I just got a Powerboost 4x4 SCrew. I have the electronic rear locker, and am trying to figure out if I want to do a Truetrac or another E-locker in the front. My old explorer has front and rear Truetracs and I have zero complaints about its road manners, so I do not have a strong preference either way. The E-locker seems like it would be more complex to set up, as I would like to wire it to the factory switch for the rear locker so that both engage at once, but with the benefit that all four wheels are locked together. The Truetrac has the benefit of indestructible simplicity and my understanding is that the Raptor uses a Truetrac in the front. If Ford has already done the testing and I can buy an essentially factory sponsored part, that would tip the balance. I would love to hear from Raptor owners about how they drive, any issues (I assume none), and most importantly where to find the part for the '21.

Any input is appreciated!

 

Great question and hope you get some good feedback.
If memory serves me correctly, Ford uses a Torsen on the front.
I have the standard open differential on my '19, but am definitely interested on the feedback you get.
Best of luck!

 

Update: I bought the diff from Ford Performance, working on finding the correct rebuild kit (the vendors are suggesting that the 8.8" Reverse IFS '21 is different from '20, working to clarify that). Will let you know if I can find a dealer willing to install it, which will determine if I keep the stock diff cover or add an aftermarket at the same time (asking aFe if theirs will fit or not). Hopefully this benefits Raptor owners who didn't spring for the Torsen but decide that they want it after the fact. I would advise getting it based upon my experience with an Eaton TrueTrac in the front of a different car, but I'll update that opinion with a before and after once it is installed.

Raptor Torsen

 

If you call Eaton they will tell you not to put a Truetrac in the front because it's designed to put most of it's
torque in one direction. The front carrier in the Raptor was specifically built for the weight, and steering
load of a F150 and is worth the money. #doneitdidit

 

That may be true, but my experience has been exactly the opposite of that. The Raptor forum is full of guys complaining about torque steer, but I've never once experienced that with my Truetracs even with 4A on all the time. I was concerned about that issue when I first got it installed, but can honestly say that on pavement, you'd never know that it's not an open diff unless told. The rear also chirps far less than it did with the old Ford LSD (I DETEST Ford LSDs after being stuck one too many times because "limited slip" meant "one wheel spins at 500 RPM while the one with traction sits motionless").

Updates: Yukon says that the rebuild kits between 2009+ Ford 8.8" IFS Reverse diffs and 2021 are the same. Ford dealers CAN install the Raptor torsen, but they need a special tool to reset the caster/camber which only bigger dealerships seem to have. Closest dealer in Houston says they can, but wants me to leave my truck sitting in their lot untouched for "4-5 weeks" while their transmission guys deal with the backlog in order to even get on the queue. I tried to negotiate on getting a service date to bring the truck in when they are free, but they refused to consider that. If anyone has ideas there, I'm all ears.

 

Check out this post from 5 years ago - a real zombie thread.

https://www.f150forum.com/f38/limite...-front-377699/

 

Thanks for finding that! Great info. The bias ratio can vary a LOT in torsens, and absolutely makes a difference. I went with the Ford Peformance part (it actually says "FoMoCo" on it with no Eaton branding at all), but on the old Exploder I had an Eaton Truetrac Super 30 in front. It is entirely possible that I got REALLY lucky with the bias ratio in that torsen being front diff appropriate, but I didn't notice the thing unless I deliberately hung one wheel on soft earth and one on pavement to check it.

The ongoing issue is that the big dealers are still telling me to let my truck sit on their lots for a solid 2 months before they'll work on it instead of giving me an appointment. The issue is that the cost of flying to work and renting a car is going to eclipse the cost of the labor, which I expect to be $2-3k, and this behavior just seems disrespectful of my time and money. It HAS TO be done by a big dealer because they have to adjust the steering castor/camber (the steering linkage is almost touching the front diff cover when assembled) after replacing the front diff, and only big dealers have the machine to do so. I'm trying to wait until the line is hopefully 1 month instead of 2, but that may be a pipe dream. I'll update everyone on how it goes once it's done, and it seems like a pretty cool mod for folks who want to go offroad.

I did get the Ford Performance rear diff cover installed, and I think that it looks really good (also makes it really easy to change the fluid).