Transfer Case Question

[Martinjmpr]

Doesn't seem like any kind of hassle, does it?

No, because only an idiot or somebody who didn't know how to drive in the snow would do that. Shift into 4wd to cross the hump of snow left by the plow?

Seriously?

Do you not realize that lots of people drive in snowy conditions every single day in 2wd vehicles and don't get stuck?

Here's how it actually goes:

Start vehicle. Snow/ice on the street?

Yes: Shift into 4wd
No: Keep it in 2wd.

Drive to work. Turn off engine.

It's not that hard, guys. :

 

[Martinjmpr]

Anyone can make a conventional 4x4 (for offroad) or even AWD. But how many have been able to create a system that will allow you to go back and forth between 2wd and 4wd in whatever driving conditions while giving you fulltime 4wd capability?

I know the Mitsubishi Montero Sport from the late 90's had such a T-case, as did I believe several domestic brands. Really the 2wd/4wd/AWD t-case isn't all that unique. My guess is that market research showed that the feature wasn't really considered to be that great and it was dropped as a cost saving measure.

 

[chip4]

Regardless, It doesn’t mean isn’t that great, it is a very capable system which may surpass current part time systems are far as functionality in different environments, and the fact that its used rarely on 4wd vehicles today makes it unique.

 

[nighthawk]

Does this mean that the 3rd gen SR5's have this same issue where you can't drive it in 4WD on dry pavement?

 

[Martinjmpr]

Does this mean that the 3rd gen SR5's have this same issue where you can't drive it in 4WD on dry pavement?

If it's an 01 or an 02 it has the Torsen center diff with the lock switch on the dashboard, so you can drive in 4wd on dry pavement. But the 01 and 02 also added the VSC and deleted the locking diff option, so no rear locker (in fact, I think the location of the center diff lock switch is the same place that the rear diff lock switch is on the earlier 4runners.)

The limiteds in 99 - 2000 were available with both the locking diff and the torsen center diff. SR5s from 96 to 2000 and Limiteds from 96 - 98 just have the conventional 2wd/4wd part time system that is found on the Taco.

 

[JB.]

I know the Mitsubishi Montero Sport from the late 90's had such a T-case, as did I believe several domestic brands. Really the 2wd/4wd/AWD t-case isn't all that unique. My guess is that market research showed that the feature wasn't really considered to be that great and it was dropped as a cost saving measure.

It's the full-time with the Torsen that's the biggie. Others have had full-time with open diffs or viscous couplers.

 

[JB.]

If it's an 01 or an 02 it has the Torsen center diff

No 3rd gen had a Torsen center.

 

[adkinsadam1]

What is the point of 4WD on dry pavement anyway?

 

[Climb14er]

No, because only an idiot or somebody who didn't know how to drive in the snow would do that. Shift into 4wd to cross the hump of snow left by the plow?

Seriously?

Do you not realize that lots of people drive in snowy conditions every single day in 2wd vehicles and don't get stuck?

Here's how it actually goes:

Start vehicle. Snow/ice on the street?

Yes: Shift into 4wd
No: Keep it in 2wd.

Drive to work. Turn off engine.

It's not that hard, guys. :

I've been living in Colorado, driving the snowy mountain roads, venturing out on 'real' off-roads and the old part-time 4WD that Toyota is returning is OLD SCHOOL! The factory is CUTTING BACK the costs and reverting back to old school technology.

The 4WD Torsen system in the 4th generation, the factory could easily have kept. They chose to revert back to an archaic system that was good in the early 90's but it's now 2010 and out-dated.

It's not that the factory didn't have the Torsen already in! They did and everyone was content.

Thinking that the old system is fine...well, not for this guy who for thirty five years has experienced both extensive dry and wet pavement on the same road virtually at the same time and the 4WD Torsen is ideal. The part-time is a pain in the you-know what!

They lost me as a new buyer of the 2010's. I will wait for the V8 and the Torsen to both be returned. If not, my cash is going elsewhere.

Money talks... Toyota factory b.s. walks! :beer:

 

[jh26]

If it's an 01 or an 02 it has the Torsen center diff with the lock switch on the dashboard, so you can drive in 4wd on dry pavement.

I'm pretty sure the full-time system in the 3rd gens was an open-diff in the center, not torsen. I've owned both and the Torsen is noticeably nicer, but the open-center does the trick too.

 

[M1911]

What is the point of 4WD on dry pavement anyway?

As I posted earlier in this thread:

Here in the Northeast we get snow in the winter. You are often going from dry pavement to wet pavement to partly snow covered to full snow covered in just 1/4 mile or so. You can't drive on dry (or even wet) pavement in part-time 4WD -- you'll bind up the drivetrain. You can drive in a full-time 4WD vehicle in such conditions.

Furthermore, when you are on a snow covered road, a part-time 4WD vehicle with no center diff has the front and rear diffs turning at the same speed, which results in slip when going around corners. A full-time 4WD vehicle with a Torsen center diff allows the front and rear diffs to turn at different speeds, resulting in better traction in the snow.

 

[TRDSmokedU]

with you all the way. i'll be writing letters to Toyota expressing my dissatisfaction.

This is exactly what I did. I email them expressing my dissatisfaction with the lack of a V8 and the ugly mast style antenna. I like the new looks, but wish they would have done a nicer looking dashboard. If you are unhappy, please let Toyota know. They e-mail me back saying they need to hear what customers have to say. Obviously, they are not going to tell us future information, but if enough people e-mail them about the lack of V8 as well as the lack of the multi-mode 4WD, they may bring them back. Toyota makes a lot of chances to their vehicles during their life cycle. We all remember the ugly plastic fenders on the first 4Runners.

 

[M1911]

We all remember the ugly plastic fenders on the first 4Runners.

Yup. Did they go away in 2004, or was it even before that, mid model year 2003?

 

[J.A.]

I'm pretty sure the full-time system in the 3rd gens was an open-diff in the center, not torsen. I've owned both and the Torsen is noticeably nicer, but the open-center does the trick too.

Correct

4th Gen VF4AM, VF4BM = Torsen LSD
3rd Gen VF3AM (1999LTD, 2000LTD, 01, 02) = Double Pinion Planetary

 

[adkinsadam1]

Wait I am totally confused. Would you say that PART TIME 4WD is better for off road conditions with rocks and boulders and FULL TIME 4WD is better for snowy conditions primarily? Is that thinking correct? And what is better for off-roading, Live axle like in the 5th gen or individual suspension like in the 4th gen?

And wait!!!!! So part time 4wd in 4wd mode is just like full time 4wd with the center diff locked, right? Well then how come in the videos of the 4runner trail on the rubicon when some wheels are suspended, some wheels are spinning while others are not? And if it is just like I thought, than why do you need locking rear differentials at all?

 

[M1911]

Wait I am totally confused. Would you say that PART TIME 4WD is better for off road conditions with rocks and boulders and FULL TIME 4WD is better for snowy conditions primarily? Is that thinking correct? And what is better for off-roading, Live axle like in the 5th gen or individual suspension like in the 4th gen?

No. The full-time 4WD with a locking center diff is better in snow conditions and is just as good a part-time 4WD system off road.

Both the 4th gen and 5th gen have the same suspension types: IRS front and live axle rear. No difference.

And wait!!!!! So part time 4wd in 4wd mode is just like full time 4wd with the center diff locked, right?

Yes.

Well then how come in the videos of the 4runner trail on the rubicon when some wheels are suspended, some wheels are spinning while others are not?

Because the front and/or rear diffs were not locked. The front and rear diffs transfer torque side to side. The center diff transfers torque front to rear. The only way that all tires would be spinning at the same rate is if all three diffs were locked -- front, center, and rear. Very few vehicles have three locking diffs, and it is very difficult to turn with all diffs locked. It is also easier to break things with all diffs locked.

And if it is just like I thought, than why do you need locking rear differentials at all?

Because ATRAC transfers by using the brakes. Locking the rear diff is far superior.

 

[adkinsadam1]

VERY helpful m1911!

 

[gaberelli]

One of the best features of the 4Runner was its 4WD system. Gone is the versatility of a 2WD/AWD-HI/AWD-LO/4WD-HI/4WD-LO system that couldn't be matched. Add a rear diff lock (i.e. 2009 Trail Edition) and you are set!!! I will be looking in the used market for my next 4Runner. Email to Toyota sent!

 

[adkinsadam1]

M1911
OK OK OK, so you're saying that without the differentials locked in part-time 4WD, the wheels can spin separately, correct? Well then how is that any different from full-time 4WD?

 

[M1911]

M1911
OK OK OK, so you're saying that without the differentials locked in part-time 4WD, the wheels can spin separately, correct? Well then how is that any different from full-time 4WD?

Most part-time 4WD do not have a center diff. Thus the front and rear driveshafts turn at the same speed. When you turn a corner, as you know, the rear of your car is closer to the apex of the corner than the front of your car. That is, the front takes a wider corner than the rear. Since the rear is traveling a shorter distance, the rear driveshaft must turn a smaller number of turns than the front driveshaft. With a part-time 4WD, it can't do that unless the wheels slip. If the wheels can't slip, then you put extra stress on the driveline. That is why part-time 4WD can not be used on dry roads.

In contrast, the Torsen limited slip center diff on the 4th gen 4Runner, when unlocked, allows the front and rear driveshafts to turn at a different rate, so you can go around a corner without the drivetrain binding up. The limited slip ensures that some torque goes to each axle.

Now, if you are in a low traction situation, a part-time 4WD system with no center diff will make the front and rear driveshafts turn at the same rate. If you have a Torsen center diff and you lock the center diff in this situation, then it will behave the same. Note, however, that even if the front and rear driveshafts are turning at the same speed, that doesn't mean that the right and left front (or rear) tires are turning at the same speed. The front and rear diffs allow the left and right tires to turn at different rates -- that is what lets you turn a corner.

The center diff (or lack of center diff on a part-time system) only controls the distribution of torque from front to rear. They do not affect the distribution of torque from right to left. So if both right side tires were on ice, but the left side tires were on pavement, you still might not be able to move. That is where the ATRAC system comes in, or a locking rear diff. The ATRAC system distributes torque using the brakes. The locking rear diff ensures that both rear wheels turn at the same speed.