I need help with finding a rear differenical.
I'm driving a 2004 4.0L V6 Edge. I've been customizing my truck which is adding extra weight to the rear end, and I'm wanting more torque and grip to the rear end to be able to handle the customizations. I also live in a town where winters can be hard and having a locking differenical will give me piece of mind.
I've done a lot of looking around and I'm having a hard time finding a certain type of differenical. I'm looking for a torsen selectable locking differenical. I'm not interested in a elocker, air locker, Detroit, or LSD. I think I've found two that might do the job, but the description of the differenical doesn't say wether it is a LSD, Detroit, or selectable. Can someone educate me?

Ford 8.8, 31-Spline, – T-2R

Ford Ranger FX4 Replacement Differential

 

I am not aware of any Torsen differentials that are selectable. I am not sure there are even any selectable locker available for our Rangers anymore. If you don't want an e-locker or air locker there is not much left even in the used market for a selectable. I know there are some cable selectable locker but I don't know if anyone made them for Rangers.

Torsen and Detroit-Eaton Truetrac are very similar gear type LSDs, nether are selectable.

 

Both are also for the 31-spline FX4 - Level II/Explorer rear axle. Your stock rear is only 28-spline.

 

Ahh, so I need to find a 28-spline instead of a 31.

 

I looked up some information that I found when I was looking for something for my front differential. Here is a link for OX Lockers and it does appear they have a selectable locker for a 28 spline Ranger rear differential. It is not cheap but you can choose from manual, electric or air shift. Ford 8.8 2.73 & UP, 28 SPLINE - OX USA.

Here is another link that shows a Detroit -Eaton Truetrac for a 28 spline Ranger rear differential. https://www.jegs.com/i/Detroit-TrueT...2A562/10002/-1 It is less expensive but is not a locker. It is a gear type LSD like Torsen.

I have both Torsen and Truetrac on different vehicles. I like them both but have heard that the Truetrac is not as durable as the Torsen. Both have held up well for me. I originally wanted a selectable locker for the front of my 02 FX4 but they just are not available ready to install as is and it would have taken a lot of work to use what is available. I decided to go with the Torsen front differential to work with the Torsen rear differential and I am very happy with that decision. I do some pretty rough off-road trips and they have come through for everything I have gotten into.

The Torsen and Truetrac act almost like lockers when accelerating. Using the brakes a little also help to make them work better when one tire has no traction.