Hey guys i was thinking about putting gears in the truck. I have wanted to ever since i put 35's on the truck. I was thinking of 4.56 or 4.88 what do you guys think would be better. And kind of RPMs are you guys running at with these gears on a 35 tire. Thanks

 

4.10 for Fuel Economy/ Stock Performance (before 35's)
4.56 Towing/ More Power
4.88 Ready....Set....Launch (off the line acceleration)

I would do 4.56's if I were you. My rpms at 80 are 2500 with 35's at 4.88.

 

sounds good. The only reason i was thinking 4.88 was that i also wanted to put a lift kit on the truck with bigger tires. Just wondering if the 4.56 will be good enough

 

The 4.56's should be good. They will put you close to stock if you choose to go with 37's. Check out this site, it should help:

http://www.rocky-road.com/calculator.html

 

sounds good i think i am leaning towards the 4.56's. I was thinking of the yukon gears but was also thinking of the ford racing ones. I have a good experience with them on my mustangs. Let me know what experiences u guys have with them.

 

I have 35's with 4.56's and the combo is great.

 

x2
It was money well spent.

 

sounds good guys sounds like im gonna get the 4.56's but what do u all think of the ford racing set's. I get a break on the price because of where i work and would install them at work as well.

 

Still kind of waiting to see if anyone haws experienced the ford racing gears in there f-150

 

There's been people contemplating buying those gears but not sure if anyone has....

 

Hi, I just got a set of ford racing 4:56 gears installed in my 01 with 9.75" diff and they are noisy around 35-45mph. You get a constant hoot or howl at those speeds at cruise. Also above 80mph I get a vibration in the cab. They guy I had do my gears is susposed to be very knowldgeable and setting up rear ends is all he does. He said the pattern came out perfect and he couldent get it any better. He said the noise is a characteristic of the gear. I've searched online to see if other people had similar results and I found out that others too have had this same issue. They were saying something about checking the part number and make sure it dosent end in a specific letter, m i think it was. They said those sets are made for ford by motive and are noisy. I found this all out after I had my set ordered and installed, so I am just going to live with it. Hope this helps you out.

 

BS (sorry).
Assuming the gears are cut right (and really, they are for the most part but maybe you got a bunk set) any gear noise you get is the direct result of the setup.

I'd read/heard the same thing. Went to a reputable shop and I had zero noise.
And many others that I personally know will tell you the exact same thing.

You get what you pay for.
Go to a shop with a history of good installs.
There's a reason why they have satisfied customers.

I put 40K miles with a blower and towing heavy on my setup, And I had no diff whine. And there are lots of others who share my experience.

 

if you ever plan on goin to 37s id say 4.88. 35s id stick with 4.56

 

Yea, I figured the setup was the problem. From what I've read, motive gears require a different setup. The guy who installed mine probably used standard ford setup specs and proceadure.

 

I have 4.56 with 35" tires and love it. Got it done for about $2k. Im running at about 1900 RPM at 60MPH and around 2100 RPM at 70. One of my favorite mods that I have done.