Limited slip

[stevewallace]

I have a 2002 Expedition, ex NorCal cop car. It definitely has a limited slip diff, 3.31 ratio but the tag on the diff cover doesn't have an L between the 3.31. The tag on the door jamb doesn't show limited slip, either. The other tag on the diff cover says synthetic oil only. What's going on?

 

[GlennSullivan]

I have a 2002 Expedition, ex NorCal cop car. It definitely has a limited slip diff, 3.31 ratio but the tag on the diff cover doesn't have an L between the 3.31. The tag on the door jamb doesn't show limited slip, either. The other tag on the diff cover says synthetic oil only. What's going on?

What is the Code on the door jamb under axle?

Or you can jack up the rear and spin one wheel, if the other spins in the same direction it is limited slip, if it spins in the opposite direction it is an open differential. Don't know how long you have had it or how many miles are on it, but there is the possibility that the rear differential was changed sometime during its service life.