Upgrading my sport trac differential from open to locking or limited slip.
- Thread starter NH73
- Start date
jagdriver727
Site Donor 2021
8.8” LS from a ‘90s Explorer or Ranger. Both are fairly simple swaps; depending on configuration you may find one that’s a direct bolt-in. Worst case you are moving the spring perches and shock mounts a few inches.
Might want to look into a Eaton True Trac, The factory clutch type posi's are notorious for being worn smooth out from low preload on the side gears.
I saw that Eaton True Trac says not to use synthetic or friction modifier. That wouldn't be the deciding factor however. Could you use factory parts? What you think of the SPARTAN LOCKER SLF8831?
I Second the true trac. The Eaton fluid recommendation has been debated quite a bit, mine has Delvac 1 in it and does very well.
Ive heard good things about the Spartan locker but if you have a pinion noise as alluded to in the other thread, you might as well put a whole new differential rather than an lunchbox locker.
Ive heard good things about the Spartan locker but if you have a pinion noise as alluded to in the other thread, you might as well put a whole new differential rather than an lunchbox locker.
Delvac 1 75w90?
Affirmative ...
Synthetic lube is okay, I'm running Redline 75w90NS with my True Trac & it performs very well. Just don't run any LS additive of lube with LS additive, Mobil Delvac 1 is also a good recommendation.
Don't have any experience with the Spartan Locker, But any locker than fits in a OE open carrier is going to have drawbacks.
Torsen out of an FX4 Level II Ranger if you can find one.
How soon do they wear out or how much is this a problem? Yeah, I understand it all depend how someone uses their vehicle. The reason I ask is because the vehicle is already 17 years old, doing about 5000 miles a year and hardly works heavily. If the OEM works just as good as True Trac, when it works, then I might opt to use OEM if it is much cheaper.
In that case......The OE units are rebuildable. Then you have Cobra "S-Springs" to increase pre-load. I like Torque Biasing posi's like the True-Trac & Torsen over Clutch Type & Cone Type posi's. Personnel preference of coarse.
They're pretty much shot at 100,000 usually.....But alot of straight line driving can prolong their life significantly. They're not difficult to tear down & inspect the clutches & side gears.
They're pretty much shot at 100,000 usually.....But alot of straight line driving can prolong their life significantly. They're not difficult to tear down & inspect the clutches & side gears.
Couldn't agree more!! I got Torsen T-2s in both my Ford 8.8" axles and I absolutely love it.
Another vote for Eaton TrueTrac or Torsen. If not identical I think they are very similar in design. The price of a TrueTrac is the same or less than the cost of a rebuild kit for the OEM limited slip and you will never have to rebuild it. The Eaton recommendation not to use synthetic lube is controversial and they may have changed their recommendation. I use Delvac 1 in mine.
And Motorsport (AKA: SVO, Ford Racing, FRPP) offers a kit with Carbon Fibre clutches.
Agree.
FWIW the Factory Five / Cobra Replica crew seems to have come to the conclusion that the Torsen T2 has less bias than a True Trac and a T2R has more. I had some difficulty ascertaining the exact bias of them all... but did not go so far as to contact each manufacturer.
My True Trac seems to have pretty high bias, but it is a 9" and i'm told they vary with application.
Another vote for Eaton TrueTrac or Torsen. I have one, an Eaton TrueTrac, in my B3000 RWD and it makes it a lot better on snow/ice/gravel. Hands down the best thing I have done to that vehicle. Smooth, quiet, seamless. I have Chevron 90W-140 mineral oil in it.
