Hey guys, I have an 05 F150 that I am trying to tell if its limited slip or not. I searched and have found several threads about checking the door sticker. Problem is, the door sticker on my truck is unreadable. I have a build sheet but that is confusing, it starts talking about anti spin traction control, and later in the sheet it lists the axle as "less anti spin"

Anyway I pulled some numbers off of the axle tags on the diff itself. The one on the drivers side simply says "USE 75W140 SYNTHETIC ONLY". The bottom row of numbers on the passenger side tag reads "55 88 5B09". I know it is a 3:55 ratio, and I assume not limited slip by the lack of "L" or "LS" in the code. Can anyone confirm? Thanks in advance.

 

If it is limited slip it will have "LS" on the tag. Is it a super-crew?

 

Yes its a super crew with the 4.6 liter. I didnt see anywhere on either tag where LS would fit.

 

Look at your tag again. (this is on the axle, right?)

"55 88 5B09" should probably read "3 55 88 5B09".

If limited slip, it will read "3L55 88 5809".

 

OK go to your drivers side door and look for the tag with all the manufacturers information on. Now look along the bottom of it and see where it reads Axle. Then just match your code up below and that is how you know what axle you have in your truck.


18 - 3.08 Non Slip
19 - 3.55 Non Slip
B6 - 3.73 Limited Slip
H9 - 3.55 Limited Slip

Here is a link to a site with the tag information broken out for you too.

Ford Door Sticker Decoder .: Articles

 

That would make things so easy, but heres the problem:
This is what my door tag looks like:


Unless I can find differently before my next change, when I take the cover back off I will try to bend the tag straight and see what else is there. In the meantime, I changed the fluid and added the friction modifier for LS diffs, if my diff is indeed open, will this hurt anything for the next 30-50k?

 

That's the tag on the door pillar, not the door itself, isn't it? That tag is usually yellow and gives the payload for your specific truck.
Is the tag on the door (the part that is swinging, about to hit ya in the knee) also illegible?

 

I don't believe the SuperCrews came with the "LS" option.

 

That is the tag on the B pillar. There are not tags on the door that I have seen. The wife got back home about an hour ago and I went back under the truck and flattened the tag out. I could see the numbers clearly as: 3 55 88 5B09. Half of the 3 was cut off, so it could have been an "8" lol. No where did I see anything that even resembles an "L".

I guess this means its open, which is fine, I dont do any kind of wheeling or anything so I wont miss (and havent) it. Will that additive be okay in there or will I have to drain out that horribly overpriced RP? (I swear Im going to cry just thinking about it)