I purchased a 2006 SuperCrew f150 in 2007 used. Before I purchased it I researched the gear ratios as I was going to be lifting it 6 inches and adding 35" tires. The only thing I could find was that the 3.73 gears came in them. After I lifted my truck, I realized it was EXTREMELY Sluggish... I expected a little sluggish but not this bad. After looking at my tab on my pumpkin it said 3.55 gears. I was like WTF!!! I need to change theses out and do a lot of towing through mountains with my travel trailor. I also do a lot of freeway driving during the week. Should I go with 4.10 gears??? I just need more power in the mountains. Any suggestions?

 

I would go with 4.56. 4.10 would be a decent medium since you drive it as your daily driver and on the highway, but I'd still say go with the 4.56 with 35" tires.

 

35's with 4.56, good to go

 

Wont 4.56 gears make me run higher rpms when on the freeway?

 

If you came with the stock 245/65 R17 tires and 3.55 gears you were at 1750rpm at 60mph. Now with 35s you're probably closer to 1480rpm (I used 315/70 R17 =34.4").
4.10 gears would put you back to 1710 rpm; which would be good for DD and highway use
4.56 gears would up it to 1900 rpm. But it would be a lot better for towing. You may lose some mpg, but thats the price we pay for fun

 

If you came with the stock 245/65 R17 tires and 3.55 gears you were at 1750rpm at 60mph. Now with 35s you're probably closer to 1480rpm (I used 315/70 R17 =34.4").
4.10 gears would put you back to 1710 rpm; which would be good for DD and highway use
4.56 gears would up it to 1900 rpm. But it would be a lot better for towing. You may lose some mpg, but thats the price we pay for fun

 

200 RPMS isnt going to even be noticable gas mileage difference. And you have an OD trans so the RPMS will be manageable once in Overdrive

Go with 4.56's take the stress off the trans. just my opinion

 

Just a quick question:

I have a 2006 FX4 i'm wondering what's the size of the rear diff and front diff? on my door stiker it says B6 which is 3.73 LS .

front: 9'' ? rear 8.8'' ? can't find any info regarding this

i'm looking to change to 4.56.

thanks!

 

if you have a 5.4L motor then you have a 9.75 rear end

if you have a 4.2-4.6L motor then you have a 8.8 rear end.

ALL IFS 97-09 front ends are 8.8r's make sure to get reverse cut gears

 

thanks 4.2 !

 

no problem. im gonna send you an email.

 

I know this is old, but what's a good company to get gears from? I was looking through 4wheelparts.com and found some 4.11's for like $180, but the reverse cut comes in 4.10? Is that a typo, or will that actually work? The manufactuer is G2.

http://www.4wheelparts.com/Drivetrai...5092&t_pl=2214

 

Randy's Ring and Pinion is pretty good and so is Richmond gears.
http://www.ringpinion.com/
http://www.richmondgear.com/

 

I'm going to be getting 35's soon too. I can only find these 4.11 gears. Which ones do I need if I wanted 4.10? What's the difference between the reverse cut and regular? Do I need both?

 

the front diff needs the 8.8 inch reverse cut. if you have a 5.4L motor, you need a 9.75" standard cut for the rear. if you have a 4.6L or 4.2L, you need a 8.8" standard cut rear. check out www.summitracing.com for some deals on gears. i hear yukon, precision and ford racing are good brands. i plan on getting ford racing when i do my swap. im not too sure about the 4.10 vs 4.11 thing.

if anyone else has some insight/ opinions on the subject, feel free to chime in.