Rear locker vs 4L

[Expedition Dave]

What's funny is the only two options I truly wanted, I got: FX4 and HD tow package.

And while I have never bothered with anything less, the 3.73s sure make this thing quite quick on its feet, and if you feed her 91+ octane, even more so.

If they offered 4.10s, would I take 'em? Only if I towed on the the 9K edge or this thing came with 33-34 inch tires, stock LOL!

 

[Anerbe]

I personally find benefit of rear lockers vs. 4L, although each have their benefits. The con's don't make sense, as both can be deactivated.

Brake modulation differentials works when you don't need high torque - slippery relatively flat roads, or you have an overabundance of torque available (McLaren uses brake diffs). Your available power will split between the braked low traction wheel and the wheel with traction (you only get up to 50% of the power) since the car is simulating a resistance with brakes on the low traction side to equal the resistance on the traction side.

If you're doing some major climb off roading, pulling a heavy load over uneven/slippery terrain, or any application where you cannot afford to run at 50% power to a tractive side, locking diffs are key. Being 100% locked between the rear wheels, either corner uses the full power of 100% up to the traction available, with no slip sensing / reactions.

Rear lockers with 4wd makes the car essentially 3 fully time driven wheels, without brake modulation. 4L alone is still open diff between each axle, so there are scenarios where you can still struggle. In an instance of the right side in an icy ditch, left side high on pavement, 4wd open diffs will act like a 2wd vehicle. You will get 0% power to the left side without brake modulation, and 50% power to the total left side, 25%/25% each front left and rear left with brake modulation. In the same scenario with ELRD, 4wd and brake modulation, you should be getting a total of up to 75% power to the left side, as you don't waste 25% to the right rear, therefore left rear gets 50%, front left gets 25%. These scenarios assume that the traction available between front and rear left is equal, and the center diff is not redistributing power between front and rear.

 

[Bo Simmons]

Armin, curious what options you desire on the Limited that are not available in the XLT with the FX4 package? We are based in Georgia but plan a move out west to a Mtn town in the future, so I purchased the XLT with the FX4 package. I'd like to have added the variable cruise control but otherwise very happy what i have for the price point. Also thanks for the post it helped me learn a bit more.

 

[Calidad]

FX4 would be fine, except I'm just not sold yet on the fixed running boards, plus the mandatory moonroof on the Limited.

But you all have now convinced me I should not worry about the 3.73 axel. So in the end it probably will come down to what price I can get, and indeed negotiate some better tires.

There are much steeper discounts on the higher priced models btw.

The platinums don’t sell well due to their sticker scaring people away. My platinum cost me $500 more than a Limited the same dealer was trying to sell me with far less incentive to deal.
I got 12k off msrp on my platinum

 

[Armin]

@Bo Simmons the non-fixed running boards, folding side mirrors, forward sensors and the a bit nicer interior. It is all a matter of taste of course.

In essence the Limited 300 package is what I'd like, but if the price is good I may even do the Stealth package, despite that moonroof. Ever since I had this expensive non-warranty claimable leaking sliding roof window (for which fortunately Ford waived the cost almost completely) my appetite for the roof-window has gone to "dont use - dont care" to "rather not". But that Stealth package does look nice ...

 

[JExpedition07]

I’m confused what this threads meaning is since usually both 4L and the locker are in the same packages. 4x4 is always superior to a locker alone, if it’s a 2WD with locker vs a 4x4 with open diffs the 4x4 will always be more capable. My dads F-250 with locker on only can’t do half the stuff it can do in 4 low with the locker off. Both together is the best.

 

[shane_th_ee]

I’m confused what this threads meaning is since usually both 4L and the locker are in the same packages. 4x4 is always superior to a locker alone, if it’s a 2WD with locker vs a 4x4 with open diffs the 4x4 will always be more capable. My dads F-250 with locker on only can’t do half the stuff it can do in 4 low with the locker off. Both together is the best.

For 2021, the 3.73 eLSD is now a stand alone option.

 

[Armin]

... and even worse, if you pick eLSD you cannot pick HD tow for some reason.

Since HD tow and FX4 are the only two options that give 4L in 2021, this means picking eLSD means no 4L unless you take FX4.

But taking FX4 limits you to XLT or Limited with 301A package. You want one of the other 3 packages with Limited, or want King Ranch or Platinum? Well, then no HD tow - and hence no 4L - for you when you select eLSD.

I'm assuming Ford did this based on its actual sales data, but it seems odd to me not just offering the eLSD on any 3.73 axel truck.

 

[shane_th_ee]

... and even worse, if you pick eLSD you cannot pick HD tow for some reason.

Since HD tow and FX4 are the only two options that give 4L in 2021, this means picking eLSD means no 4L unless you take FX4.

But taking FX4 limits you to XLT or Limited with 301A package. You want one of the other 3 packages with Limited, or want King Ranch or Platinum? Well, then no HD tow - and hence no 4L - for you when you select eLSD.

I'm assuming Ford did this based on its actual sales data, but it seems odd to me not just offering the eLSD on any 3.73 axel truck.

The eLSD is the 3.73 and is included in the HD tow and the FX4 packages. I think the fact that you can pick the eLSD and then pick the FX4 but not the HD tow is just an error on the configurator website. In other words, i don’t believe you can get 4L without also getting the eLSD.

 

[Armin]

I hope so, but doubt it:

- Selecting HD tow removes eLSD and visa versa.
- HD tow is cheaper than the eLSD which is illogical if HD tow is a super-set.
- eLSD is not mentioned in the HD tow detail description.

So that would be a logically consistent error

The fact you can select eLSD and then FX4 (which includes eLSD) is not an error actually. It deducts the eLSD separate $1100 price when you select FX4 (but as you must then take the 301A package the price still goes up, cloaking this perhaps unless you watch the exact dollar amounts).

UPDATE/EDIT: Actually indeed it is an error. Looking at some actual window stickers, you can get HD tow with also taking eLSD.

In fact I could not find a single car without eLSD when HD tow was present. If indeed so, then the website error is that HD tow and eLSD are listed as mutually exclusive, when in fact they should probbaly work like the FX4 package where HD tow should be priced at 1100+795.