DenverDave

I called several dealership service departments and got a range of answers to this question, before it occurred to me that the people in service departments who answer phones often know little about cars - they are there to book an appointment for you. Here's the question: On a 2018 F-150 without a rear locking differential is there anything that keeps the wheels from spinning freely when one wheel is on solid ground and one is on ice? Most newer cars apply brakes to the wheel that is spinning to force the other one to turn, but do trucks like the F-150 have this feature? The old 4x4 Fords I grew up driving were essentially two-wheel drive since only two wheels spun - one in front and one in the rear.

elptxjc

They're called LSDs, or Limited Slip Differentials. I was surprised not to see them offered on '18 F-150s. LDS is different from ELD (electronic locking differential), since with ELD, the differential is locked, meaning no tire slip at all (like a quad), so it has to be used in ice, mud, heavy snow, and such conditions that allow the outer wheel to slip, or your truck would make a horrible noise. With the 3.5EB and/or towing package, you get an ELD, but depends which one. On King Ranchs, you get the 3.27 with the EB, but on the Platinum, you get the 3.55. If you get the max towing package, you automatically get the 3.55. You can also order a differential as a stand alone option, I believe, but I haven't seen a single truck on a lot with it, so you'd have to order one. Hopefully somebody with more experience on that can chime in. Just wanted to share what I found out. Good luck.

kwbob

The f150 also applies the brakes to the spinning wheel. It is tied in with the traction control

tvsjr

If you don't have a locker, this is partially correct. Ford does some magic with the traction control to engage the brakes on one side when wheel-spin is detected, trying to mimic an LSD. The effectiveness of this is questionable.

Personally, I went 4WD with an ELD. With everything locked in, I know I have power to, at minimum, 3 wheels.

montanaman

Unless they decided to downsize them, your truck should have a 34 spline 9.75 differential.

IMO the best LSD for your truck, for all around use is the Eaton TrueTrac, and the part number is 913A477.

It's not cheap, over $500 for the differential, and another $300-$400 to have it installed, putting in new bearings and seals while you're in there.

How's it work? Park one tire on packed snow/ice, and one tire on the dry pavement, step on it, and there is no one-wheel-peel, it just goes.

On dry pavement, in a straight line, step on it, and both tires dig in and you go - two black marks.

Your truck does have traction control, where if a tire spins it'll apply a little brake to that tire, to start the power to the other wheel, and it goes with the LS like pretzels and beer.

Numerous threads on this - happy hunting.

Skyjockey

moparado

But its nowhere near fast enough. Rear right tire always seems to take the spinning abuse.
I've yet to see the traction control work on my truck though i've never been stuck in mud or snow where it probably was intended to work.
Its not a perfect system but i suppose better than nothing.
The elocker is great but its only good up to around 25 mph and needs to be unforgetably manually engaged.

Why Ford doesn't offer a LSD or even a Torsen rear diff is beyond me especially considering the lighter aluminum bed.
Ram and i think Chevy offers some form of a LSD.

GP-SE

I have the 8.8 diff with 3.55 gears and the E-Lock Diff. Even though traction control is supposed to apply the brake to the spinning wheel to allow differential action to take place it doesn't work that good. I've had to engage the E-Locker to get both wheels to spin.

Canon101

A little off topic but seems to be the place to qualify.
I do not have the E-Locker so essentially 1 wheel gets traction in the rear, I get that. What about the front end of these trucks? I can not use 4wd on dry pavement, if I do and turn, the tires scuff as if both are locked in (essentially mimicking a locked front diff). When in 4wd is the truck actually a 3wd as apposed to what I always thought a 2wd (1 front and 1 rear wheel)?

mikeinatlanta

Without a locked rear it is 2wd. The reason for the binding is due to different distance traveled front and rear. It doesn't matter that both have an open diff.