Why Order an eLocker or Limited Slip Differential?

[356]

This in an honest question and is designed to help inform those planning on ordering a new Ram. I understand in some rare situations a locker or traditional limited slip differential is helpful, but for 99% of 4x4 owners, the option will never be used and the standard Brake Limited Differential works fine.

So, when should the average buyer pay extra for an E-lock or limited slip differential?

From the owners manual: A feature of the TCS, Brake Limited Differential (BLD), functions similar to a limited slip differential and controls the wheel spin across a driven axle. If one wheel on a driven axle is spinning faster than the other, the system will apply the brake of the spinning wheel. This will allow more engine torque to be applied to the wheel that is not spinning. BLD may remain enabled even if TCS and ESC are in a reduced mode.

 

[SpeedyV]

First, a true LSD will outperform a ‘simulated LSD’ without interfering with the braking system’s normal tasks.

In a previous thread on this forum, I wrote the following (with minor edits for context):

A limited-slip differential is great at providing a degree of automatic correction for unanticipated loss of traction. They don't guarantee traction in all conditions. Auto 4WD (if equipped) also helps to compensate for loss of traction, albeit in a very different way, and via a far more complex system. Most of the RWD and 4WD vehicles I've had over the years have been equipped with some form of an LSD, and my current vehicle has both an LSD and auto 4WD (and 4WS, which can make a low traction situation much more fun).

An electronic-locking differential enables the driver to prepare the vehicle for anticipated slippage, effectively pre-locking the axle vs. waiting for the LSD to kick in. This can provide a higher degree of control to the driver, especially if in a situation where sudden vehicle movement due to loss of traction would be undesirable. Think of a boat ramp, low water crossing, etc. where you want to “go in prepared”. I've not owned a vehicle with an e-locker, but I look forward to testing it in a 'sticky situation' sometime soon.

 

[VaderRebel]

After living with the LSD on my 16, I was disappointed at times where it showed it's limitations. Thats why the elocker was a no brainer for me this time.

 

[Agitated]

Yes but the limitation of an elocker shows up in ice and snow conditions. An elocker is on or off, and has no limited slip capability (usually. The TJ Rubicons had both features but caused them to be weak and only so-so in each mode). A locker is a no-no in snow and ice so you’re left with an open differential only; where a limited slip will perform better.
So the question that needs answered is how will you mostly be using your truck and in what conditions?

 

[VaderRebel]

I beg to differ, in 4hi with LSD my 16 Rebel was less capable in snow and ice than my 02 Dakota... I'm not talking on roads, I'm talking drifts and deeper snow, unplowed snow storm covered roads. It remains to be seen how the elocker will act in conditions I expect it to help in... I may be in for a surprise.

 

[CornTrucks]

We drive our pickups in mud all summer long during irrigation season, and we have never had a locker or limited slip differential. We have never gotten a vehicle stuck, so I do not think they are necessary unless you have a very specific reason for wanting one. With the modern traction control systems, I’m not entirely sure what that reason would be.

 

[Biga]

What do you plan on doing with the truck? The Elocker is more for offroading while the limited slip is for onroad driving. The elocker is not going to help in every day driving like when making a right hand turn into busy traffic on wet pavement.. The Elocker will provide more traction in on hardcore off road situations as it splits the power evenly to the rear wheels.

 

[Wxgs333]

For normal driving conditions, to me as long as it is not a torson (mechanically instant torque transfer), the clutch driven lsd would have similar response time and effect as the braking assist traction control.

That's why I chose e-locker when ordering--- it's for low speed crowl, but covers the situation a lsd barely handle.

 

[Ramjack]

How about for a boat ramp?

 

[Cannonball]

How about for a boat ramp?

Locker boat weight on rear end = traction for daaays.

 

[SpeedyV]

Locker boat weight on rear end = traction for daaays.

(Plus 4WD, of course...)

 

[356]

How about for a boat ramp?

4WD is ideal, but with traction control BLD I never needed it on my Gen 4. However, that is the type of situation— non 4WD— that the e-locker made sense.

 

[go-ram]

Two questions for the experts out there:

1. Is the E-locker mechanism the same "locking" mechanism" as the limited-slip-differential (LSD) employs when it activates?

2. What about longevity of the two systems? I have heard that most LSDs wear out their clutch packs fairly early in a truck's life, and they "fail" (wear out over time) in a way that most owners don't detect, so many people effectively have "open differential" even though they think they are still driving a LSD vehicle (because the LSD clutches wore out without them knowing it).

Thanks!

 

[SpeedyV]

Two questions for the experts out there:

1. Is the E-locker mechanism the same "locking" mechanism" as the limited-slip-differential (LSD) employs when it activates?

2. What about longevity of the two systems? I have heard that most LSDs wear out their clutch packs fairly early in a truck's life, and they "fail" (wear out over time) in a way that most owners don't detect, so many people effectively have "open differential" even though they think they are still driving a LSD vehicle (because the LSD clutches wore out without them knowing it).

Thanks!

See http://www.eaton.com/ecm/groups/public/@pub/@eaton/@per/documents/content/ct_128302.pdf for some great info.

 

[DeanKing]

I discovered the value of LSD rears about 20 years ago when I parked one entire side of my 4WD Blazer (that didn't have LSD) in a snow bank because it was the only parking spot left. It took someone to pull me out once the 2 passenger side wheels sunk even though the two driver side wheels were on dry pavement. An elocker would accomplish the same thing in this case. But in theory I agree with @SpeedyV . An LSD should provide you better intermittently slippery road traction. It all depends on how you drive and how you know to drive. I have no doubt @CornTrucks never got stuck in mud without either one if they have a lot of experience in the mud. You would need the right combination of events to get stuck in a 4WD truck and part of that is knowing when not to slow down.

Lets look at the three systems in terms of off switches:
1) Traction Control can actually get you stuck. I have a hilly driveway and live where it snows. You need to get a running start and keep moving even if the vehicle starts slipping. It has happened in a 2008 Rav4 AWD that did not have an off switch for traction control. I now always make sure the vehicle has an easy access off switch for it (which 98% of them do). I feel this is one of the most overrated technical systems on a vehicle. Sounds good on paper but the driver should be better than a system like this.

2) Elockers have off switches because they are only appropriate for off roading. They inhibit proper turning because the wheels are forced to turn at the same rate. Great for straight line traction. Bad for high speed turning.

3) LSD. No off switch. It just does what it needs to do when it needs to do it. It is not mechanically susceptible to premature failure from use nor does it consume extra fuel. No switches. Technology that has been around for many decades.

A poster on the other thread discussing this indicated that his elocker was also an LSD based on his testing. This has not been my experience with the Jeep Rubicon elockers but the Ram engineers may have done something clever.

 

[Cannonball]

To me, the urban weekend boat towing wet tire shining tropical climate truck owner, I know I want comfortable first, capable second. I'm able to (hopefully) get a 2WD this time around because of the elocker. I know that when I need it, it will be there to slowly and precisely get me out of a bind (again, boat ramp or tailgating). No maintenance. No LSD clutch spinning wheels and hoping. And! A 2WD elocker is $3000 less than toting around a few hundred extra pounds of maintenance requiring 4x4 components.

I know some will scream resale value! But no one spends 3k more for a 5 year old truck just because it has 4WD, they are nearly identical in price you just have a more limited market depending on where you live for one OR the other.

Everyone is different though. To each their own.

 

[Cannonball]

@DeanKing. The e locker in the ram 2019 is an open diff when not locked.

http://www.eaton.com/us/en-us/catalog/differentials/eaton-elocker-differential.html

 

[Ranchram]

Thank you all so much for all the great info on this thread. Particularly the last post by cannonball makes me particularly glad I ordered the elocker.

 

[VaderRebel]

@DeanKing, I mentioned in another thread that my elocker had LSD tendencies when not locked, and I think that can happen in some cases with open diffs. BUT, there is no mistake when you turn on drive pavement with the diff locked that it is for offroad/slippery conditions only.

I'm glad I have it... even though I haven't had a chance to put it through it's paces, I do look forward to getting out there and making it worthwhile.

 

[356]

My original question and helpful responses has prompted me to do more research. Here's a link to an Interesting article from a UK 4x4 site supporting BLS On the farm, I depend on the 4x4, plus it’s nice in the snow. I used to have limited slip diffs in my 2wd trucks in the days before traction control. I was impressed at the capability of my Gen 4 with TC in 2wd and an open diff.

Here is one quote from the article: Modern BTC will almost always beat a single locker. Take a vehicle that’s crossed up on a muddy slope, diagonal wheels in the air, and it’s got a rear locker only. You move off slowly, but the car is driven really only by the rear wheels and that’s too much torque for the single rear tyre with traction which slips sideways. In contrast, BTC will very slowly feed in just as much torque as the two wheels on the ground can handle (like a twin-locked vehicle), and you’re away.

I can clearly envision situations where the e-locker would come in handy, and I like the fact it’s an on-off option, unlike LSD.