Limited Slip | Ford Explorer Forums - Serious Explorations

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Limited Slip

December 9, 2009
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I am looking at getting a 2002 Mercury Mountaineer with the 4.0 AWD open diff 3.55. What is all needed to convert to the limited slip? Do I just need to get an 8.8 31 spline trac-loc carrier? Or is it something different for the independent rear?

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Why dont you just go for the locker and do it right?

Why dont you just go for the locker and do it right?

More money, less street-ability. This is going to be my daily driver I just want a nice upgrade. A locker is what 500+ ? New trac loc is right around 200.

What is needed something for an 8.8 and 31 spline???

with my '04 AWD 3.55s Opens, I have never needed a rear locker, or LSD, snow or ice. The AWD pumps power to the front all the time, therefore only 65% winds up in the rear, never really had any problems. Compared with my heep which has a full lock center xfr case open rears, the Ex is as good or better. You could look for a JY rear and if it has the Class III hitch it should be a LSD, you can also check the door code for L4 or D4 which should be LSD. For street use TruTrac would be the way to go.. . .i was quoted $1500 to regear F/R to 3.73 and add the TruTrac on the Ex.

I hate having open rear diffs.... I can get a brand new trac loc for 220. I have to open the case anyways I need to change some seals.

What I am trying to figure out do I just need a carrier for an 8.8 and 31 spline or is it something different? Also what does the front axle have?

as far as i know no one here has upgraded from an open to a Limited slip, its been straight to a locker. ALSO, im dont think anyone did the work themselfs. wish we could offer a little more help bud, but i dont think anyone has done this one yet, ya want some brownie points? be a guinee pig and do a write up with some pics when your done. Good luck and again, sorry we couldnt give some more help. have you checked with a drive line specialist?

It is ok I totally understand.

It is not that I don't know how to do it. It is I just need to know the spline count before I take it apart to order parts. Even if guys did go to lockers does anyone remember the spline count?

BTW it is an 8.8"

if that was all you needed to know yeah, its a 31 spline 8.8" :-).

Sweet, thanks guys. Now I can just got to a Mustang site and get differential parts.

Now here is another one, what about the front, is that the same?