Rear Automatic Lockers

[downshift]

A center diff is for providing AWD for on road use. It's useless off road (hence the CDL for locked driveshafts). That's why it is a hold out in some of the luxo stragglers that you list. It's not offered in the aftermarket, because no one wants it off road.

I took my 4th gen (with the torsen center diff) off road many many many times. At my level of off roading, it's perfect. Only very rarely would two tires slip (one front and one rear) requiring me to lock it. 99.999% of the time it's what I need. And on snow it's clearly superior.

 

[downshift]

Sounds like you need to push the gas down harder and get some oversteer going.

Now why didn't I think of that??? Perfect solution!

 

[Gone4Wheeling]

A center diff is for providing AWD for on road use. It's useless off road (hence the CDL for locked driveshafts). That's why it is a hold out in some of the luxo stragglers that you list. It's not offered in the aftermarket, because no one wants it off road.

Sorry but I disagree.

The full time 4 wheel drive has it's place off-road which in my mind is typical Colorado type rocky roads with switch backs where many times has good traction but the sharp turn requires the front and rear drive shafts to turn at different speeds to negotiate the turn without forcing tires to break traction. This causes high stress on the driveline which is unnecessary with the center differential capability of full time 4 wheel drive transfer cases.

For applications like sand or mud situations, having the center transfer case locked doesn't matter much since sharps turns allow the tires to break traction to compensate for the front and rear axle to continue turning at the same speed which is not putting too much stress on the drive train due to the lower traction of the tires.

Yes the down side of full time transfer case is lower gas mileage, I am willing to take that for the advantage it provides in the type of terrain I like to drive in.

Hence my plan to purchase a Limited and researching which rear lockers are available in case I am not satisfied with the ATRAC performance acting as a front and rear limited slip/locker or what ever is is considered.

 

[dezertbomber]

Hence my plan to purchase a Limited and researching which rear lockers are available in case I am not satisfied with the ATRAC performance acting as a front and rear limited slip/locker or what ever is is considered.

ATRAC is legit. Only drawback is the shuttering/sometimes inconsistency in when it applies power to the grounded tire, which hasn't really ever bitten me, but I could see a potential on something sketch like on Hell's Revenge or something along those technical lines where that extra bump that happens when power is transferred messes you up and puts you over.

Overall though it works great. Recently went up a super rutted hill here in San Diego area (hanglider hill) and it crawled up with tires at street pressure so smoothly.

 

[Gone4Wheeling]

ATRAC is legit. Only drawback is the shuttering/sometimes inconsistency in when it applies power to the grounded tire, which hasn't really ever bitten me, but I could see a potential on something sketch like on Hell's Revenge or something along those technical lines where that extra bump that happens when power is transferred messes you up and puts you over.

Overall though it works great. Recently went up a super rutted hill here in San Diego area (hanglider hill) and it crawled up with tires at street pressure so smoothly.

That's good to hear how well the ATRAC works which for me would be nice not to have to upgrade the standard open rear differential of a Limited.

 

[02SE]

Try it on icy mountain roads. I've spun many times with lunchbox lockers, despite driving carefully. Most people driving 4runners aren't going to like ratcheting noises or chirping tires in every parking lot turn, let alone 720s when they hit a patch of ice going up a hill.

Open diff with ABS based traction control is far superior on road in 99.9% of circumstances. Selectable locker is better off road in 100% of circumstances.

Until recently, the 5th gen 4runner has been expensive enough that no one would sweat a few hundred dollars in price between a lunchbox and an ARB, so there hasn't been a market with the revised rear diff.

I was going to say the biggest pucker factor moment I've ever had in a vehicle, was on an icy, off-camber, shelf road, with a detroit locker...

 

[downshift]

ATRAC is legit. Only drawback is the shuttering/sometimes inconsistency in when it applies power to the grounded tire, which hasn't really ever bitten me, but I could see a potential on something sketch like on Hell's Revenge or something along those technical lines where that extra bump that happens when power is transferred messes you up and puts you over.

Overall though it works great. Recently went up a super rutted hill here in San Diego area (hanglider hill) and it crawled up with tires at street pressure so smoothly.

ATRAC, MTS and Crawl Control are indeed legit. They will certainly work for most people in most situations.

But there's always pros and cons, for both ATRAC and limited slip diffs.

A LSD actually sends power to the wheel with greater traction. With ATRAC, that power is expended in the brakes. On the flip side, a LSD won't work with one wheel in the air while ATRAC will.

Best to have both!

 

[dezertbomber]

ATRAC, MTS and Crawl Control are indeed legit. They will certainly work for most people in most situations.

But there's always pros and cons, for both ATRAC and limited slip diffs.

A LSD actually sends power to the wheel with greater traction. With ATRAC, that power is expended in the brakes. On the flip side, a LSD won't work with one wheel in the air while ATRAC will.

Best to have both!

Definitely agree on having both being better, especially considering that ATRAC only works in 4Lo, so having an LSD would help all the time instead of only in slow speed, crawling settings.

Does the 4R's factory rear locker work all the time (prob up to a certain speed) or only in specific drive modes?

 

[downshift]

Definitely agree on having both being better, especially considering that ATRAC only works in 4Lo, so having an LSD would help all the time instead of only in slow speed, crawling settings.

Does the 4R's factory rear locker work all the time (prob up to a certain speed) or only in specific drive modes?

Nope, the factory rear locker only works in 4L. There's a mod that will let you use it in 4H. I haven't done the mod so I can't speak too much about it. When you need the rear locked, you're probably going pretty slow anyways, so no real need for me to have it locked in 4H.

 

[dezertbomber]

Nope, the factory rear locker only works in 4L. There's a mod that will let you use it in 4H. I haven't done the mod so I can't speak too much about it. When you need the rear locked, you're probably going pretty slow anyways, so no real need for me to have it locked in 4H.

I live in SoCal and used to race desert trucks, and would want to have the rear locked for higher speed use to allow me to swing the rear out when desired. Many desert trucks use a spool to have a constant lock, no engaging or unlocking possible.

 

[downshift]

I live in SoCal and used to race desert trucks, and would want to have the rear locked for higher speed use to allow me to swing the rear out when desired. Many desert trucks use a spool to have a constant lock, no engaging or unlocking possible.

I can see that. For racing, you want to be able to rotate like that. Kind of like the Scandinavian flick in rally racing.

But when I'm driving up the snow and ice covered twisty mountain road to my favorite ski area, cliff on one side mountain on the other, traffic coming both ways, the last thing I want is for the rear to step out.

 

[dezertbomber]

I can see that. For racing, you want to be able to rotate like that. Kind of like the Scandinavian flick in rally racing.

But when I'm driving up the snow and ice covered twisty mountain road to my favorite ski area, cliff on one side mountain on the other, traffic coming both ways, the last thing I want is for the rear to step out.

All depends, while it's more aggressive driving, knowing how to utilize oversteer and your vehicle's power can prevent certain types of accidents, especially in low traction settings. But yes, in most conditions you won't be wanting the rear end locked and/or engaging in oversteer.

Coming from a 2WD truck background, using oversteer/drifting techniques is both super fun and sometimes a must.

 

[downshift]

All depends, while it's more aggressive driving, knowing how to utilize oversteer and your vehicle's power can prevent certain types of accidents, especially in low traction settings. But yes, in most conditions you won't be wanting the rear end locked and/or engaging in oversteer.

Coming from a 2WD truck background, using oversteer/drifting techniques is both super fun and sometimes a must.

Agree. I've done some of that in an autocross setting. No, not in my 4Runner, I have another car more suitable to autocrossing. But that car won't hold my skis or all my camping gear.