Another 4 Wheel Drive Question

[Blitzkrieg]

About 10 years ago my friends wife's father who used to own a Ford dealership and his wife and he had own of those huge like $200k super deluxe RV's.

They were getting ready for an extended cross country trip and he bought a brand new Ford pickup to tow behind the RV.

They made it the 700 miles or whatever to their first stop and oh boy. He had left the transfer case in drive and the manual tranny in gear.

The way I remember it completely fried the entire drive line including the motor. Truck had like 110 miles on it. Insurance fought him on it because he was towing it, not driving it. I think eventually they gave in.

Now THAT'S a boo boo of epic proportions.

Me, I just mine a straight road and stick it in 4HI for 10 minutes once in a while. I've done that with every part time 4WD I have owned and never hurt a thing.

 

[grumpy514]

I honestly would never put the car in 4H on dry pavement, even on wet payment I wouldn't really trust it. I used 4H when there was snow just about completely covering the road. I would try to find a grassy area or somewhere semi offroad to just engage the 4WD somewhat, doesn't have to be anything serious to get it lubed.

 

[1engineer]

In 4lo there is more torque applied to the drive line. It isn't uncommon to be spinning tires, or for a tire to be spinning in the air, then abruptly regain traction. You are also likely aired down and your tires have far more grip at 12psi than at 40.

On slick rock, you feel binding and tires bark loudly, often.

Does anyone think having it in 4WD and turning on dry pavement puts more stress on the drive line than this http://www.toyota-4runner.org/5th-gen-t4rs/155746-bimrunner-build-thread-pics-25.html#post2047905 ?

 

[Jetboy]

I put it in 4wd when I think it might be slippery. Take it out when it's not. Pretty simple. I have no qualms about running in 4wd on dry pavement. Not even remotely close to what it sees offroad.

I've never been able snap an axle shaft, a drive shaft, or a transfer case output on dry pavement. Done all of them a few times offroad. I think most folks who don't go off-road much would be pretty surprised by how much abuse these vehicles can withstand and how minimal the stress is from a typical drive in 4wd on dry pavement in comparison.

 

[1engineer]

I put it in 4wd when I think it might be slippery. Take it out when it's not. Pretty simple. I have no qualms about running in 4wd on dry pavement. Not even remotely close to what it sees offroad.

I've never been able snap an axle shaft, a drive shaft, or a transfer case output on dry pavement. Done all of them a few times offroad. I think most folks who don't go off-road much would be pretty surprised by how much abuse these vehicles can withstand and how minimal the stress is from a typical drive in 4wd on dry pavement in comparison.

Exactly.

 

[jwkilgore]

I put it in 4wd when I think it might be slippery. Take it out when it's not. Pretty simple. I have no qualms about running in 4wd on dry pavement. Not even remotely close to what it sees offroad.

I've never been able snap an axle shaft, a drive shaft, or a transfer case output on dry pavement. Done all of them a few times offroad. I think most folks who don't go off-road much would be pretty surprised by how much abuse these vehicles can withstand and how minimal the stress is from a typical drive in 4wd on dry pavement in comparison.

It's not about the stress on the vehicle (although that does exist), is when you are going around a sharp curve on dry pavement too fast and suddenly some of your wheels start slipping because the system is bound up. It could throw you out of control.

This generally isn't as much of a problem on slicker (snow, dirt, wet, etc) roads because generally you won't be driving as fast.

 

[Antman]

does anyone think having it in 4wd and turning on dry pavement puts more stress on the drive line than this http://www.toyota-4runner.org/5th-gen-t4rs/155746-bimrunner-build-thread-pics-25.html#post2047905 ?

 

[Engineer]

View attachment 163368

Please stop posting photos of [MENTION=47340]Titanpat57[/MENTION] and yourself. I don't know the backstory, don't need to or want to. While this is a public forum there are some expectations that only certain members are allowed to violate (@Stifler) please keep your posts technical as that is were you excel. :focus:

Edit: To stay on topic, OP, Find a parking lot or low traffic area when the pavement is dry, put the 4runner into 4wd hi and go drive around, straight lines, sharp turns, smooth curvy turns, etc. You will experience driveline bind and wheel skipping/hopping but then you will know exactly what it feels like, it is unlikely to do any damage to the 4runner unless you are doing highway speeds and sharp turns (at which point I bet the 4runner rolls before you break anything in the drive train but who knows) or trying to do donuts while in 4L on dry pavement (even then I wouldn't expect damage but I wouldn't do it!).

Next step, now that you have 1st hand experience you can drive in 4Hi while on dry pavement and know what situations to avoid to prevent binding/hopping. I use 4hi on wet pavement and have used it in dry pavement on the relatively strait highway when it had been awhile since I actuated the system the 4runner is fine as I will take it out of 4wd if I need to make sharp turns etc.

As others have mentioned, your 1st experience on the slick rock (more like 120grit sand paper) in Utah and you will find there are plenty of times when the driveline binds just from trail driving.....already miss that slow chirping sound....need to go back soon

 

[Jetboy]

It's not about the stress on the vehicle (although that does exist), is when you are going around a sharp curve on dry pavement too fast and suddenly some of your wheels start slipping because the system is bound up. It could throw you out of control.

This generally isn't as much of a problem on slicker (snow, dirt, wet, etc) roads because generally you won't be driving as fast.

Have you ever actually had this happen? I haven't. I think you're going to end up on the roof long before you lose control on dry pavement. I've often heard the same thing about locking differentials - from people who've never driven at highway speeds with locked differentials. I have never experienced this. It just doesn't actually happen. Not in 4wd, not with locking differentials, not on dry pavement, not on ice. It might cost you a few seconds on the 'ring - I don't think it's causing any meaningful safety issues in normal driving.

 

[Antman]

please stop posting photos of [mention=47340]titanpat57[/mention] and yourself. I don't know the backstory, don't need to or want to. While this is a public forum there are some expectations that only certain members are allowed to violate (@stifler) please keep your posts technical as that is were you excel. :focus:

 

[msp]

I'd like to remind everyone that this thread ended at post #20. Do keep the pictures coming, I'm still stuck at work and need the entertainment.

 

[wanderMT]

It's all the big assed tires giving binding problems:drum:

 

[Steamtrain]

I now have the strange feeling of not adhering to the manual and changing my oil every 3,000 miles.
:brushteeth:

 

[jwkilgore]

Have you ever actually had this happen? I haven't. I think you're going to end up on the roof long before you lose control on dry pavement. I've often heard the same thing about locking differentials - from people who've never driven at highway speeds with locked differentials. I have never experienced this. It just doesn't actually happen. Not in 4wd, not with locking differentials, not on dry pavement, not on ice. It might cost you a few seconds on the 'ring - I don't think it's causing any meaningful safety issues in normal driving.

I have experienced binding on dry pavement which affected my steering in a sharp turn, yes. I wasn't going fast enough to lose control, but I understand the physics of how it could happen.

Just out of curiosity, what would you call "end up on the roof" if you don't consider that losing control?

 

[Jetboy]

I think you have so much lateral traction that you'll roll over before you'll notice any loss control and spin out. FWIW just for you I put my 4runner in 4h and drove home today. I went 80mph on asphalt at 100*. Did some tight corners in my neighborhood. A little steering stiffness, otherwise business as usual.

 

[jwkilgore]

I'm not talking about sweeping 4-lane curves or sharp turns at slow subdivision speeds. Toyota recommends against it, but I can't see how you can get hurt or break anything doing it. Knock yourself out.

Something I did last year was take 4WD-only Pearson's Branch Road out of Cade's Cove, then drive way too fast down the Tail of the Dragon (I drove sports cars and motorcycles in a previous life phase). I took it out of 4H when I hit pavement. Driving fast around hairpin curves requires good control, especially in a high-gravity 4WD. Trying to max out speed when the steering wheel may or may not fight you, or a bind could cause a split-second of slip-then-catch, is the best way I can think of to lose control.

And you're right; in a high-weight SUV losing control would more likely be a rollover than a spin.

Just to be completely clear, I don't think driving like how you are describing would result in any problems of any kind. But driving like I was describing could cause major breakage or injury if some idiot tried it in his brand new 4Runner after he reading on an internet forum that driving on dry pavement in 4H is perfectly normal and acceptable.

Can we at least agree to the fact that the maximum speed someone can safely take a curve in 2WD is faster than the maximum speed that same someone can safely take the same curve in 4WD? That if someone is stupid enough to try he will likely end up in the ditch?

 

[Dalko43]

In 4lo there is more torque applied to the drive line. It isn't uncommon to be spinning tires, or for a tire to be spinning in the air, then abruptly regain traction. You are also likely aired down and your tires have far more grip at 12psi than at 40.

On slick rock, you feel binding and tires bark loudly, often.

^^^ what he said. Those little noises you hear on drive pavement are nothing like the dynamic loads in rock crawling situations. Add in lockers/Atrack... and you have multiplied the traction potential and binding loads and yet it typically holds together just fine.

Again. smart drivers do everything possible to mitigate the loads, but sometimes there is no way to avoid it.

I have yet to see a TCase bust on a 120/150. CVs and rear thirds are common. The only reason the front diff does not blow all the time is that the CVs are so incredibly weak in comparison. The TCase is the least of your worries....

All the same, I would rather follow Toyota's advice on this subject then not follow it. The factory engineers obviously tested the crap out of the 4runner's 4wd and that's why they determined it was good for off-road use and not good for dry pavement use (in tight-turning situations that were previously described).

 

[Mikey01]

About a year ago, I recall a member that blew out his T-Case in the devils punch bowl. If I remember right the truck was less then a year old. I was looking for it, I think there was a lot more involved just kind of along the same lines?
It's a tool like a hammer, sometimes they brake, even if you take good care of them and do everything right. Chances are you will get more problems not using it then driving with it in 4H on fairly straight residential streets.

 

[blues]

Sorry fellas and gals for reopening a dormant thread but I've been reading my manuals to learn the systems on my new 2016 and, (though I think the referenced practice makes great sense), I can't find the paragraph in my owner's manual where it tells you to drive x miles per month in 4wd.

Could someone cite a page reference for my addled brain? (Or even a .jpg of the paragraph from a late model 4R.)

Thanks and apologies in advance. I'm trying diligently to read and absorb all the manuals that came with my vehicle.

 

[Bevo]

Here you go. Pg 234 in the 2015 manual, not sure what page it would be for the 2016.