Atrac aint up to the task.. Locker choices?

[RonJR]

I'm not seeing the TrueTrac listed for 4th gen 4 Runners. Do you have a part# that fits? What mods have to be done to make it fit?

I'm not absolutely sure, but from what I've read the 4th gen 4runner uses the same 8" 4-pinion 30-spline rear diff as has been used since the V6 in the 2nd gens, in which case the Truetrac for a 1995 6-cylinder (P/N 913A610) would be the right one. No mods should be necessary. Just have to get the backlash between the ring and pinion right when you put it back together.

I wouldn't rush out and spend $400 on my say-so, however.

When I decide to retire my '94, I may pull the Truetrac out of it and see if it fits in the '06. But that'll be a year or two, so don't hold your breath.

 

[SSt4r]

RichN (& RonJr),
http://www.toyota-4runner.org/4th-gen-t4rs/159351-2005-v6-rear-locker.html
According to this it seems it's the right part number. In fact, it's the part I purchased and should be installed next week. I'll keep you updated.

 

[RichN]

RichN (& RonJr),
http://www.toyota-4runner.org/4th-gen-t4rs/159351-2005-v6-rear-locker.html
According to this it seems it's the right part number. In fact, it's the part I purchased and should be installed next week. I'll keep you updated.

Does anyone know what changed from 2005 to 2007?

 

[fromLRtoT4R]

Hahaha. :violin::violin::violin:

You can't come onto a 4Runner forum and tell us you got an LR4 with 2 wheels in the air and not get this.

:worthless:worthless


Pictures or it never happened.

Hey.. Sorry no pictures.. I usually don't take pictures of the outside of my car while I am driving.. Here is a short video my buddy took.. Its nothing crazy, I think for a brief second it puts 2 wheels up, but you can believe when I say that it can do it not just on rocks, it can do it in slippery surfaces going up hill. I have no bias towards any manufacturers. I just call it like I see it

https://www.youtube.com/watch?v=1T8JgERix_8

I have done things with that LR4 that no normal person should, and I decided to get a 90s Land Cruiser but couldn't find one, I ended up with an LR3 to beat around so I don't have to punish the LR4 which is really my wifes car.. I sold my LR3 and now I am trying out a 4Runner

 

[fromLRtoT4R]

What tires are you running. Stock tires are pretty awful.

ATRAC runs best at 2000 RPM with a little momentum. If you start off, and you're confident you can clear everything and just get a good start, keep it at 2000 RPM it's quite impressive, it just doesn't stop. But it needs to be smooth if you just jab the gas on and off it's not effective, it has to be steady gas, steady RPM. If you stop and try to start again often you are done for. If you climb up onto a ledge and stop to assess your positon there and try to start again, often you are done for. If you take a Toyota into the bush you will be able to come back out. You can take a Landrover into the bush, but will you come out...LOL.

ARB is what to get. I've got ARB in my 1st Gen and dual ARB in my 4th gen. Doing it again I might have gotten auto lockers in the 1st gen. But it's a trail only , mostly trailered machine. On the 4th gen, especially your 2007, it's too nice and new to lose drive-ability. Also the ARB solidifies the carrier.

An elocker, is not worth the price, it costs the same as an ARB. You will need to get a housing that has a notch for the elocker motor or cut yours, it is more finicky than an ARB, and it doesn't solidify your carrier.

It could become cost effective if you are able to get the entire rear end off an FJ Cruiser for dirt cheap.

If you can offroad and abuse an LR4 don't balk at a 1000$ ARB locker

I do realize that Atrac likes momentum, but that doesn't speak much about its abilities..
With that being said, no I don't want to pay $1000 plus compressor for the Aussie so much, which is why I stated this thread.. The though of LSD scares me a little because I think I may burn through that pretty quickly.. But if its the right choice for me, that that is what it will be..

Not wanting to hike back from the bush is precisely why I no longer have the LR3 all though to its credit, it had almost 140k miles on it and was it really good shape when I sold it.. Its just those airbags and all that dependence on electronics they have is scary. So I always knew I would land on a Toyota for serious trail driving

The reason why I do stupid shit with an LR4, LR3, and just about anything I can get my hands is because I love cars and love to test them, not because I am rich.. I am in the auto business and like to try different things for my self..

BTW, my 4Runner has 33s on it now.. They are the Discount Tire brand All Terrains.. The LR4 has the stock size bridgestone duelers, and my LR3 had 32" Terragraplers

 

[fromLRtoT4R]

I too find that the A-Trac is happier while the vehicle is in motion not stopped. I try to keep some momentum whenever possible and I feel it works better. Although when rock crawling you cant always keep the vehicle moving with momentum which makes it a little harder. Also if you drive with two feet when rock crawling this helps a little too.

Precisely what I found.. And for those reasons I don't really like Atrac.. I hoped it would get me by, but it will not... I can get a nissan murano up a hill with momentum.. lol!

 

[Mike07SE]

I honestly think that the True Trac is what you are looking for. 100% seamless, it's a Torsen setup (like the center diff and used on other cars like Audi, Subaru, etc.) so it won't wear out, and it seems to be a popular mod among other maker's platforms (LR's included). I find it to be a great marriage with A-Trac as it calms it down compared to an open setup as well as A-Trac aiding it ability to lock it up (yes I know, not 100%) and put the power down where it's needed. Also, unlike the air lockers, it's also 100% streetable which is another plus in my book. Also by doing this as well as adding a solid pinion spacer in my install I have also beefed up my rear end's strength as well.

Search and check out Shabaka's feedback on the TT as well as other threads related to this discussion. I'm sure you'll see this may be a good alternative.

Edit: I also found this article as I think it will help you relate a little more as it deals with LR's.
https://www.expeditionexchange.com/tractech/

 

[CAN-03runner]

Precisely what I found.. And for those reasons I don't really like Atrac.. I hoped it would get me by, but it will not... I can get a nissan murano up a hill with momentum.. lol!

By momentum I'm seeing it more as steady throttle. As keep the momentum, not get a running start. That's why I like the full locks, you don't need to slip for an ABS or limited slip system to kick in. And I'm always the first to get out the winch rather than try to jump obstacles.

If you can find a junk yard automatic FJ Cruiser, or maybe someone with an FJ who is doing a SAC and also changing their rear end it should plug right in and replace yours and you'd get an elocker. It might be cheaper than an ARB and compressor if you'd do the swap yourself. You'd then also be able to sell your parts to offset the cost. In fact I just did that with a few buddies of mine. Someone we know is doing a SAS on his FJC. So 4 of us together bought his entire rear end for spare parts, I ended up with the axles, someone else the 3rd, another person the elocker. And he ended up with some money to continue his project.

Keep in mind that you don't 100% need to use an ARB compressor you can use another brand. And you need a compressor to air up anyway.

Also even if a limited slip is 600$ and ARB is 1000$ you still need to setup the gears, so unless you have that ability the cost differential is just not enough for me. You still need to go through all the work of removing the axles to pull the 3rd and setup the gears. Neither is a simple swap. And if you get disappointed with a LSD you will have wasted money and might spend double to finally get a locker and do it all over again.

The other alternative I often give to people is to get a winch mount and winch.

https://youtu.be/YNFacsKnswM

 

[RonJR]

There's no doubt the ARB is a more complete solution. I'm intrigued by how the Truetrac might work with the ATRAC, though. On my '94, the TrueTrac isn't that much help when a wheel is lifted unless you're good with the brakes, but the ATRAC on a 4th gen should be much more effective than manual braking.

Installing a Truetrac and setting up the gears is not outside of the ability of a DIY mechanic. You need a dial indicator which you can get for $30 from Harbor Freight, and do some reading on the internet. Toyota Gear Installs is a good place to go for great writeups and pictures of what to do. The only thing that you need to adjust when you put it back together is the backlash between the ring and pinion - the pinion depth (which is the hardest and fussiest to set up) doesn't get touched when installing a Truetrac or an ARB, so nothing to do there. Setting the backlash on a Toyota diff is easy - just a matter of rotating the adjusting wheels until it's right, then locking them down. The nice thing is all of the delicate work can be done on the bench once you have the 3rd member out.

I can pull the 3rd from my '94 in under 45 minutes by myself, and install it in the same time. Total time to install a Truetrac would be about 3-4 hours assuming the carrier bearings are already pressed on. It would take longer if you've never done it, though.

Truetrac is available for about $450 for the Toyota rear diff, so about 1/2 the price of an ARB.

 

[fromLRtoT4R]

Yes I see that truetrac is half the cost and I am also intrigued by the thought of how it will perform with atrac. I watched a few videos and this one in particular
https://www.youtube.com/watch?v=lHIaJIhtxrQ leaves me a bit nervous. The way that jeep was fighting for traction makes it seem that truetrac may just give you enough traction to go sideways and hit a tree or a large rock.. I wish I can find a video of how it performs with atrac on some serious stuff but haven't seen anything yet. So at this point I am leaning toward some kind of manually lockable diff.

 

[duffdog]

I guess I'm doing it all wrong then.

I have a 4th gen v8 with an elocker rear. The Elocker works great because the atrac only plays with the front tires and helps tremendously in snow and on trails with 4 foot rocks and snow. I know that ARB has this ad campaign about "being able to lock your diff at any speed". But then you need air, air lines, a compressor that runs ALL the time and you better hope that you don't have to cross a river with your ARB compressor running or it will suck in a bunch of water and you are done.

BTW-- I am not really an ARB fan. I have their skidplates on my 4th gen...they are the weakest, cheapest junk I have ever seen. I don't trust that their "air locker" is of any higher quality, especially when compared to a factory Aisin Elocker.

 

[Mike07SE]

By momentum I'm seeing it more as steady throttle. As keep the momentum, not get a running start. That's why I like the full locks, you don't need to slip for an ABS or limited slip system to kick in. And I'm always the first to get out the winch rather than try to jump obstacles.

If you can find a junk yard automatic FJ Cruiser, or maybe someone with an FJ who is doing a SAC and also changing their rear end it should plug right in and replace yours and you'd get an elocker. It might be cheaper than an ARB and compressor if you'd do the swap yourself. You'd then also be able to sell your parts to offset the cost. In fact I just did that with a few buddies of mine. Someone we know is doing a SAS on his FJC. So 4 of us together bought his entire rear end for spare parts, I ended up with the axles, someone else the 3rd, another person the elocker. And he ended up with some money to continue his project.

Keep in mind that you don't 100% need to use an ARB compressor you can use another brand. And you need a compressor to air up anyway.

Also even if a limited slip is 600$ and ARB is 1000$ you still need to setup the gears, so unless you have that ability the cost differential is just not enough for me. You still need to go through all the work of removing the axles to pull the 3rd and setup the gears. Neither is a simple swap. And if you get disappointed with a LSD you will have wasted money and might spend double to finally get a locker and do it all over again.

The other alternative I often give to people is to get a winch mount and winch.

https://youtu.be/YNFacsKnswM

No offense, but I can't stand it when this video is used to talk about the effectiveness (or lack of) of LSD's. This is improperly titled as the 'LSD' portion of this is basically the ATRAC at work and the guy even clearly says that when the truck makes it up the embankment. A true LSD would have done better. An LSD with ATRAC would have done nearly as good as the white truck.

 

[fromLRtoT4R]

I guess I'm doing it all wrong then.

I have a 4th gen v8 with an elocker rear. The Elocker works great because the atrac only plays with the front tires and helps tremendously in snow and on trails with 4 foot rocks and snow. I know that ARB has this ad campaign about "being able to lock your diff at any speed". But then you need air, air lines, a compressor that runs ALL the time and you better hope that you don't have to cross a river with your ARB compressor running or it will suck in a bunch of water and you are done.

BTW-- I am not really an ARB fan. I have their skidplates on my 4th gen...they are the weakest, cheapest junk I have ever seen. I don't trust that their "air locker" is of any higher quality, especially when compared to a factory Aisin Elocker.

Who said you are doing anything wrong?

 

[brett_murphy]

I'd like to chime in with a view from left field. Don't let me current location throw you, I spent 10 years driving in upstate NY.

For driving on pavement in bad weather (snow and ice), tire choice is going to make more difference than anything. A beater RWD truck with proper snow tires will get around just fine if driven with care. People drove for years and years without AWD, traction control and all of our other modern aids. Adding AWD or an LSD is just going to improve how well the tires grip.

Now, wheeling or rock crawling is a completely different animal than driving on smooth ground. I don't have much experience with it at all, but if you lift a wheel with a Torsen (helical gear) type unit, you've got an open differential, so unless you've got something like ATRACs, using a Torsen type where you might lift a wheel without some kind of brake force distribution system seems like a waste of money.

 

[CAN-03runner]

No offense, but I can't stand it when this video is used to talk about the effectiveness (or lack of) of LSD's. This is improperly titled as the 'LSD' portion of this is basically the ATRAC at work and the guy even clearly says that when the truck makes it up the embankment. A true LSD would have done better. An LSD with ATRAC would have done nearly as good as the white truck.

You're right. Not offended here. They are refering to atrac as being a limited slip. But it has toyota vehicles so it fits. I don't like non 100% truthful videos either. A true LSD could have done better, maybe, but you think as good as the locker. And it's not really talking to the effectiveness or lack of an LSD, but more to the effectiveness of an ARB Locker...marketing material probably 100%. You have a front ARB, do you ever use it?

I don't like to blast through obstacles or mud. I acknowledge the short commings of Atrac. But I got a winch for the 4th gen before I got lockers. I want to crawl through either locked up or behind a winch rope. The best I can get my 4th gen to be little bit like my crawler is with dual lockers. Northeast trails are rocky, muddy, tight and mostly wild ungroomed trails.

An ARB or elocker is at least selectable for a daily driver. You end up having to kick up less dirt and ruin the trails less. It's a big concern for us in the north east with all the trail closures.

So in reality, if I had one upgrade to take, I'd take a winch mount and winch before getting lockers. Even with both my 4runners, dual locked, in mud you only get so far before you get stuck. In fact some sections of trails I do often, I know 100% that I'm getting stuck. So rather than try to blast through, I drop in, nice and easy go as far as I can, and then roll out the winch. Get to the other side, turn my truck around and guide the rest of the guys to do the same, once they are stuck if they don't have their own winch I hook them up and pull them across. No breakage, everyone gets back home, and lunch isn't spent in a mud pit with a side of diff oil and cv grease.

If we can agree to disagree. It doesn't really matter what you have. 4Runner, Landrover, Jeep, Ford, stock or modified. They all make up part of my offroad buddies from hard core modified to bone stock, eventhough officially we're a toyota club. Getting stuck is part of the game, I've been there, almost every trail. Lockers or LSD isn't what gets you out, winches, straps and good buddies get you out. Another aspect is not to go out alone.

This video below I've seen before and just stumbled on it again as a youtube suggestion...

https://youtu.be/-lydlwgiW6Y

I've lived something similar as the below with a buddies' F350, 35" MT tires and LSD. During some long distance expedition style driving, so not rock crawling, on wet gravel roads up north, he slipped off the gravel road and couldn't get back up and needed to be pulled out.

https://youtu.be/DjCDuXIQQYc

 

[CAN-03runner]

I guess I'm doing it all wrong then.

I have a 4th gen v8 with an elocker rear. The Elocker works great because the atrac only plays with the front tires and helps tremendously in snow and on trails with 4 foot rocks and snow. I know that ARB has this ad campaign about "being able to lock your diff at any speed". But then you need air, air lines, a compressor that runs ALL the time and you better hope that you don't have to cross a river with your ARB compressor running or it will suck in a bunch of water and you are done.

BTW-- I am not really an ARB fan. I have their skidplates on my 4th gen...they are the weakest, cheapest junk I have ever seen. I don't trust that their "air locker" is of any higher quality, especially when compared to a factory Aisin Elocker.

Yes I agree the ARB skid plates are total junk. But you need to contextulaize what they are probably meant for. They might be ok for expedition style driving, better or just as good as the stock skids But not rock crawling.

ARB for me is bumpers and Air Locker. I do think they are a quality product. How much of the price is paying for marketing and that the competiton for selectiable lockers is so little?? Mine have been problem free. And some club memeber have had them in old landcruisers for at least the 10 years I've known them....and their cruisers are like from the 1986 or so.

This weekend we removed a failed elocker on an FJ Cruiser and replaced with a known good used one. I'm having trouble with the add picture function at the moment, I'll try again later. It is aluminium. And it corrodes something fierce, so bad that it became brittle enough to break appart in your hand. The internals were still dry and like new looking, grease was still yellowish, but the rod wouldn't move in and out anymore. It's not serviceable. It's like a press fitting sealing it so you can't unscrew it for example to clean it out. So much for Aisin quality. And a large number of elockers in our FJC group end up having elockers that seize up even with breather mods. They can be saved if they haven't cracked or don't break appart when working on them. Besides mud, water and road salt, the aluminium to steel contact causes a corrosive reaction. None to my knowledge is made for a front IFS, and a 4runner without an elocker will need a new housing to receive it or have it modified with an elocker notch.

 

[fromLRtoT4R]

well people, after several more obstacle tests I have determined that Atrac just plain sucks! I am saddened to say that a 2010 Explorer, and all honda/acura awd systems I have tested performed better when 2 or more wheels start to loose traction. I now have zero confidence in atrac and am too worried to try a true track so the aussie it is! Just ordered it though amazon and everything cost me about 1000.. I have not had the time to take someone with me who could record some the testing I did but I will just leave you with this picture and let you know that it took 4 attempts to make it up this small hill and it finally made it after I began the hill at no less than 10mph and just stayed on the gas and Atrac barely was able to keep it moving.. Just to compare, neither my 2005 LR3 or 2010 LR4 ever broke a sweat getting up this thing.. I was alerted to the weakness of Atrac many months ago when I was guiding by friend who just bought a brand new taco TRD offroad (2014 model year) and damn near had to activate his locker to make it up this tiny hill.. I just though it was just him at first.. sadly it wasnt

 

[JB.]

Yeah, cross-axled and stopped is the worst case scenario for the way the 4th gen atrac works, but I gotta ask just to make sure -- are you giving it some gas and just holding steady while letting the unweighted tires do their obligatory 1 or 2 spin rotations before the atrac grabs and the truck vibrates and sounds like a giant coffee percolator before crawling forward?

If so, pardon the interruption but if not, give it a try.

On a separate note, some aggressive tires at about 18psi would probably do as much or more for you there as a rear locker. Could be I'm talking out my a$$ as I've never had a rear locker, but I'm also unfamiliar with the severity of problem you seem to be describing.

 

[RonJR]

I've not had a chance yet to test ATRAC in that situation, since I just got my '06 in December. I do know, however, that cross-axled like that was a "stop dead in your tracks" situation for my '94 until I put the Aussie locker in the front. With the locker you don't even notice the obstacle - you just keep going with absolutely no drama.

My guess is OP won't be truly satisfied with anything but a locker - might as well pony up and do it.

 

[CruzadoBlanco]

as i got into bigger and bigger rocks my atrac just couldnt help enough (a lot of stop and start on obsticles and what not), so i bought a used elocker from a 96 runner on ebay for 330 bucks. had it rebuilt and installed it with a 12vguy harness. the difference is night and day vs just Atrac. honestly modifying the housing wasnt too bad. just 2days with a dremel and a good drill was all it took. and i love it. however the actuator does take some maintenance to keep it 100%, but being a EE student helps with understanding what the issues could be and how to address them, so its not a big deal to me either.