I was at a junkyard for some interior parts recently and came across what looked like a 2001+ Ranger FX4. The interior and entire frontend was burnt but the rear was completely new. The exhuast wasn't even rusted yet. But I looked at the axle tag and it's a 4.10 Limited Slip 8.8. Right now on my 2wd edge I've got a 4.10 Non Limited slip 8.8. The junkyard wants 200 for the entire axle. Should I get it? And how hard would the swap be?

 

The swap would be bolt-in. Very simple for you. 200 for a complete rear axle is pretty good IMO. That's what I sold my 8.8 w/ 4.10s for. Make sure you get the parking brake cables and brake lines and such. If you are lucky, it will even be a 2002 FX4 and you'll luck out with the 31 spline axle and torsen limited slip. If the truck is an automatic, even better because the 2002 FX4 package with manual transmissions had a few problems with their torsen units and there was a recall on them. Good luck!

 

For $200...yeah that'd be a pretty good upgrade (if it is in fact an Fx4).
You can't buy an LSD for less than that and it's installed (well once you get the axle bolted up. Plus the additional strength of the 31 spline vs 28 spline.

 

I guess what we all need to know is, is it a 31spline Torsen, or a 28spline standard?

 

The opposite is true. All of the early 2002MY FX4 Torsen-equipped axles were the same but Ford only replaced the ones in the manuals because only the manual trucks had experienced premature failure of the Torsens. That leaves the early 2002 FX4 automatics with a big question mark, IMO.

If the axle has a purple tag, it is one of the replaced units and should be OK. If the truck was built after about Jan/Feb 2002, it should have the improved diff whether it is manual or automatic.

 

^^^ ABSOLUTELY!

If it's a 31 spline, you're going to need new u-bolts, and axle plate. If you get it for $200 complete with brakes and all, it's a good deal. The 31 spline axle tube is a 1/2 inch bigger diameter (3.25 inches vs. 2.75 inches) .

Now, if it's an unrecalled torsen LS, and you have a manual, it might not be a real good idea if you intend to thrash it.

An axle swap is easier than a diff swap, and the torsen isn't a clutch type (if that's what's in there) and doesn't wear out like a TracktionLock diff does.

If it's the 31 spline, you'll need the additional parts we mentioned before and DEFINITELY get the brakes since the backing plate and all are different from the 28 spline axle.

 

you have an open diff now so even if it only a 28 spline unit its still a good upgrade.