Looking at the option of a 4.30 axle ratio and an FX4 package and I would go from a limited slip? to a electronic locking axle? What does that mean?

Dammit Jim I'm a photographer not a truck mechanic......

Thanks

 

Limited slip= rear wheels *TRY* to rotate at the same speed under *most* conditions.
Locking differential= both rear wheel are locked together and *WILL* rotate at the same speed under *all* conditions. I.E. there will be NO differential action what so ever. And with electronic locking, you just pull the 4WD selector outward, and voila!!! Your diff is locked, and when you push the 4WD selector back inward.......you now have full differential action, the rears can rotate at different speeds as needed for cornering, parking, etc.
Hope I made this as clear as mud for you!!

 

select 4WD I will have locked rear wheels as long as I am in 4wd or will they lock when I lose traction in one? Does the 3.73 have the same feature? Maybe I read it wrong but it seemed I would not get that electronic locking in 3.73 just 4.30. Ugh this stuff is confusing 1st time buying a big truck so not up on some of this stuff. Thanks all!

 

Did someone call my name?

The electronic rear differential will ONLY lock when you choose to lock it by pulling on the dial (where you engage 4x4). I have this on my F-350 SRW and it's the way I prefer.

If you're looking at the higher axle ratios then you're looking at the DRW, correct?

 

Non-locking differential- one wheel on ice and one on tar, only the one on ice will spin which means you don't move.

locking diffenential- one wheel on ice and one on tar, the one on tar will spin just as much as the one in ice which means you will keep moving


both wheels are locked together with the locker versus the one with the least traction spinning with the open differential

 

By selecting 4WD, you have 4WD with full differential action in both differentials. ONE wheel on each end *can* spin, while the opposite wheel at each end remains stationary......you are stuck....even in 4WD. Now, with e-locker, you pull the 4WD **** outward, thus locking the rear diff. BOTH REAR WHEELS WILL ROTATE AT THE SAME SPEED. Now, if the rear with traction has *enough* traction, you are no longer stuck. The e-locker only locks the REAR diff, so it is possible to still spin only one front, and spin both rears.

As a side note, with my HEEP, I had e-lockers front AND rear!! It took a hell of a lot to stop it, but one had better have it pointed the direction you wanted to go because there wasn’t much turning when all locked up!!!!

 

OP. Here is a video that might help you figure things out.

 

Open diff and limited slip is not the same thing.
An open differential will direct power to the wheel with the least amount of traction, while a limited slip differential directs power to the wheel with the most amount of traction. The locker, of course locks both wheels together.


It sounds like the E-locker would be the best way to go for ice and snow. Turn it on when you lose traction, turn it off when you have traction. The reality is quite different. First - the E-locker, when not engaged, is an open differential. The open diff is the most likely configuration to get stuck in low traction situations, this forces you to engage the E-locker to get "unstuck". I had an E-locker on an F250 and really didn't care for it in the snow. The problem is, when the rear wheels are locked together they turn at exactly the same speed. Snow/ice does not provide uniform traction (or lack thereof) so the tire tread is slipping at different speeds on each side, this causes the truck to lurch excessively. No big deal when off-roading, but potentially hazardous when used at a traffic light with other vehicles on each side of you.
The FX4 package is going to add weight to your truck with skid plates. You'll also get the OEM "off road" shock absorbers. The added weight of this option is going to decrease your cargo carrying capacity for little (if any) real world benefit.
Drive ratio - what are you going to pull? The 3.73 is going to give you significantly better fuel mileage than the 4.30, but the 4.30 is going to pull a camper much better. It's a trade off. If you are going to be pulling anything 5000 pounds or more very often, I recommend the 4.30 gears. If you are only going to pull once a year, consider staying with the 3.73. The 4.10 gear is a good compromise between the two.
Hope this helps!

 

Seems as good a time as any for my first post ;-). This is still be best video explanation of a limited slip diff that I have ever found. FORWARD TO ABOUT 3:15 to avoid the fluff.


Enjoy! (yes, another forum I have to learn how to post a youtube haha)

Tracy Ramsey
Team Blenderblaster
(Soon) 2018 F250

 

I like my e-locker but another disadvantage is the lack of lateral stability when both rear wheels are spinning. That rear end can come around in a hurry when making a turn.

 

Also, the locking differential only is engaged up to 20 mph I believe. Above that it disengages.
Well worth the money in my opinion. I have been in situations where I did not need to engage 4x4 and only the locking differential because I was on some snow and ice with one rear tire and the other one was on dry ground. By locking in the rear differential I was easily able to move through it instead of sitting there spinning the one rear wheel that was on ice/snow and then having to engage into 4x4 high.

 

Nice video, haven't seen it before.

 

The Electronic differential is the greatest thing going. Works great when on snow at slow speeds (below 20) automatically disengages and reengages with speed. Saves use of 4-Hi many times. Will get you going much easier. Best thing I've ever had on a truck.

 

You must be looking at buying the 6.2 gas if you are wondering about those axel ratios? The 4.30 with the E-locker in my opinion is the only way to go. Ive had both and love the 4.30, the 3.73 always felt sluggish. I actually get better mileage with my new truck with the 4.30’s too. Not by much but it definitely is NOT worse like everyone believes it to be. My 2011 with the 3.73’s always seemed like it was geared too high and was lugging the engine and always wanted to downshift the transmission at the slightest hill or light load. Not so with the 4.30, the engine may run a little higher rpm but the engine isn’t getting lugged down at the slightest grade change. Don’t let my mileage numbers scare you because my truck runs all day while at work, I already have 988 idle hours. My overall mileage average on my 2011 was 9.1 mpg in 196,000 miles and my 2017 is at 9.4 in just over 31,000 miles. That is pulling skid steer trailers, mini excavator, etc. plus I have 2000 pounds of fuel and tools in the bed of the truck at all times. Empty I’ve seen as high as 15 mpg at 55-60 but would probably say an average of 12-13 with a mix of driving.
As for the E-locker I would rather have that because on my past limited slip axels I never had the option to lock it in permanently if needed. The limited slip never seemed to be any different than an open diff. The E-locker does unlock at speeds above 20 mph so you don’t have to worry if you forget to unlock it and head off down the road it will not self destruct, besides when it is locked in there is another yellow symbol that comes on in the cluster to remind you.

 

The difference between an E-Locker and an LSD:

An LSD (Limited Slip Differential) is actually quite simple. The standard open differential has a simple pinion gear between the two axles that provide the drive to either rear tire. An LSD simply adds a clutch mechanism in place of the Pinion Gear. The clutch then prevents one wheel from spinning effortlessly when traction is lost. The clutch reduces the effect of the open differential by providing drive to both. If both rear tires have adequate traction to overcome the clutch in the differential, then the clutch will slip and allow the vehicle to turn without binding or skidding one of the rear tires. In most low traction situations (wet pavement, mud, snow, etc...) the available traction will not overcome the clutch and both tires will maintain drive.

An E-Locker (which my truck has as part of the FX4 package), when the E-Locker is engaged the differential mechanically locks the two axles (and thus the rear tires) together. They cannot turn at different speeds. This works very well in low traction situations (mud, snow, ice, gravel, dirt, etc...), however, it will bind and drag one tire on dry pavement when turning.

The differences in operation are also simple: The LSD is completely passive. You don't have to do anything and it should be about as effective as a locker in most conditions, including normal driving where it would improve overall traction. The E-Locker, once applied, would have no slip. So in low traction conditions it is very effective but you have to turn it on. And, as noted in an earlier post, it typically turns itself off above a preset speed (like 20 mph) and is not effective in normal driving.

My preference would be to chose the axle ratio that I wanted and live with whatever the specific differential comes with it.