hmmm I thought all FX4's were 3.73 LS? You sure yours is true.. Is there a place to enter the VIN and find out for sure?

 

Mine is cloth not leather. My console is not a full one also, and my gauges do not say FX4... I do got the stickers.. skid plates, the rear axle is 3.73... but then again mine is a supercrew cab

 

Please don't confuse me on the limited slip or locking diff's on the F150's. I know u can lock the rear diff on the 09+ FX4's but do the 04+ have a e locker like the Chevy's w/ the Eaton G80 locking diff. So are the diffs the same on a F150 4x4 and Fx4's????

 

Mine is the same as yours except it's a supercab. Also My '02 FX4 had 3.55's, but my '04 FX4 has 3.73's

 

Is your 04 missing the full center console, leather interior, and FX4 instrument cluster?

My truck seems to have the differential locked in. If I floor it from a dead stop it will light the tires leaving two identical spin marks from both rear tires. My ranger had a limited slip rear-axle. One would spin, for a second or two before the other one kicked in.

 

The pressure on limited slip clutch packs differs greatly. Your 04 doesn't have a locker from the factory. It would have been added aftermarket.

The LS in my '06 FX4 is also pretty aggressive as I assume that the pressure on the clutch pack plates is high. My truck will also break both tires loose if I want, but again, I don't have a locker.
If your rear diff was locked, then your truck would be a bear to turn (truely locked axles always want to go straight -- think professional drag cars, fully locked there), additionally the inside wheel on the turn would chirp every time you made a turn, fast or slow, light or heavy throttle input.

 

yeah my buddy has front and rear lockers on his 78 460 bronco on 44 in tires and they howl every time he turns in a parking lot.

 

F-150 Cat, I have a red supercab 2004 FX4 with leather, tow package, 35,000 miles, bedliner, bull bar, hood shield, 3.73 axle, 18 inch aluminum wheels and with only 35,000 miles in case you are looking. I'm in Nashville,TN

 

I have an 04 Fx4 with 3.55LS. It now has 127k on the clock and the packs are useless. Looking to do a rebuild kit and add an electronic locker. I may put an air locker so I can have the excuse to put ON BOARD AIR. My suggestion is to buy what is in your financial means. You should try to get a dealer to print out what it came with from the factory. Some of them have heavy duty parts not advertised.

I have the window sticker..mine is a TRUE FX4. All FX4s are build to the market that orders them.
I have....sport cloth,column shifter,s/d plates,3.55gears,18''wheels,ESOF4x4,60/40 rear bench, single seat/center seat.

 

im wondering if the 3.55ls fx4 option was maybe 04 only??? everyone who said they have the fx4 and 3.55's are in 04 years.

BatteriesNotINCL you say the packs are useless, how lond did they last and do do lots of burnouts to kill them?? im looking at buying a posi (even one removed from an fx4) but i dont want to pay the $300 to install it if its almost worn out or will wear fast because i have 35's and love to do burnouts way to much.lol

what is in the back of a raptor?? (if anyone knows)

 

The Raptor is running 4:10s with an electronic locker.

 

is it the same diff? i think we run 9.75 from what i remember

 

From the little bit I could locate, it does appear that the Raptor also uses the 9.75" rear that our F150s use.

 

cool thanks for the help, i will have to keep my eye out on ebay for one from a wrecked raptor and maybe get lucky

 

You want the electronic locker and 4.10s that bad? Why not get new gears and a selectable locker from an aftermarket company?