers???

nah, thats what my 18 inch cannons are for, liftin the tires