Locking front diff vs Limited Slip

[Option01]

Harrop (Eaton) E-lockers have a problem with unlocking when you change drive direction.
Harrop Eaton E-locker Disengagement Examples | Watch before you buy - YouTube

My understanding is that video was reviewing the older 2-pinion design and that the newer 4-pinion model is a big improvement. I believe the issue of some "slack" before re-engaging when changing direction still exists but is greatly reduced in the newer version. **EDIT** I learned from talking with Eaton that there are really two new Elocker designs. The standard Elocker4 has replaced the older 2 pinion model and is stronger but exhibits the same issue of "slack" when changing directions. There is also the newest "Elocker4 Directing Acting" model that has a different engagement mechanism so it does not have the issues with "slack" and is theoretically stronger but it is only compatible with Dana 60/70 axles.

To the OP - I'm planning to get both front and rear e-lockers from Eaton installed next month. After a lot of research, I believe they will be the best fit for what I want. However, I intend to use them primarily for overlanding in the snow/mud so your needs may be different.

 

[JZiggy]

Figured I'd post a link to my front TT install tech since we seem to be going on a technical deep-dive

 

[Bad Luck]

My understanding is that video was reviewing the older 2-piston design and that the newer 4-piston model is a big improvement. I believe the issue of some "slack" before re-engaging when changing direction still exists but is greatly reduced in the newer version.

To the OP - I'm planning to get both front and rear e-lockers from Eaton installed next month. After a lot of research, I believe they will be the best fit for what I want. However, I intend to use them primarily for overlanding in the snow/mud so your needs may be different.

The redesign happened in 2018 and they went from a 2 pinion to 4 pinion design which did help, but the problem still exists. The video I posted was the 4 pinion design and had been replaced by Harrop twice and it was still unlocking on it's own.

 

[Option01]

The redesign happened in 2018 and they went from a 2 pinion to 4 pinion design which did help, but the problem still exists. The video I posted was the 4 pinion design and had been replaced by Harrop twice and it was still unlocking on it's own.

Are you sure that the video covers the 4 pinion design? AllOffroad Adventures TV posted these replies below the video which gave me the impression they were working with the original 2 pinion model:

"In general, I have no issue with E-lockers and would like to test the Eaton E-locker 4 which Eaton created to exactly get around the limitations of the Harrop/Eaton e-locker. Unfortunately only available for dana 60/70 at this stage."

"I hope one day Harrop brings the direct-acting e-locker design for the Dana 60/70 down for other diffs as this would be an e-locker I install until then I pass based on my research and experience. Why do you think Eaton released a direct-acting e-locker in the US? "

**EDIT** I still don't know if they had 2 pinion elockers or the newer design with 4 pinions but it appears he is talking about Eaton's newest model, the "Elocker4 Direct Acting" which is a totally different design and theoretically should resolve the issues they've experienced. However, it is currently only available for Dana 60/70 axles.

 

[Bad Luck]

Are you sure that the video covers the 4 pinion design? AllOffroad Adventures TV posted these replies below the video which gave me the impression they were working with the original 2 pinion model:

I stand corrected, but doesn't that also mean you will be getting the 2 pinion design that they showed unlocking in the video?

 

[Option01]

I stand corrected, but doesn't that also mean you will be getting the 2 pinion design that they showed unlocking in the video?

My understanding is that Eaton replaced the old design quite some time ago and now only sells the newer 4 pinion design (at least here in the US). If you Google the part numbers for the Eaton Elockers that fit our 3rd gen 4Runners (14218-1 and 14211-1), the retailer websites all show "Elocker4" in the title.

Those posts from AllOffroad Adventures TV are almost a year old so I'm guessing that Harrop might not have licensed Eaton's newer design right away so maybe they were not available in Australia yet (or maybe still are not).

**EDIT** While Eaton has upgraded the elocker for our 4Runners to an Elocker4 (4 pinion design which is stronger than other older 2 pinion model), that is not the fancy new/improved design that AllOffroad Adventures is interested in trying out. That would be the "Elocker4 Direct Acting" model which has a totally different mechanism but is currently only available for Dana 60/70 axles

 

[gamefreakgc]

I didn't realize exactly what a lunchbox locker was, but further searching revealed enough for me to realize I don't want one. When I was looking for my third gen I drove one which likely had a lunchbox on it, it would bind around corners and it sounded terrible.

Limited slip or airlocker is what I meant to say.

Do limited slip differentials in the front have the same downsides as they do in the rear?

If I did fit an air locker in the front it wouldn't make much sense not to fit one in the rear as well since a majority of the hardware would already be in place. If you consider that the total is 5k (RD90 front RD132 rear, plus all the kit needed), I wouldn't do this all at once but that is till a large price.

If I eventually put an air locker in the back would it at least save me the trouble of changing the rear gear ratio like I would if I went with the stock E-locker?

Does anyone besides ARB make air lockers for our 4runners?

Also I think the truetrac LSD for our 4runners was discontinued

I don't wheel very much, and only crawled in my 4Runner once. Not really my thing so take that into consideration. Mostly just dirt roads and stuff here but I love my LSD it's very helpful on-road with traction for my specific build and I never have to think about it, it's 'always on'. The one time I did go wheeling, I had less issues with loose soil and rocks with highway-rated tires and an LSD than the other guys with A/T tires with an open diff. It's a solid improvement. I hardly ever use 4WD anymore for that reason, 2WD with an LSD is more than enough.

The exception to that is snow. Doesn't help there.

 

[Pyral]

Is fitting an E-locker as simple as installing it in the diff, running the wires to the battery and a relay that is controlled by a switch in the cabin?

Also how is the relay controlled once in the diff, do I have to drill a hole in my diff to fit a wire?

Would the truetrack LSD need to be changed if I ever fitted an Elocker in the rear diff since the gear ratio at the back goes from 4:10 to 4.30?

 

[Bad Luck]

Is fitting an E-locker as simple as installing it in the diff, running the wires to the battery and a relay that is controlled by a switch in the cabin?

Also how is the relay controlled once in the diff, do I have to drill a hole in my diff to fit a wire?

Would the truetrack LSD need to be changed if I ever fitted an Elocker in the rear diff since the gear ratio at the back goes from 4:10 to 4.30?

The Toyota rear e-locker has a different mounting flange pattern than non e-locker rear differentials so you will either need to find a rear e locker axle housing (or complete axle assembly) or modify your non e-locker housing. It requires grinding part of the opening to clear the differential components and drilling/tapping a few more stud holes.

For the wiring you will need the factory module/switch/wiring or make your own. I would recommend using an aftermarket wiring harness/switch/components if you don't have the factory components: E-LOCKER FULL KIT SWITCH & CABLE - 12 Volt Guy

A toyota rear e-locker can only be an e-locker. You cannot install an lsd or any other traction assist device into that differential.

 

[JohnMc]

Yeah, e-locker wiring is NOT a simple on-off switch. It's not quite rocket science, but it's a bit more complex. Need the 12V+ to go one way to lock, and then the other to unlock. And keep track of the limit switch so you know what's going on in there as well.

I will readily admit that I haven't wheeled with an LSD up front, but based on PURE IDLE SPECULATION (enough of a disclaimer?) I don't think it would be that ideal. LSD's only transmit significant traction to the loaded wheel when there's a bit of spin in the system. And with a locker in the rear and in 4WD, the only way you're going to get significant spin is if all 3 other tires are spinning, and only then will it transfer some torque to the front wheel with more grip than the unweighted one.

And spinning wheels are sliding wheels (unless it's very flat and level side to side).

Not to say it wouldn't help in a situation like that, it would. Just that a front locker would work better - get that last front wheel to contribute while the other tires are still going, not already spinning.

I still have an open diff on the front of mine (e locker in the rear). My wife has an Arb up front and an e-locker on the rear of hers. That front locker def does make a difference in extreme situations.

 

[G_Raw]

I love my air lockers front and rear. I can't comment on TT or LSD's with a 4runner and how they compare to the airlockers. What I can say is that when maneuvering my front over tougher obstacles it is nice to have a selectable locker that I can turn on and off just to get through the event and not something that try to engage when I'm past the point of needing it. I wonder if a TT would still engage with enough torque transfer while clearing an obstacle that results in loss of wheel contact on one side and transfer torque to the contact side that would risk breaking the CV all during a point where that sort of traction control is no longer truly needed on the obstacle.

I say this because I have learned that while clearing a front obstacle while using my locker that it is crucial to maintain the foresight to turn it off once you don't need it's help anymore...even if you are still midway through the obstacle. This is because the torque transfer that occurs is rough on our front IFS Diffs and CV's. I have broken a couple front CV's due to not disengaging the locker in time.

 

[Pyral]

This is because the torque transfer that occurs is rough on our front IFS Diffs and CV's. I have broken a couple front CV's due to not disengaging the locker in time.

I've read about this. Did you fit beefier CV axles to cope with the additional stress?

A lot of concerns over fitting front lockers is that the IFS cant handle the stress and has a tendency to get all snappy on the trails. I also read an ancient Motor Trend article that said its a good idea to upgrade the tie rod ends too. One thing to consider is that the larger your tires are, the more stress you'll be applying to your ifs.

 

[phattyduck]

I will readily admit that I haven't wheeled with an LSD up front, but based on PURE IDLE SPECULATION (enough of a disclaimer?) I don't think it would be that ideal. LSD's only transmit significant traction to the loaded wheel when there's a bit of spin in the system. And with a locker in the rear and in 4WD, the only way you're going to get significant spin is if all 3 other tires are spinning, and only then will it transfer some torque to the front wheel with more grip than the unweighted one.

LSD options get even more complicated when you consider a Torque-sensing type (Torsen, or Trutrac) vs. clutch-type vs. viscous. Each type acts differently. Not that there many options for the 7.5" front, just a general comment that comes up more often in performance cars instead of off road trucks.

Your point about slipping sideways when both wheels spin is also important - it matters for both on-road low traction situations and off road off-camber situations.

My Alltrac Camry is a drift machine in the snow because it has a Torsen (like Trutrac) rear that basically stays locked in low traction situations. It was that way even when it only had 100hp - and now it has ~275hp. Fun, but you HAVE to know what you are doing and be ready for it.

-Charlie

 

[G_Raw]

I've read about this. Did you fit beefier CV axles to cope with the additional stress?

A lot of concerns over fitting front lockers is that the IFS cant handle the stress and has a tendency to get all snappy on the trails. I also read an ancient Motor Trend article that said its a good idea to upgrade the tie rod ends too. One thing to consider is that the larger your tires are, the more stress you'll be applying to your ifs.

I run FJ tie rods. I'm still running Napa aftermarkets lifetime warranty CV's and just wrecking my way through them no paying s dime after the first 3...a set and a trail spare... all has been good that route.Working my way to 35's and may consider some beefier CV's then however my manual hubs are an issue for all companies other than Lotus... and at $2400 for a set and spare of Lotus I'll probably go down the rabbit hole of SAS.

 

[psea17]

Thanks for the info. I was thinking if I went with a front locker I'd go with a Harrop but now you got me thinking.

Timmy, was wondering if you had made a decision here or if your research had steered you in a particular direction. I'm considering a front locker now that i just secured a 4.3 rear axle w/ elocker along w/ the matching front diff.

psea

 

[96RedRunner]

I've been running Harrop front 2 yrs. 10k mi how it operates has not been an issue yet.
On a 01 did E-locker rear swap wanted E-locker front, if it breaks, I'll deal with it just like ARB.