4x4 ok at high way speeds?
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guiltyxxspark
New member
I'd say unless you're actively trying to get out of a situation leave it in 2WD.
All the 4th Gen v8 4x4's are Full Time 4WD. All V6 4x4's have a "muilti-mode" transfer case.
Assuming you have a V6:
The Center Diff Lock is an independent function from 4WD in the transfer case.
In practice, this means putting the truck in 4x4 (the knob on the dash) does not lock the center differential... so you can do U-turns on dry pavement in 4 wheel drive without any issues (if you wanted to).
You would need to engage the center differential lock to "lock up" into part time, aka traditional 4x4 mode. Then you would not want to drive at highway speeds or do U-turns on dry pavement. Or be on dry pavement at all for that matter.
When unlocked, the center differential provides 60% torque to the rear axle, 40% to the front... hence the very RWD handling the trucks have.
In Full-Time Mode or in 2WD would likely have little impact on anything other than fuel economy. And supposedly, it has little impact on that too in most conditions. So if you've got it, use it. Further, cruising around ALL THE TIME in 2WD is not great for the transfer case. It has to be cycled in and out of 2WD/4WD, locked/unlocked, and HI/LOW Range constantly to keep it working properly. All those functions are independent on the V6, I believe.
My full-time V8 on General Grabber AT2s was significantly more capable on slippery highways than my friend's RWD Tacoma on true winter tires. Having the front axle engaged with the center differential open makes a universe of difference in stability.
Assuming you have a V6:
The Center Diff Lock is an independent function from 4WD in the transfer case.
In practice, this means putting the truck in 4x4 (the knob on the dash) does not lock the center differential... so you can do U-turns on dry pavement in 4 wheel drive without any issues (if you wanted to).
You would need to engage the center differential lock to "lock up" into part time, aka traditional 4x4 mode. Then you would not want to drive at highway speeds or do U-turns on dry pavement. Or be on dry pavement at all for that matter.
When unlocked, the center differential provides 60% torque to the rear axle, 40% to the front... hence the very RWD handling the trucks have.
In Full-Time Mode or in 2WD would likely have little impact on anything other than fuel economy. And supposedly, it has little impact on that too in most conditions. So if you've got it, use it. Further, cruising around ALL THE TIME in 2WD is not great for the transfer case. It has to be cycled in and out of 2WD/4WD, locked/unlocked, and HI/LOW Range constantly to keep it working properly. All those functions are independent on the V6, I believe.
My full-time V8 on General Grabber AT2s was significantly more capable on slippery highways than my friend's RWD Tacoma on true winter tires. Having the front axle engaged with the center differential open makes a universe of difference in stability.
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BackOff
New member
You can run it in 4wd HIGH, fine at speed. DONT lock the center diff lock on the highway.
I had mine in 4x4 for over 3 months last winter...tons of that awful cold white stuff. MPG will go down.
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simple
Senior Member
I have driven 500mi in terrible weather at highway speeds in my old V6 04 and not a single issue. I also had a 2015, which is true 4wd with locked center diff, and have driven that at high ways speeds in 4wd. The trick is not turning, as when the center diff is locked all the wheels are locked at the same speed. When you turn the wheels begin to turn at different speeds, and if they’re locked it creates binding in the dif. A good rule of thumb I once read on the 5th gen forum is any turn you can make at greater than 30mph should be ok. And from my experience in my 5th gen, that was solid. If there was binding, I could feel it release when I shifted back into 2wd, and didn’t have any issues adhering to that rule of thumb.
But as others have mentioned, this isn’t a concern in the 4th gen, unless you lock the center diff.
But as others have mentioned, this isn’t a concern in the 4th gen, unless you lock the center diff.
:thumb3: This is why the 4th gen setup is superior to the 5th gen setup. Can't run 4WD with an open diff on the 5th gens. Unless you have the Limited full-time 4WD, which can be open or locked. But then you don't have 2WD.
Yes, the center differential lock should be a separate button (left of the steering wheel). The center diff is open and automatically works as AWD when not pressed (you can drive on hard surfaces without problems). Press the center diff button for a few seconds and you will see a different 4wd symbol in you dash (I wouldn't use the locked mode for highway driving as you loose VSC).
2WD, 4Hi, 4lo is the round selector dial sitting by the stereo (to the right of the steering wheel). This controls whether the front wheels get engaged and or lower gears.
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Wow, it’s all making sense now. I’m pretty sure i read about that button when i first bought it but didn’t quite understand. I noticed how smoothly it turned at slow speeds compared to other trucks I’ve had in the past, you kind of get the front wheel hop when making sharp turns in 4x4.
Thank you guys very much for the info and your time!
Jeff
Thank you guys very much for the info and your time!
Jeff
Bumbo
New member
Which also makes it no different than the V8 4th gen... minus the V8 part lol.
Say that on the 5th Gen forums and everyone will tell you that there is no use to being able to run AWD on the pavement, or what it isn't a "big deal", or what it provides little benefit. Guess the Pro, Trail, SR5 are in denial.
That said... The Torsen center TC is the main reason I went with a Limited on the 5th Gen. I would have preferred a GX just for the V8 if the front grill didn't look like womens underwear.
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JB.
New member
Always a good idea. There's a mechanical component to all of them but initiation in all is electronic.
When you're in full time 4wd you can hit the diff lock button while driving straight anytime you like. Doesn't even have to be perfectly straight, either. A small amount of steering wheel turn won't prevent it from smoothly engaging. Should go in and out quite easily.
Yes. And there is a thread here that people post monthly as a reminder to engage and disengage the 4x4.
yeah, as others have mentioned above it is a necessity to use the 4WD features to keep it working properly.
Heck, last time I was in low range with the center diff locked was September!
In the V6:
If I recall, the front drive train is engaged by a solenoid operated sleeve that rides on the output shaft of the transfer case. Engaging the front drivetrain slides the sleeve into place on the splined shaft to "pick up" the front drive train and cause it to spin with the powered drive train. All this happens in the transfer case... I'm not sure if the 4th gen V6 has the electronically disengaging drive train like the 99-02 3rd gen (early version was vacuum operated I think).
Anyway, if it does, engaging the 4WD on the V6 makes that splined sleeve slide into place too; and that links both front half shafts to the differential. Without that sleeve in place, one half shaft isn't powered (and the stub end of the axle out of the front diff, on the side with the actuator, spins freely).
Anyway, what I'm dancing around getting at is that these sleeves have tight tolerances to the splined shafts they ride on. A little bit of gunk on the splines can cause it to jam or fail to engage. Either scenario is a maintenance nightmare.
The V8 doesn't have any 2/4WD settings to deal with... it's all permanent 4WD and always engaged. Just need to worry about HI/LOW and Lock/Unlock.
I really love the drivetrain on the V8 4th gen. It's beautiful.
My dad has an 04 V8 4 runner and recently dropped close to $3k on getting repairs as the 4w LO no longer worked as he forgot to engage it.
I make it a point to engage everything once a month myself. I try to limit the LO to a short city block on low speeds but I'm wondering if even that is too much?
I make it a point to engage everything once a month myself. I try to limit the LO to a short city block on low speeds but I'm wondering if even that is too much?
No problem going as far as you want in 4LO as long as the center diff is unlocked, and you don't mind going slow. 30-35 mph is about the practical limit, although you can go faster for short distances. But, if you keep the speed down, you can drive from Maine to California without hurting anything. Gas mileage will be pretty bad, however.
Heffernan
Member
Apologies for bumping an older thread, but I wanted to confirm that I have my information correct.
For my v6 as follows:
1. 2Hi is for normal, everyday, low or high speed, driving (duh)
2. 4Hi (w/ center diff unlocked) acts as AWD and can be driven on dry pavement (if wanted) at normal speeds, with turns, with no worry of damage.
3. 4Hi (w/ center diff locked) is to be used when more traction is needed, slightly higher speeds but shouldn't be used on dry pavement and limits the amount the vehicle can turn (should only be used in more or less straight lines)
4. 4Lo (w/ center diff unlocked) slow speeds only, but you can still turn the vehicle without worry of binding.
5. 4Lo (w/ center diff locked) slow and straight, only.
Any corrections I should know of or does this sound right?
For my v6 as follows:
1. 2Hi is for normal, everyday, low or high speed, driving (duh)
2. 4Hi (w/ center diff unlocked) acts as AWD and can be driven on dry pavement (if wanted) at normal speeds, with turns, with no worry of damage.
3. 4Hi (w/ center diff locked) is to be used when more traction is needed, slightly higher speeds but shouldn't be used on dry pavement and limits the amount the vehicle can turn (should only be used in more or less straight lines)
4. 4Lo (w/ center diff unlocked) slow speeds only, but you can still turn the vehicle without worry of binding.
5. 4Lo (w/ center diff locked) slow and straight, only.
Any corrections I should know of or does this sound right?
Berty_K
Member
You're mostly correct. Key thing for you to note: never engage the center diff on a dry surface. Sure, you can drive in a straight line, but why risk binding and stressing the drive train? Just find a loose surface to drive on.
As long as the center diff is not engaged, you can drive in 2Hi, 4Hi, or 4Lo on dry surfaces.
