Guys I need a bit of help, been lurking for a while but my first thread. Anyhow, picked up a '99 F150 Offroad. The door sticker is gone??? how can I figure out the rear axle ration/etc. I'm used to counting bolts and looking for stamped numbers. My rear end has 14 bolts and I don't see stamped anything. 5.4L and everything else is stock other than minor exhaust mods, CAI, 285's, and tweaked torsion keys

 

Can't answer, mumstheword.

Sorry, just had to.

Ok, jack up the rear, mark the drive shaft so you have a reference mark, and mark a spot on the ground and on a tire. Rotate the tire one complete rotation and cont the times the driveshaft turns. If it looks to be about 3 3/4, then you have a 3.73. If it looks like ablut 3 1/2, you have a 3.55. If it looks like about 3 1/3, you have a 3.33. You get the idea.

 

Look on the axle itself for a metal tag under one of the bolts. If you find it, post what it says.

In order for what Bluejay said to be accurate, you have to turn BOTH tires, and it has to be in neutral. If you have a limited slip, they will both turn when you turn one. I believe a LS was standard with the offroad package. My son-in-law has a 98 with the ORP and he has a 3.55 LS. However, his is a 4.6 with a 8.8" rear.

With 14 bolts and a 5.4, you may have the 7700 package and a 10.25" rear. Are the wheels 7 lug? If not, then it's a 9.75". I think the only possibilities with the ORP are 3.55, 3.73, or 4.10.

 

ditto for what glc said, about both tires must turn together due to the spider gears unless LS. if open, i would turn the d shaft and if the brakes arent dragging both tires should turn together with equal resistance., and a helper might come in handy to watch the tires and of course marking a spot w/white chalk works good. rossford