Question About Replacing Rear Axle.

[Iceman83]

I currently have a 4.10 conventional rear end. Can I use a locking diff, or does it have to be replaced by a conventional one?

 

[Carguy3J]

I currently have a 4.10 conventional rear end. Can I use a locking diff, or does it have to be replaced by a conventional one?

First, when you say locking diff, I'm assuming you mean the factory liimited slip ("posi") rear, which is not a true locking diff.

If you are talking about swapping the whole rear, with a replacement; no problem with that, as long as the gear ratio is the same (4.10).

You can also swap the carrier or "pig" as some call it with one with a limited slip. However, used ring gears and pinions should stya together, and not mix-and-match. So, you'll either need to use swap the pinion gear with the one from the donor vehicle, or swap your ring gear onto the replacement carrier.
Unless you're pinion is coming out anyway, for bearings,etc..., it will be MUCH easier to swap ring gears. This will also keep you pretty close on setup, such as backlash, and your gear tooth pattern, since you wouldn't be changing your actual gears. However, every carrier could be cast/machined sightly different, so you may still need to "setup" the whole deal to make it right.

 

[Doubt Incarnate]

I think he's wanting to make sure his axle housing is compatible with other carriers. They basicaly have to be the same shape and size other wise they wouldnt be able to fit in the 8.8 housing. i swapped in a trac-loc last year, just make sure you have alternative transportation or a press handy. i had to bum rides to a shop to drop off the old and new carrier to get the ring gears swapped around.

Only thing you might have to worry about is sometimes manufatures used slightly different carriers based on the final drive ratio, i dont know if ford did this in the explorers, im sure someone can prove or disprove this and say once and for all if this is something you need to keep in mind. lets say you found an 8.8 trac-loc with 3.23 gears or whatever, the bolt holes on the 4.10 ring gear may not line up, the 3.23 could be slightly smaller. i used a unit from a f-150 with 3.55 fdr and had no issues with my 4.10 gear fitting it.