I think the time has finally come to re-gear. While 4.56 is a better fit for my 32.1-33” tire size, I will be going with 4.88 gear set because I want to be slightly over-geared, but also have the option to run a 35” tire without needing to do this work again if/when I long travel the truck.

What I am torn about is my rear locker / diff option. I was hoping to talk it out because I am kinda torn on the direction I should take this. Perhaps I can gain some insight.

I am thinking of one of two options… an actual E-Locker from Harrop or a Torsen Mechanical Limited Slip like the Detroit TrueTrac.

Truthfully I am not that into rock crawling or hard technical trails where getting a wheel off the ground is a regular occurrence. I am however into zipping around in the desert, driving in sand, and doing some light dune driving within the capability of the truck.

To a degree I feel that the LSD would be a better choice because its “always on” and always delivering power to both wheels. Probably helps a lot with traction in deep sand and in other driving scenarios. I guess I could always drive around with the e-locker engaged if I am going in deep sand as well, but my concern was to do with turning under acceleration. Being fully locked would make it easier to kick out the rear and “steer with the throttle”, but I feel that might be a bad thing with a top heavy SUV. The LSD (I think) would allow for a smoother power delivery without breaking traction.

Does anyone have any thoughts? I know what to expect with a locker, but not with an LSD. Am I making the wrong choice here?

I'll start by saying I'm more used to full size domestic trucks with solid axles.
I would think a selectable locker would be better for the 4runner, mostly due to the traction control system. A Detroit type locker allows some slip around corners and when in bad traction, they can also be kind of harsh and bang when they start slipping when turning. You still can get some front end push while steering, especially in the rain or snow. They do offer a huge traction advantage over open diffs.
A locker will allow totally normal driving until you need more traction then the traction control can offer, then lock front and rear. Use both when needed and when you need more steering unlock the front, make your turn and re lock if needed.
I have Detroit lockers in my old army truck where you can't really tell the front end is ratcheting because the ride is so horrible anyways, the 4runner will get selectable locker of some sort when the time comes.
I just think it'll work better with the vehicle overall, lock the center diff, traction control goes off then the diff lockers go on and it's game time.
Just my opinion.

I think the True-Trac is the way with these vehicles.

I was under the impression that would be more of a characteristic of something like a “lunch box” locker when it engages.

From discussion with my diff shop, one of the advantage of a helical gear mechanical LSD was a very smooth transition / feel even during steering.

I forgot to mention that I will most likely be leaving the front diff open. The plan is only to put something in the rear.

I vote True Trac. Then again I am a bit biased.

Search my threads on my thoughts and feedback.

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@Mike07SE

If you dont mind me asking, what type of driving do you do with the truck that made you opt for a TrueTrac over other options?

Any additional info you can pass along regarding what I might expect in my use case would be appreciated.

To be honest I am a bit surprised that I am getting support for the Torsen LSD. I thought most would have been steering me towards the locker.

I went through all this debate like your doing now about a yr ago.
I do more off road/rock and snow.
I've seen too many problems with the air lockers, so was weighing more towards the true trac and glad I did. I do more street driving versus the mountains
.if you get in the loose ground, sand, gravel, snow, it pretty much becomes a possi rear end I notice. Everyone thinks I put a locker in. On the street I like the way it will switch power side to side a lot quicker than our stock setup.

It also works great if you do get into the rock spectrum, it pairs well with the Atrac system.

Reading on your post for what you want it for, I personally think this is a good choice for you. I don't regret not going with a selectable locker 1 bit at all.

I've drawn out my reasons in other posts in regards to the TT.

Quite simply, most of my driving is on roads and winter. Offroading entails wooded trails that is typical in the Appalachian areas. If I were tackling rocky terrain like Moab I probably would've done a locker. This was IMHO the best setup to have in everyday driving.

I bought the Torsen for mine, similar reasons.

I only know traction control systems and the 4R e-locker. I did look at True Trac etc when I was considering a dedicated trail Jeep.

I will say this: Unlike my previous Subaru, when the 4R loses traction it does not merely stop and spin, it can move sideways violently which is scary. I knew that on paper from Jeeps but experiencing it in 4H with no aids, 4L with no aids, and 4L with a-trac has made me use either MTS or the locker preventively, depending on the challenge. In fact when I am in 4H I now always use the sand mode. No more surprises. So if you cannot use A-trac in 4H, the True Trac will be great in the desert.

However, in the rocks I love the locker. I absolutely wanted a real locker and I really like it in rocks and challenging loose dirt/smaller rock/steep climbs situations.

So I would say that for desert runs the True Trac sounds better to me, assuming Atrac is 4L only. However, if your model can use A trac in 4H, then a full locker sounds better to me. You may want to do some rocks, you never know.

In sum, I now use 4H with MTS in sand mode all the time or 4L with MTS on one or another mode. Locker: as needed. Thanks to the 6112/Icon 2.0, I no longer need 4x4 to feel in control on dirt roads.

I don't have electric traction aides but I do have the TT. It's marvelous. I've gone through some pretty aggressive basketball sized rock gardens, uphill and it never skipped a beat. I love it so much I was gonna put one in the front also but I read about too much fitment issues. That, and I like the idea of having somewhere for the power to go if you get hung up and re-grab if that makes sense. Fully locked=more broken.

I also want to say that not being fully locked sort of forces you to take better lines and be more aware. If even on a subconscious level. Like "well I know I'm locked so F it I'll just jam straight through" vs "ummm I better play it safe and just make sure I take the route that's a for sure good ideal"

I also can't say enough good things about Zuk in AZ. Gearinstalls.com . If you can afford the down time, ship it out and have him rebuild your 3rd member. He's the absolute best for that.

Short answer: I think you'll love the TrueTrac for your described usage. It's effortless, switchless, airless, and effective.

I've read a couple threads you've posted in about your LSD -- clearly you've done your research.

Hypothetical question -- could you install both a LSD AND a selectable locker? Similar to how the center diff is set up on the 4th gens? Perhaps it would be overkill and prohibitively expensive, but it's not clear to me whether or not this is even an option.

I've had a lot of vehicles with LSD's in the rear. Personally, I don't like them at all, especially in winter for on-road driving. When those rear tires break traction on ice, it gets hairy quick.

Personally, any locking mechanism I install in a axle would/will be an e-locker. There is nothing better than an open diff for on-road use, in pretty much every circumstance. When you hit the dirt, just lock it up, and it's always ready to go.

There is always the possibility if someone makes one. But no, you have to choose one or the other. It's been a really long time, but I do recall when I had a Jeep there was a manufacture that made an LSD that could be electronically locked. Not sure if they're still around.