Hey guys, I am looking to instal lockers (front and rear) does anyone know what dif. (s) come stock on an 05 f-150 Fx4

 

Your truck has a 3.73 ratio limited slip rear (Ford 9.75" axle), and a open front (Ford 8.8" axle).

Your options for the rear are an ARB air locker, Eaton E-locker (electric), Detroit Locker, and I believe the Auburn ECTED (electric) Locker.

For the front, there are those I mentioned, plus a few more. There are alot more units available for the 8.8".

If you insist on using a locker in the front, (I wouldn't), and you plan on EVER driving on the road in 4wd, be sure to go with one you can "shut off." If this is an "off road only" truck, than it doesn't much matter.

My recommendation would be to put a Detoit Truetrac (gear-type limited slip) in the front, and whatever locker you want in the rear. That way, you can put up to 2 tires in the air, and at least 1, and sometimes 2 (depending on the situation) will be able to move you. If you read any of my posts, you'll see I'm a huge advocate of the Detroit True trac, and no, I don't work for them!!!

 

Thank you this is exactly what i was looking for

 

it may not be 3.73. mine has 3.55 limited slip. look on the rear differential cover for the tag and it will say

 

I thought the FX4 came standard with the 5.4 and 3.73 limited slip. Am I wrong?

 

All I know is I had to get the 3.73 LSD as an option on my FX2