I have a 2002 f150 5.4 fx4. I want regear it but I don't know what's in it. I looked at the tag on the drivers side door the axle code is h9. What I have researched everyone says 3.55 limited slip my question is does the fx4 package make it different? Because some threads I have read say that it's 3.73. Any advice would help.

 

If it says H9, it's 3.55 limited slip. You can confirm by crawling under and reading the actual axle tag, it should say 3L55 on it somewhere.

 

Thank you very much do you mind if I ask you a couple of questions

 

That's what your thread is for - asking questions! Ask away, the only dumb question is the one that isn't asked. You will get better help asking in the thread instead of by private message.

 

Yup. H9 is 3.55 Limited Slip. Same thing that is in my 01 Screw. I am also going to be regearing next summer. I am going to go with 4.56's to go with the 33 inch tires I am buying in the spring. Don't worry about asking questions, we were all new once!! I'm still learning plenty of things everyday!

 

At some point I am also planning on going with 4.56 with my current 33's

 

I appreciate all of your help should I go with 4.10 or 4.56 I have 35s on my truck now would go down to 33s but they look to small on my truck cause I have 3in body lift and 3 in suspension lift even my 35s look small to me. Anyway way off topic my bad. But yea im stuck between 4.10s n 4.56 and I plan on doin it myself just wonderin if there's any difference between the 2 on install. Once again thank yall.

 

Bama,
Go 4.56 I'm running 33's on my 02 Screw Fx4 and had 3.55's for the longest. I never went to 35's b/c i knew it was to much tire for the stock 3.55 limited slip. With 4.56's and the 33's i'm running 2100rpm @ 70mph on the interstate, with 35's you'll probably be a bit lower.

 

Definately 4.56. If you tow at all you will love having them. I thought about 4.10s myself, but I don't want to be undergeared for when I tow my race car or my dads boat.

 

I don't tow a lot just when somebody needs my help but I do play in mud and sand a lot as of right now mud im good in but sand I struggle in. Plus im super sluggish.

 

Yeah, the 4.56s will make the truck more snappy and help it get up to speed quicker and easier.

 

Awesome 4.56 it will be then thanks for your help. kno the best place to buy em?

 

Wayne @ diffsonly.com. Tell him that you heard about them on f150online and they will cut you a good deal. I was quoted around $800 for both front and rear ring and pinions, both install kits, and rear axle bearings and seals. That was without shipping.

 

Oh awesome thank you so much

 

No problem, keep me posted on how the install goes and fill me in on the drivability changes and how you like them. I won't be doing mine until next year as I am beginning to build my chopper.