Is the 4runner Trail Edition Too Complex??
- Thread starter Thai
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Thai
Elite Member
It takes more than just a "weee" to make the conversion...if you want to do it right in terms of ride comfort and durability.
Once they actually test drove it, Toyota sure would lose sales. A solid front axle gives much worse handling, ride, and tracking. The IFS is more than enough for 99.9% of 4Runner owners. If you really are that into rock-hopping that you need a solid front axle, the 4Runner is too big for you anyways.
dwulffusa
New member
On a simpler note, I guess that's why the 5th gen Limited is 4H unlocked, 4H locked and 4L locked. So the manual probably reads, just turn the knob until you're free. If you're in in 4L locked, call a tow truck.
On a 4th gen V6 4WD, got stuck in 2H. Try 4H, still stuck. Now should one stay in 4H and go locked, or be in 4L unlocked? Still making no progress. Unlock and go to 4L, or stay locked and go to 4L?
Choices are good, but for the everyday driver and non-enthusiasts it's just confusion.
Well I just thought if something that may be very relevant in an offroad situation. I havnt driven a vehicle with a manual transfer case in almost 20years. (there's irony in that...).
But when you stop, engage, and pull away its immediately activated right?
If so, that makes this system more appropriate for a vehicle intended to be used in real offroad conditions.
Well on the electronic engagement on the 4th gen I sometimes drive up to 50yards with the light blinking (when shifting from 2HI to 4HI, 4HI to 4LO is immediate) before it engages. I find this very frustrating, how often do you have this much room when offroad to coax a system to engaging? I need at least 5-10yards with the wheels straight to engage the center lock. What happens if you dont anticipate a certain situation, you are already stuck? It wont engage just by spinning the wheels right? What do you do?
Or is there something wrong with my system? Dealer says there is not, and it waits for 'a whole lot of variables to be in sync' before engaging.
Could this be a reason for going to a manual transfer case in the Trail?
Thai
Elite Member
Exactly. I mentioned this in another thread. The Part-time system is a GOOD THING off-road. The 4wd engagement is immediate and solid. Less parts altogether and less parts to break. Sure, it is not as good for the folks in the snowbelt, but for off-roading, the part-time system is more reliable and durable. (BTW, my Mercedes has a center diff too...so, i am not being bias here.) :driving:
And yes, your system is normal.
gm350reratliff
New member
Too complex? Short answer-yes.
Thai
Elite Member
4th gen has the multi-mode 4wd system on the V6 model and full-time 4wd on the V8. The multi-mode 4wd system has a center differential...it allows for 4wd useage on dry land.
dwulffusa
New member
This takes me back to a question about the center diff lock which I dont think I posed correctly. I understand how a rear diff lock works.
My question is, what is the benefit of a rear locker in addition to the center lock on an 09 Trail?
I ask this because in 4HI or 4LO in my 4th gen, if you take grip away for 2 diagonally opposed wheels, or suspend them completely, they will spin. With the center diff locked, they will not. At least I have never experienced a situation where there is any slip with the center diff locked. Its easy enough to understand a schematic on how rear lock works, but I cant get my mind around how the center lock and front and rear axles/driveshafts are connected. (I am not asking you to try and explain!, If you have a link, pls send).
But what is a situation that a rear diff lock would help, where a center lock would not?
Thai
Elite Member
Center diff lock = locks the front and rear axle together; thus, torque flows to the front and rear axle equally. (Coincidentally, it also shuts off VSC.)
On the 4th gen, you have a Torsen center differential. It allows for torque to go to the front and rear differential on dry land. However, how much of the torque to each axle varies upon road conditions. Sometimes, it will send 70 percent of torque to the rear axle (and 30% to the front)...such as when you turn on a curve in the road. Other times, it will send 60% of torque to the front axle (and 40% to the rear)...such as when one of the tire in the rear axle is slipping. Yet, other times, it will send 50%/50% to each axle when you're driving straight.
However, in off-road conditions, you do not want the computer to think too much...you do not want it to shift power to either axle when you don't need to. In addition, the Torsen center diff has a nasty habit of sending ALL power to the wrong axle IF both tires on one axle has lost complete traction. So, if your rear axle is sunken in deep mud and has no traction whatsoever, then the Torsen will INcorrectly send all power to the rear axle...thus, you're stuck. This is why LOCKING the Torsen off-road is a good thing...to prevent such issue and to take the ECU (computer) out of overthinking itself. (As noted above, locking the center diff will also turn OFF stability control, which tends to de-throttle your engine when it encounters slippage.)
Back to your original question. I think that it is coincidence that you see less slippage with the center diff locked. Center diff only controls power flow to the front and rear axle. The power flow laterally (left and right) on EACH axle is controlled by the traction control system (ATRAC). Therefore, in your diagonally suspended 4runner, it is the ATRAC that makes the most difference in slowing down the wheels that are in the air and shifting power to the wheels that are on the ground. The locking center diff is just there to guarantee that each axle will have 50% of engine torque for ATRAC to shift power left and right. BTW, for ATRAC to work its magic, there MUST be some slippage...because the wheel sensors (via ABS logic) MUST sense wheel speed differences between the wheels on the SAME axle for it to engage.
In other words, if your 4runner did NOT come with ATRAC and has totally open differentials front and rear, then you would be stuck in the diagonal situation you described, regardless of whether your center diff was locked or not.
A rear locker is good off-road because, in your diagonal situation, the rear axle tires do NOT have to wait for slippage for both tires to get power. Lets concentrate only on the rear axle. With ATRAC controlling the rear axle, there must be slippage (from the tire suspended in air) before ATRAC will slow that tire down. This will then allow SOME torque to flow to the other tire on the rear axle that is touching the ground. So, there will be a moment of slippage before you see any power flowing to the other tire. A rear locker locks the two rear wheels together. Therefore, both tires are ALWAYS getting 50% of torque that is being sent to the rear axle via the center diff. There is no waiting for one tire to slip before the other gets power...both tires ALWAYS get power. Thus, in your diagonal situation, there won't be any hesitation (or waiting) before your 4runner will move forward. This is why a locker is superior to ATRAC under most off-road conditions.
In summary, a center diff lock does NOTHING to the torque flow between your left and right tires. Its only job is to make sure that power flows to both front and rear axles equally (north and south)...and that VSC (stability control) does not take power away from you. ATRAC is what controls the power flow between your left and right tires on each axle via pulsating the brakes on the slipping wheel (east and west)...it requires tire slippage before it will direct power to the proper tire. A locker does the same thing as ATRAC but it does not require tire slippage before it engages...it is always sending power to all tires on the same axle that is being locked down.
Hope this helps in some way...sorry if i went a bit off-topic.
The Trail Edition doesn't have a manual transfer case. The "lever" on the 5th gen SR5 and Trail is just connected to a switch -- it isn't a mechanical linkage directly connected to the transfer case itself. In operation, it works no differently than the switch on 4th gen 4Runners, and the behavior will be the same. That is, it may take rolling back and forth to get into 4WD on the 5th Gen, just like on the 4th Gen. So put it into 4wd before you get into trouble.
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Thai
Elite Member
Is this a fact or something you're guessing?? Have you actually done this action on a 5th gen?? The center diff takes a while to engage because the gearset teeth has to line up before the front and rear axles are linked. This should not be the case with the part-time 4wd system, whether it is electronically-linked or mechanically-linked. On a part-time 4wd system, there is nothing to line up for the 4wd to engage...it should instantaneous! My brother's 2008 FJ's part-time system engages 4wd instantly. Remember, to shift into 4wd on a part-time 4wd system, you have STOP and shift into NEUTRAL before you can engage 4wd with the lever. How can you roll back and forth while in Neutral??
Is this a fact or something you're guessing?? Have you actually done this action on a 5th gen?? The center diff takes a while to engage because the gearset teeth has to line up before the front and rear axles are linked. This should not be the case with the part-time 4wd system, whether it is electronically-linked or mechanically-linked. On a part-time 4wd system, there is nothing to line up for the 4wd to engage...it should instantaneous! My brother's 2008 FJ's part-time system engages 4wd instantly. Remember, to shift into 4wd on a part-time 4wd system, you have STOP and shift into NEUTRAL before you can engage 4wd with the lever. How can you roll back and forth while in Neutral??
Here's the video using the 4WD shifter. As it states, switching from 2WD to 4WD is on the fly, switching from 4WD to 4WD Low is stop/neutral/shift.
JAC
New member
If you guys that are used to all this offroading thing are debating about this...I can't imagine someone new to offroading buying and trying to figure out how to offroad with the TE....... I'll be completely lost surrounded by so many knobs and controls and different modes of driving the 5th gen TE. I am gonna feel that I am getting ready to fly a spaceship or something.
I love it tho'.... So definitely I am coming back to this thread to find out things If I ever buy m one.
I love it tho'.... So definitely I am coming back to this thread to find out things If I ever buy m one.
Thai
Elite Member
You're right. My mistake. However, my brother confirmed it...the shift into 4wd is quick and smooth for the most part. On rare occasion, 4HI would not engage and you just have to wait a second before trying again.
The point that I was trying to make is that there is no difference in that behavior between the 4th gen rotary switch and the 5th gen "lever." The 5th gen lever isn't directly connected to the transfer case. It is just a switch, like the switch on the 4th gen, with all the same issues.
JB.
New member
Hmm...that brings to mind an interesting point. With the 4th gen you can run the trail in 4WD and then lock and unlock the center diff on the fly and when exercised, it locks and unlocks quickly and easily. I think that more than offsets the part-time advantage of shift speed, when stopped.
I think you are wrong about this. I test drove an SR5 and found that the transfer case lever actually moved and vibrated under load, which leads me to believe it is directly tied into the transfer case through linkage.
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