Here's my question.
I have a 2006 F150 FX4. My understanding is that the front diff is a reverse 8.8". Is this a 28 spline or 31?
I have my eyes on a Torsen limited slip from a Ranger FX4 level 2, which had a 31 spline 8.8 rear axle.

The rear 8.8 is a C clip axle, but I'm unaware of how the IFS 8.8 axles are retained.
So does a limited slip that is designed for a rear axle 8.8 also work in the IFS 8.8?

If the torsen doesn't work out I may also consider a used trac loc and rebuild it, if it works up front.

 

IIRC the front is a 28 spline, you could probably use a trac loc from most 89-92/93 rangers, explorers with the 4.0 and 8.8 combo if it had a LS, some mustangs are 28 spl 8.8"s as well.

 

Do some research. I'm not sure if a rear carrier will work in the front. The spider gears may be different. The dimensions could be different inside the front housing also. The front axle has CV joints that install different from a rear axle. That is something that I would be interested in finding out myself.
Let us know if it works.

 

Yeah I read today that it is 28 spline...
I also heard that it uses C-clips in the IFS application, but I'm not sure if I buy it yet. I'll have to look around for some diagrams, maybe talk to some gear shops or something.
Being a 28 spline, running 35's, I don't think I want a locker in there, even selectable.
I think a used trac-loc from a 28 spline 8.8 ranger and a rebuilt kit may be ideal for me...
I'll post whatever my findings are (if any, lol).

 

im fairly sure its the same method as the rear. the front uses a c-clip to hold the "inner shaft" inside the axle tube, the flange on that is where the cv bolts to, which is then held in place by a axle nut and the c-clip. the shift fork and such im not very clear on how to explain how that works. its more like a coupler.