Limited Slip on 2006 LX

Three or more Questions:

Does the 2006 LX have a limited slip rear differential? If not, why not? But if it does, why? It already has traction control.

Does the 2006 LX have a limited slip center differential? If not, why not? The lesser GX470 (at least in price) has that feature as standard equipment.

Why doesn't the LX have KDSS to allow more aggressive driving?

Steve
'06LX

Hello Steve,

Welcome to the forum. The 06 LX does not come with rear LSD. Though TRD does offer one for our rigs. I would personally add a locker, instead of an LSD.

The 06 LX has open center diff. compared to the GX which has a Torsen center diff. I'm a previous GX owner and the GX does understeer less compare to the LX when pushed to the limit. The Torsen sends more power to the rear during hard acceleration/cornering and decrease it on low traction situations. I personally don't feel any difference during normal driving. Torsen is something nice to have but doesnt really make any difference until you drive your rig hard.

On the Lexus Taste of Luxury Event, I got the chance to drive both GX with KDSS and the LX. Both have pretty much the same suspension articulation. On the slalom the LX responds faster because of the variable steering ratio but the KDSS GX corner much flatter. So best of both worlds goes to the GX.

The 120 series or the GX, 4Runner, FJ, Tacoma, Prado all ride on the same platform. It's the latest truck chassis from toyota introduces in 2003, hence it has all the updates and technological advancements all incorporated in to it. Wheras the 100 series chassis introduced in 98 is purpose built for the LX470 and Land Cruiser AFAIK.

Charleston

From the Lexus site:

"The LX 470 uses a true full-time four-wheel-drive system with a center differential that splits the power 50/50 front/rear. The system is always engaged and requires no intervention from the driver. Throw in a locking center differential, a rear limited-slip differential and lots of suspension articulation and only the driver, or worn out tires, can be blamed for sticking one of these in the mud."

I read it as having a rear limited-slip differntial. Could be false information, I dunno. LSD has much smoother engagement than traction control especially at high speed. Traction control has better ability to get the LX "unstuck." A locking limited slip differential w/ ATRAC would be the best of all worlds.

http://www.lexus.com/models/lx/review.html

I don't think the 100 ever came w/ open rear diffs. It was either the standard LSD w/ no locker or optional locker w/ no LSD (still an option just about everywhere except here). The LX was never offered w/ a locker in the States, so I think it always had the LSD (but not always traction control).

Jim_Chow said:

I don't think the 100 ever came w/ open rear diffs. It was either the standard LSD w/ no locker or optional locker w/ no LSD (still an option just about everywhere except here). The LX was never offered w/ a locker in the States, so I think it always had the LSD (but not always traction control).

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Don't know about Lexus, but the 2001 rear is open not LSD.

On the '06 the center diff lock is below the manual antenna control which is below the hazard lights button.

It's possible the LSD was dropped when A-trac came along. You can check by looking at the rear end housing from the rear of the vehicle. If it has an LSD it'll have a sticker that says "LSD fluid only". The LSD was standard until A-Trac; then it is no longer really mentioned so that leads me to believe it was deleted. As effective as it sounds from the folks with A-Trac I could see the LSD being un-necessary. It works well for my '99 all that being said.

As far as KDSS goes and why it's not on the LX; well there's already a thread on that. Search it for the details but the gist of it is that the LX's design was around before that technology existed and retrofitting it is cost prohibitive versus the rewards for having it.

Follow-up

I agree with allof the above. Having traded a GX with KDSS, I certainly agree with the handling observations but feel the "ride" over all is better in the LX. The ride adjustments in the GX were almost meaningless --- it was just a matter of how bumpy you wanted it but taking corners was similar to a X5 without SS ---very good.
I too was confused by the "New Car Report" on the Lexus site. Forbes and other reviews mention rear LSl also. I'm not too surprized that Lexus has failed to correct those observations. They didn't bother to put new pictures in their brochure --- check out the grill --- 3 chrome strips instead of the 5 on the '06. I don't think anyone has reviewed an LX in the last 3 to 5 years --- just warmed over old articles. Altho the LX made the "Most Wanted List" on Edmunds.
They are apparently abandoning a magnificent classic SUV. I wonder if the stated spec's are even correct. The 0 to 60 seems a bit conservative, for instance.
The rear LS probably is gone. My wife had it on her '99 RX but it was replaced by TRAC in 2000 or 2001.


Appreciate the responses
Steve
LX470 Classic Silver
You gotta love retro when it's made this good

Here is the rundown as far as I know. You can also go to the Slee site and see when the changes occured in his tech section.

L/C
98-99 No LSD - only rear locker or open, open is very rare and I have never seen one - heard of a couple but never seen.

00 - present, A-trac took the place of the locker. Both diffs are open. To toyota atrac is their version of an electronic locker with the actuation taking place using the brakes instead of internally with the diff.

98-99 LX Rear diff Limited slip, no locker offered. New car features book says lsd was an option, but I have never seen it without one.

00-present LX same as L/C

All l/c t-case, center diff internally in t-case. acts just like an open axle diff except front to rear instead of side to side. Acts like a locking diff (not lsd) when center diff is locked. (FYI GX has the torsen in addition to all of the above in the t-case)

Note also GX suspension is conventional in front and air in rear. LX is hydraulic at all 4 corners, So the reason the suspension feels better is because it is. I have never been impressed by the rear suspension in the GX.

Hope this clears things up.

ssvalina said:

The rear LS probably is gone. My wife had it on her '99 RX but it was replaced by TRAC in 2000 or 2001.

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And TRAC is a HUGE improvement (over LSD) to the vehicle in terms of safety and off-road capability. HUGE improvement.

tabraha said:

<snip> You can check by looking at the rear end housing from the rear of the vehicle. If it has an LSD it'll have a sticker that says "LSD fluid only". <snip>

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There is a sticker on my '99 LX rearend, near the fill hole, but it is mostly obscured by paint or undercoating; not readable, apparently not cleanable either.

But the window sticker and other info I have says "limited slip".

ShottsUZJ100 said:

And TRAC is a HUGE improvement (over LSD) to the vehicle in terms of safety and off-road capability. HUGE improvement.

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Yes the vsc/trac make a huge difference, especially in slippery conditions. Schotts is right. There is also the next generation version of this sytem that is out on a few vehicles that is another huge improvement over the vsc system. It is called VDIM, it actually smoothes the transitions between the three systems(abs,vsc,trac) think square bowl compared to round bowl and rolling a marble around in it. The vsc has to react to something you've already done, the VDIM can predict what you're planning and react for you before it even happens. So the slide that is inevitable will never happen because it reacts so fast.

I've heard stories about vehicle testers who will run a snowy slalom course with the systems on and set a time then spend the rest of the day trying to beat that time with the system off. It's nearly impossible even for the best drivers.

It does take some of the seat of your pants feel out of driving but for the most part is increases the safety factor 10 fold.

I have personally tried on numerous toyota vehicles to get it sideways and unless you are going way too fast the car will save you every time.

The TLC/LX 4wd system has a mechanical (gear-based) center diff that does 50/50 split all the time. It does not vary torque like the 4runner/GX Torsen system. It does "give" when you turn a corner.

The Torsen center diff system in 4th gen 4runners (gear-based also; T-3 design) is better than TLC/LX's system ONLY in handling at high speed where a rear bias of torque is preferred. Torsen is basically the same as TLC/LX system except it can vary torque from rear to front depending on driving conditions. The ONLY time where Torsen may help is in high-speed cornering where the rear bias torque distribution will help handling and steering feel. For example, that is why BMW X5 sends more torque to the rear wheels, instead of 50/50. Same goes for most AWD sports car. This is to promote gradual oversteer, rather than understeer, which is important in handling.

However, for a 5500+ lbs of steel that is high off the ground, i don't see much benefit in the rear bias Torsen system. Maybe with the 4th gen 4Runners, Toyota is envisioning a more sporty truck. It is also a great advertising proclamation: "4Runner is the first SUV in it's class to have the Torsen center differential."

The Torsen center diff does NOT help in off-roading. In off-roading, you would lock the center diff most of the time, which will then distribute torque 50/50. And once the center diff is locked, both systems are equivalent. Remember, VSC turns OFF when you lock the center diff, but not A-TRAC.

Want more info on T-3 Torsen center diff on 4runner/GX? See this link:

http://www.torsen.com/products/T-3.htm

The A-TRAC system is the equivalent of having Limited-Slip Differential on both front AND rear axles...pseudo-LSDs. It is not going to be as efficient as a locker system front and rear (aka. ARB, Detroit's) over severe terrain (rock climbing, deep mud). But, then again, with ATRAC, you don't have to worry about turning the lockers on and off while off-roading. Because of A-TRAC, there is no more need to offer the rear locker option (for TLC) or LSD (for LX).

ATRAC actually does NOT transfer torque side to side as explained by Toyota brochure...it PREVENTS one wheel from losing total power.

More info, just check out my forum:

http://www.toyota-4runner.org/showthread.php?s=&threadid=12&perpage=15&pagenumber=1

Hope this helps.

Tinkerer said:

There is a sticker on my '99 LX rearend, near the fill hole, but it is mostly obscured by paint or undercoating; not readable, apparently not cleanable either.

But the window sticker and other info I have says "limited slip".

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If you've got a '99 LX then you've def got the LSD. I didn't notice the LSD sticker until I pressure washed my underbody after sinking it in the mud.

tabraha said:

sinking it in the mud.

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GROW UP!

tabraha said:

If you've got a '99 LX then you've def got the LSD. I didn't notice the LSD sticker until I pressure washed my underbody after sinking it in the mud.

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Uhhhh, sinking it in the mud is an understatement my man. What was the extraction method again??

The precise methodolgy is best described as:

Big Ass Massey Ferguson tractor.

Bill Burke would not have approved.

And John, I'm like Peter Pan when I see mud.