I need some help here. I have an 05 fx4 and I am running 33s. I am going to lift it 4" pretty soon. I want to re-gear and a buddy told me 4.10s would be good. I think my truck has 3.73s right now. Would 4.10s make a differance that I can feel? Could I go lower or is that bad? How low can I go? Also, any idea about the cost? I heard its about a grand. Any help will help! Also, should I look for a certain brand of gear?

Thanks!

 

"The look" is always a personal thing, but when you lift it 4", those 33's are going to look a bit small. You might be tempted to go to 35's at that time and that would put you looking for 4.56's (or so). I wouldn't do the gear swap until you're settled on the other factors that influence the outcome. I bought my truck on 33's with a 3" lift and replaced them with 35's. I'm now waiting on 4.56's to come in so I can have the swap done. $1500 is enough money to make you want to get it right the frst time.

 

Do you think 35s will rub any with a 4"? Also will it be bad to swap in the 4.56 gears while I am still running the 33s?

 

I only have a 3" lift and mine don't rub at all. I did completely remove the very bottom fascia trim (the spoiler attached at the bottom of the fascia that the fog lights are in). They also stopped rubbing the frame and sway bar since I put on wheels with the proper backspacing.

As far as your gears go, how long will you have to drive with 4.56's before the 35's go on? If it's only a few weeks and/or you don't do much or any highway driving I'd say you will be fine.

 

how is the truck now with 33's and 3.73s? and will you have to change the carrier if you go to a gear as low as 4.56. i know when i had my chevy if i went lower than 4.10 i had to change the carriers .but on the other hand 4.56's would really bring the truck to life too.
if the truck gets up and goes decent now i might just go with a st of 4.10's myself but thats my opinion

 

There are no carrier breaks for the 9.75. You can slap whatever gears you can find in there without changing anything.

 

Get the gears--you wont regret it. I have 285/65/18's (32.8") BFG tires with the Donahoe 0-3" adjustable coil over. I had 4:10s put in and I love the difference it made. I paid $1150 with a bit of a discount. 33's would look a bit small under a 4" lift. If you go to 35's take your gears down to 4:56. Remember how much these trucks weigh, my 04 weighs 6200 lbs or so. Thats a lot of truck to pull around. It will save your tranny in the long run.

Check my photos in my album for tire size. Just click that little camera thing on the right side.

 

If I were you I would lift it six inches and put it on 35's. But if you were to go with a four inch 35's would clear fine. For the gearing go with 4:56's. Running the 4:56's with your 33's for a while won't hurt anything.

 

Thanks guys,

Im about to order the 4.56 gears right now. The reason I only want a 4" is because I use the bed quite abit and usually load all the gear (fishing and hunting) alone. Other than that I would love to take it up to six. Does anyone know of any other 4" tahn the Rancho? Has anyone heard anything negative about the Rancho?

 

I'm going to 4.56 gears. I'm wondering which brand to get. Yukon, Ford, Precision, etc. As long as they are premium gears, are they all about the same? I was going to go with Detroit lockers front and rear, but I have just about convinced myself to put an ARB airlocker in the rear and leave the front open. If I want, I can always add a locker to the front. Any comments? It is a wheeler, daily driver, and boat puller.

 

I have never heard anything negative about Rancho's lift.

 

I have 4.56 gears and 315/70/17 BFG ATKO tires that measure out to 34.5" diameter. My SOP assessment is I have more gear now than when I had 3.73 gears with factory tires. Keep in mind though, your hwy mileage will be greatly effected. I don't worry about gas mileage as I figured I'd be keeping the oil companies in business buying a 4wd F150 anyhow. I'm not too sure but I don't think there are 4.10 gears that will fit your truck; I could be wrong...

 

what about changing gears from 3.73 to 4.56? i got a 05 f150 fw4 5.4 S cab stock tires. can i feel the difference?

 

You can change to 4.10's or 4.56's, the only thing it will affect is the speedo and your gas mileage. If your thinking about putting 35's on then go with the 4.56's, you'll thank yourself later. As for putting the locker in the front, you might want to think twice about that. Detroit tru-trac is a very good limited slip that will work very well in the front and the rear, in fact I'm just waiting for the parts to come in so I can put them in my truck. Correct me if I'm wrong, but your truck has a CAD (Center axle disconnect) and the locker would make the driveshaft turn all the time, even in 2WD, but with the tru-trac you won't have that problem. I know this was long, but I hope it helps.

 

Check this out....

http://www.4lo.com/calc/geartable.htm