2009 Limited V6 Muilti Mode 4wd Rear Diff not limited slip ?

[JCSTEW]

From what I understand a 2wd only 4runner would have a limited slip differential on the rear. If you have a SR5 4runner or a Limited 4runner with a V6 with multi mode 4wd in 4H mode it utilizes center limited slip differential called Torsen. This system would be the same on a 4runner limited with a V8 and no option to have 2wd. So what happens when you put the multi mode in 2wd on the V6 limited or a V6 SR5 ? The center limited slip Torsen Diff is no longer in play and you are left with a 2wd 4runner with a rear diff with no limited slip differential. Is this correct ? The rear diff with a multi mode 4wd that has 2wd mode just has a basic rear differential. As an aside I don't have the optional electronic locking rear diff option. Is the above correct ?

 

[kevinpt]

From what I understand a 2wd only 4runner would have a limited slip differential on the rear. If you have a SR5 4runner or a Limited 4runner with a V6 with multi mode 4wd in 4H mode it utilizes center limited slip differential called Torsen. This system would be the same on a 4runner limited with a V8 and no option to have 2wd. So what happens when you put the multi mode in 2wd on the V6 limited or a V6 SR5 ? The center limited slip Torsen Diff is no longer in play and you are left with a 2wd 4runner with a rear diff with no limited slip differential. Is this correct ? The rear diff with a multi mode 4wd that has 2wd mode just has a basic rear differential. As an aside I don't have the optional electronic locking rear diff option. Is the above correct ?

if you used the search function you could find your answers without having to make new threads.

as far as i know all 4th gens are open diff with the option of a locking rear on the trail in 09. the only limited slip like ability in the 4runner is by use of the traction control. its not as smooth as a limited slip but toyota seems to like this and i really dont know why.

 

[JCSTEW]

Thank you for your input. As for searching for this thread I did and I did not really find the answer I was looking for. In fact many techical posts I have found did not explain the 2H operation of a 4runner with the the multi mode 4wd system. Maybe the answer is obvious one but I have yet to actually get that answer. You have clarified something though. If you put the 4runner in 2H mode technically the traction control system must be defeated unless the the the 4runner ignores the 2H setting which I have not found this to be the case. The VSC may still work to some degree but traction control really can't work in 2H mode. The obvious part. One drive shaft delivering power to an open diff mechanically can not have traction control. If in 4H mode traction control is then possible through the limited slip center diff when it is not locked. As an aside if you lock the center diff you then have the old time 4wd or the part time 4wd you have on a Tacoma or Tundra. Not the case with 4runner or Sequoia. I am willing to bet that you are one of the few that understand how the multi mode drive system actually works. Even Toyota Sales and Service reps don't appear to know how this system works or any other variations of 4wd that Toyota sells. Toyota does have an animated set of training slides that I believe I down loaded off of this forum some time ago. Maybe I need to revisit those slides to see if I missed the part about how the open diff works when you are in 2H. Does your 09 limited have a V8 ? If it does you would not have the 2H mode of operation. In 09 the limiteds with a V6 had the 2H mode. Thanks for all your help.

 

[m85476585]

• 2WD only 4runners have open rear diffs
• If you put a 4WD 4runner on 2WD mode, it's exactly the same as a 2WD 4runner, in terms of which wheels get power
• The center limited slip diff is completely mechanical, so it assists traction control, but it is not traction control
• 2WD-only 4runners have "Auto LSD" mode which uses the brakes to electronically simulate a LSD. Basically it brakes one wheel if it looses traction and starts slipping so that the power goes to the other wheel
• 4WD 4runners have traction control, also called TRAC or ATRAC. That basically does the same thing as Auto LSD, even though it is called something else. It works on all four wheels, unless you are in 2WD mode then it probably works like Auto LSD, but I'm not sure.
• VSC is mostly independent of traction control, diffs, engine power, etc. It brakes individual wheels to keep the 4runner going in the direction you point the steering wheel.
• All these things use the same actuators to pulse the brakes, and although there are separate modes or names, it's really all one system that does VSC, TRAC, ATRAC, ABS, EBD, Brake Assist, HAC, DAC, etc.