I bought my 94' F-150 new, but I'll be darn if I can remember if it had a limited slip rear end in it . It came with the trailer towing package and I know the gears are 3:55. The rear end tag reads:
S838F
3 55 88 4B22

I'm assuming the bottom line represents the 3:55 and 8.8" gears but the rest?

 

When i asked about how to read the door sticker, this is what i was told
"Axle Code on the driver's door sticker.

19 = 3.55 open
H9 = 3.55 LSD
26 = 3.73 open
B6 = 3.73 LSD
27 = 3.31 open
18 = 3.08 open
25 = 4.10 open
B5 = 4.10 LSD"

Mines a different generation then yours, but maybe itll help you out. You can always take it out in the rain and see if you can get one, or both tires to spin from a stand still
-Patrick

 

Sometimes it turns both and other times just the right side. If I'm straight and level in dirt it usually spins both. Straight and level on pavement it tends to just spin the right side.

 

S838F is the part number Ford's factory ordering parts system uses to order a complete rear axle. 3 55 indicates a 3.55 open axle. If it was a limited slip, it'd say 3L55 or 3L73, etc. 8 8 is an 8.8" axle. 975 is a 9.75" axle, and so on. 4B22 is some kinda internal coding used to identify the plant the axle was built at.

 

You can't really determine anything by that. Mine has limited slip and it doesn't work worth a crap. It works ok when i'm in mud but that's about it. Almost every vehicle will favor the right rear tire for spinning because of torque roll.

If you really need both of those tires to work for ya, get a locker.

 

I was afraid of that, thanks! Any idea what it would cost to add a limited slip?

 

Probably about the same price as a locker!!!

 

4B22...Manufactured Feb. 22nd 1994