What does it mean? and is there a big diff in the two? I have a 07 FX2 screw which I love but I notice on my window sticker that it says 3.55 limited slip diff. Being that he truck is a 2WD is this something that I should be concerned about? Even though its too late, lol.

 

If you have a 2wd limited slip is a BIG plus. Limited slip 'senses' when one wheel is slipping, and then 'locks' the two back wheels together so they both get power and will spin, instead of just one. Gives you much more traction.

Way cooler burnouts too You can leave two nice long black marks instead of one little pegleg black line lol.

 

LOL. So I take it that the 3.55 is cool. If it matters I have a V8 5.4

 

3.55 is a nice all around rear end gear ratio.
Compared to a 3.73 it isnt quite as peppy when you nail the gas, but it will lower you cruising speed RPMs.

A 3.73 rear end will be a little snappier feeling when you hit the gas, but you will also have a higher crusing speed RPM.

Honestly, there isnt THAT much of a difference between the two...

 

towing=3.73
cruising/justing looking good=3.55 for the slightly better fuel milage....

 

Even though I have the tow package on my 3.55?

 

I myself have the 2wd 5.4L with the 3.55 limited slip. right now im looking for a shop to install 4.10s.
I tow a boat on the weekends and a lawncare trailer during the week so I need a higher gear ratio and a buddy, while it is a dodge ram, has 4.10 gears and feels stronger towing.

so because i cant stand the thought of a dodge out towing me, I am taking the plunge and getting so 4.10 gears. if you would like in about a week or so ill tell you how its working out.

 

the 3.55 gear is a good gear for normal dialy driving and towing from time to time. If you plan to tow alot a 3.73 would have been a better choice. The limited slip is a big plus I had a open rear on my 2000 I have the limited slip on my 2005 the 3.55 gear was in both trucks.

 

I have 3.55s with 33" tires. I wish I had 3.73s. HOWEVER, with an FX2, I'd go with the 3.55 for the highway gear...

 

all the posts about gears concour... the 3.73's do just as well if not better in the fuel milage factor. Plus you get slightly better performance, and better towing. I would stay away from any thing below 3.73.

 

I will only be towing from time to time and when I do tow its just my ATV or my sportbike ( 400+lbs) on my open Trailer (290lbs). Remeber guys I have the FX2 if it makes a difference. What does the 3.73 do when towing that the 3.55 will not do?

 

The 3.73 can tow 9500 lb, the 3.55 can tow 8500 lb.

The 3.73 with 18's Max GCWR is 14500 lb, the 3.55 with 18's is 13500 lb.
The GCWR is the maximum combined weight of your loaded tow vehicle and the loaded trailer. (Gross Combination Weight Rating)

You will notice the trailer, while taking off or down shifting for a pass, more so with the 3.55s than the 3.73s.


See the 07 brochure.

http://www.fordvehicles.com/trucks/f150/brochures/

 

Go get aftermarket 4.11's atleast in there. I would actually go with 4.56's if your tires are 32" or bigger in diameter.

I went from 3.55's to 4.11's in my 5.4 3v regular cabbed and GAINED MPG and added a good amount of oomph to truck.

Dont fear the gear

 

YES!

 

What are 4.56's, 4.11's. I'm new to this truck stuff. I have the factory 20" rims that came on my truck.