Hi all and TIA for all responses. I own a 1997 F250 4WD (under 8500 GVW) with 7-lug wheels (yes, 7 on 150mm bolt circle). This truck is a heavy-duty 1/2 ton F150 upgraded to 3/4 ton specs. This truck has the same 8.8 in. front differential as the F150 4WD. I'm planning to upgrade the rear 10.25 in. Sterling axle to the FRPP M4204-TT312 differential for better traction. I would also like to upgrade the front 8.8 in. differential to a torque biasing type like the TrueTrack or Torsen. Has anyone done this? My truck has automatic locking front hubs so I want to make sure what I'm planning will work. Thats why I'm posting this, to find out from other who tried this what works and what doesn't. Thanks, CobraRGuy (Perry)

 

I wouldn't lock a front diff.

 

So do you want to "lock" it or put a limited slip in it?
Tru-Tracks and Torsens are limited slips.

 

As I stated in my original post, I would like to put a Tru-Track or Torsen differential in front. This truck will see some occasions where the added traction in front will come in handy. My '95 Cobra R has a Torsen T-2R Racemaster differential in back and I love it on road courses. It's quiet, strong, and provides superior traction and differential action (which on a 600HP road course car is necessary). My assumption is the front 8.8 in diffs are 28-spline. Is this correct? I'd love to hear from anyone who has put a positive traction differential in the front of their F150 4WD. Thanks, Perry

 

Tru-Tracks and Torsens are actually "Torque Biasing" differentials. "Limited Slip" typically refers to either a cone or clutch type differential. Perhaps using "Locking" in my subject line was confusing. My apologies for that.

 

I don't think that anyone has installed one yet. I want to do the same thing, but I'm unsure about a limited slip in the front and how it would engage in corners. I am looking at e-lockers or ox-lockers, so I can choose when to lock my wheels together.

 

A selectable locker would be better in front. It will allow you to use 4x4 on the street and still be able to steer. A selectable can be turned off so you can turn with out skidding.

 

So would a limited slip or torque biasing diff.

 

I agree to that. Thy act like open diff tell a set deference is sensed between the 2 tiers then it sends more torque to the one slipping.
On thing thou, Torsion type is not recommended for tiers more that 33" tall, If i remember correctly.

Hears a like for more info.
http://en.wikipedia.org/wiki/Torsen

 

A limited slip will act like a locker unless you have enough friction/traction to overcome the preload in the clutches or gears in the differential. A biased sensing diff will still lock both wheels together. On a slippery street you may encounter a situation that will lock both front axles together and you will loose control. When this happens there is no way to unlock the axles. A selectable locker will act as an open differential but allow you to lock both wheels when needed.