montanaman

Hi Guys -

I did a long-winded post about upgrading my rear differential to a TrueTrac, and I've been talking for a couple of years about putting a TrueTrac in the front.

First, the TrueTrac in the rear is still awesome - so why wouldn't a LS (Limited Slip) in the front 'punkin be double-awesome? After all, the Jeeps with the lockers in the front are unstoppable.

So I finally decided to bite.

I pored over the catalogs, and while I found TrueTrac's for the Ford 8.8 axle, which my 2011 F150 has, they didn't show one for the front, only rear.

So I called up Eaton, and talked to two of their people.

They agreed that I could bolt the TrueTrac in, and it would work, but they did not recommend it. Why? Because they are engineered to reliably put horsepower to the ground, mainly in the one direction. I asked them if I couldn't reverse the gears in it, and they told me if I wasn't an expert I'd never get it right.

Now what? I didn't want any kind of clutch-based LS, because I didn't want the preload to make my advance-trac steering work any harder than it already does, and I don't want to rebuild it - ever - yes, call me spoiled.

Then I thought about the 2012 -2014 Raptor, which had mechanical LS in them from the factory. So I searched the web, and couldn't find a single person who had upgraded their XLT.

So I learned that the RAPTOR differential is made by Torsen, was mechanical, no clutches. It looked like the T2 or T2R I see in the speed catalogs.

So I called the engineer at Torsen. He told me the T2R was out, because it had too much preload. I would hate steering it in 4WD. I asked him if the RAPTOR carrier was simply a T2, and he told me no. I learned that they only make that one for Ford, and that they changed both the Bias, the preload, and it is set up for the front end, to dig, last, and be easy to live with.

So I decided to get a RAPTOR carrier, and axles if necessary, and make my front end a poor-mans RAPTOR, minus the Fox racing suspension and 2" lift.

So I shopped Ford dealers for the lowest price, found one willing to discount it to $600 and change, ordered it, bought new carrier bearings, 3 Qts of boring old dinosaur GL-5 Gear Oil, and I splurged and bought a nice chrome cover, with a drain plug, so I can change the oil out every few years easy.

I dropped it off at my favorite shop, and they put it together, and 'voila, it fits, and works. It's not a cheap mod, I'll have $1100 in it, but I'm interested to see how it performs on snow, dirt, and gravel. I'll put up a couple of pics, and I'll update this this weekend, when I give it a workout.


The most important part!



Solid - looks unbreakable.



Bearings and races.



Gotta have a drain.

JLTD

Sounds cool, be interested to see how it does.

One question before you put it in 4wd: The Raptor has 4.10 gears. Did you swap your rear end gears to 4.10 also? If not you will blow up your transfer case, if it engages at all.

kersh04

Nice, thanks for doing all that work. I was thinking about putting an LS in the front of mine as well. I look forward to seeing how it performs for you.

montanaman

I kept the 3.55 gears, I just re-used the 'old' gears on the new carrier, and when I twisted the ****, the transfer case shifted to 4WD the same as it always has. There is absolutely no change in steering wheel feel, and this weekend I intend to go out to some dirt/rock, stop, and punch it doing some wheel turning, and see just how well both tires dig.

I think it's unlikely I'll break that transfer case because last year when I dropped the forklift off the edge of the blacktop, I put the nylon tow strap on it, and stepped on it, and I had so much pulling power there that my rear differential locked so tight I had to speed up to 10 mph in 1st, and then let off the gas quick to get it to disengage. I can't see torquing that transfer case that hard under any terrain, given the tire slip.

montanaman

I can't wait to go driving off the pavement.

marshallr

The issue that I think is most likely to cause problems is the chain inside the transfer case. When cornering in 4X4, even in many off road situations where traction is good it puts strain on the chain. The damage is gradual and cumulative. You can go a long time without realizing you are doing any damage. Until the chain stretches enough that it starts slipping on the gears.

I'd think a LS in the front would accelerate the wear. To me an open front diff with the ability to lock it as needed would be a better option. But I hope it works out for you.

jp360cj

$1100 isn't bad for that upgrade, and getting the "right" diff I think was well worth the extra $100 or so over the Trutrac, especially if the Torsen works just as well. Interested to hear how is does compared to Ford's traction control system.

montanaman

That's the one thing I cannot figure out - with the rear end, the TrueTrac and the factory traction control go together like pretzels and beer, but does the XLT use the factory traction control on the front wheels, or just the back?

JLTD

Figured you did it right, I read elsewhere where someone put different gears front and rear...and Mayhem ensued.

montanaman

[QUOTE=JLTD;5252197] Figured you did it right, I read elsewhere where someone put different gears front and rear...and Mayhem ensued.




That would indeed be a bad thing !