i got a 02 f150 fx4 that sits on 35's. the guy that owned it before me had put the lift and tires on but never had gears installed. just got it back from the shop with fresh bearings, seals, and 4.56's fron and rear. lovin it!

just wanted to get on here and spread my joy haha. i do need to calibrate the speedometer something fierce though.

 

Why are you "lovin it" ?

Just curious because I'm thinking about upgrading gears as well but people keep telling me no. What benefits are you getting?

Thanks,
Rob

 

if its going to be your everyday i dont really suggest 4.56. id go 4.10 with 35s. buuuut reason im loving it is the insane low end torque gain. before oli could hardly brake torque i ad now it spins if i mash it from dead stop or even goin 5-10mph. lot less stress on the whole drive train and tranny is shifting much smoother now. yet to see the mpg difference but im sure it will be less. if you do go 4.56 your top end will be cut dramatically. top now is about 75 or lil more.

 

My 4.6 '01 was capable of 15-16mpg highway with 35's and 4.56's if I stayed out of it.

 

From the insane amount of reading I have done on this forum 4.56 gears are ideal for 35's. Gas mileage, power, and ease of driving all accounted for. You want the final gear ration as close to stock or lower.

Kudos to the OP for doing it right.

 

should have went with 4.88's

 

ty! also an easy way to tell the gearing it should be around is to look at tire-gear size chart. if you google i theres one for every speed tranny and ratio!

 

I agree with the 4.56 and 35s as this was truly close to factory setting with little better torque response.

Here is the link to a chart I used

http://www.4lo.com/calc/geartire.php

 

OP...what's your RPM cruising at 70+ on the highway?

 

Mine runs about 2900 without overdrive and about 2350 with overdrive on.

 

Oh cool, I was a little concern about rpms and top speed when the OP said he doesn't recommend 4.56 for a daily driver. My truck is my only vehicle and I'm running 35s so I want to regear to regain power for daily driving.

 

Unless you do a lot of freeway driving definitely 4.56. People say 4.56 put you back to stock but they don't, it puts you deeper then stock. Which imo is necessary in these trucks as they are overheated from factory if u have the 3.55s I spin about 1900 at 60.

 

Here is a chart I made up when I was trying to decide on gears. It is for 285s and 315s ( almost 35). It also takes into account squish.

 

interesting, i do right at 2K at 60mph with 4.88s

 

Interesting stuff.

Alright, so I have an 08' 2wd with 3.55's. It's a daily driver but I'm thinking about getting a lift and putting 35"'s on. I don't do any towing at all. I was planning on going with 4.10's, but y'all are saying 4.56 would be the best/better option?