How can I find out if the rear axle on a used 1999 f-150 has limited slip?

Thanks,
Mike

 

Get the code off the axle tag on the rear diff. There should be 2 tags, 1 is the oil weight and the other is the axle ID tag that says what size, gears, and carrier.

 

Another way to do it is to jack the truck up so both rear wheels are off the ground. Put the transmission in neutral and spin one wheel. If they both spin in the same direction, you've got LS. If they spin in opposite directions, you've got the standard rear end.

 

.....or

you could open the driver's door and look on the sticker.
The last row of data has a two-digit code under the word AXLE

19 = 3.55 NON LS
18 = 3.08 NON LS
H9 = 3.55 LS
B6 = 3.73 LS

 

Raol my daughter lives 5 miles from Yorktown. The door code wouldn't work on my truck as they made a slight error when I ordered the truck. They forgot the limited slip that was my most stressed option. They tried to give me several hundred dollars more off the truck which I told them they had a real pretty island blue and gold truck on stock now. The sales manager had them install the limited slip on the truck. But the rear axle tag will always tell you what you have. Glenn Taylor.