I have a 2006 F-150 XLT Crewcab 4X4 with 5.4 V8. I'm thinking about yukon 4.56 gears because I'm going to get a lift and 35's. I have 3.55 gears now and I know I need to regear. I just want to know exactly which gears to get? Which ones are compatable with my axles? What's the exact part (like 9" 31 spline or what)? My truck is all stock now

 

Check your door for your axle code, for example mine is H9 which means 3.55 gears with limited slip.

 

Your rear axle is a 9.75" and the front is an 8.8" reverse cut.

 

And how many spline are they?

 

Not sure, but I think 31. Someone will probably be along to verify. Might do a search on "spline".

 

34 spline is for the rear.

i got my gears from wayne at diffsonly.com give him a call and he can get you what you need.

 

wayne at diffsonly.com never knows what he is talking about. i called him about gearing recommendations for my 35's and he told me 5.13's should give me about 2100 rpm at highway speeds. i cant believe anyone would take his advice or make a purchase from him. str8tsix id consider getting your **** checked out or sending your junk back right away.

 

 

actually, the 34 spline axles came in the 04-05. In 06 they changed to the 35 spline.

 

well i guess ill find out if he shipped me the right gears when i get them put in. i didnt take his advice, i already knew what i wanted to run and those rpms would definitely be higher with 5.13's.

 

5.13's would be ideal.................for 37"+ tires........

 

Even with tires that big, a 5.4 doesn't need 5.13's unless you are building a dedicated offroader. Not too practical for the street or a DD.

With 35's and 4.56's, your rpm's in OD at 70 would be 2150. With 35's and 5.13's, at 2100 rpm you would only be doing 60.