4WD, Lock Button, VSC Off Button and DAC Button - How They Work - Page 3 - Toyota RAV4 Forums
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post #21 of 29 (permalink) Old 02-19-2014, 12:17 PM
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DVS is correct on post #15. The front differential has no mechanism for locking itself and thus sending equal speed to each wheel. From the ABS sensors it does know each wheel's speed. Auto LSD brakes the wheel that's spinning faster.

Traction control on 4WD does the same thing on the rear wheels also. So it has Auto-LSD on both ends. During my getting-stuck tests I've heard the heavy almost disconcerting thumping noises the ABS makes on whatever wheels are spinning. Then if the Skid Control ECU doesn't see the vehicle moving it essentially gives up and takes the throttle away from the driver. Turning TRAC off allows the driver to spin the wheels w/o traction until he either gets unstuck or breaks something.

What I don't know is does Auto-LSD also have the ability to reduce throttle when it sees no movement? And does turning it off allow spinning the tire with the least traction? I do know that when I got my FWD Accord "stuck" with both front tires on ice, both were slowly spinning with my foot to the floor. So it must have some sort of auto-LSD but I never heard any thumping.
I thought the trac button was same as LSD button. But doesn't the 2wd also have a trac button?
Dr J
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post #22 of 29 (permalink) Old 02-19-2014, 12:22 PM
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I don't even bother watching staged promotional videos, especially unrealistic situation ones.
They're like when someone with a Harley claims he has some high HP number. I say, "Okay let's see it on MY dyno." I've seen it be true once in 15 years. (I tested that bike for the editor of American Iron Magazine. He was doing an article but didn't believe the builder's dyno numbers. He confirmed it on my and a third dyno. All three agreed within measurement error.)
I was planning on going with a 2008 forester turbo manual. But ended up going with rav4. During my subaru research, it turns out they do not have front LSD. Yes they can send up to 50% power to the front wheel but it's an open diff. Sounds ok for the average city commute, but won't work in tough stuff, I noticed in those videos they always have 1 rear wheel with traction. I don't know about current Subaru.

That being said, I can't wait to take delivery of my 4.3 and find a willing suby owner who wants to try and get stuck with me!
Dr J
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post #23 of 29 (permalink) Old 02-19-2014, 01:25 PM
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I thought the trac button was same as LSD button. But doesn't the 2wd also have a trac button?
Dr J
We don't have any 2WDs around here but I know one guy in Texas who has two.
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post #24 of 29 (permalink) Old 02-19-2014, 01:37 PM
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I was planning on going with a 2008 forester turbo manual. But ended up going with rav4. During my subaru research, it turns out they do not have front LSD. Yes they can send up to 50% power to the front wheel but it's an open diff. Sounds ok for the average city commute, but won't work in tough stuff, I noticed in those videos they always have 1 rear wheel with traction. I don't know about current Subaru.

Dr J
Yeah, it was a big letdown to watch one front and one rear wheel spinning when I got my mom's supposedly invincible symmetrical AWD 2007 Legacy hung up on a snow drift in PA a couple of years ago. According to the sales flyer I looked at later we'd apparently bought the non-invincible model.
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post #25 of 29 (permalink) Old 02-20-2014, 02:07 AM
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For the sake of conversation, let's discuss the opposite of all this traction stuff. I'm a grip driver. I like Willow Springs and Streets of Willow. Let's say I want a track day with my 4WD. What settings to use? The only 1 I can think of is launching with 4WD LOCK. All the other nannies should be turned off?

Can/will the 4.3 pitch into a corner with inside wheel lifting, doing a 3-wheel dance around turns?

Dr J
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post #26 of 29 (permalink) Old 02-20-2014, 11:00 AM
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Can/will the 4.3 pitch into a corner with inside wheel lifting, doing a 3-wheel dance around turns?
Dr J
Yeah probably could.

Then 2 wheels.

Then 0 wheels.
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post #27 of 29 (permalink) Old 02-20-2014, 03:06 PM
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Buy a car if you want to track? The Rav isn't really agile...at all. (my other car is a mazdaspeed 3)
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post #28 of 29 (permalink) Old 01-25-2016, 12:27 AM
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The section on: What to do if stuck in snow or mud, or to help prevent getting stuck

should remain relevant even for the Hybrid AWD, correct? I've read a few posts on other threads that when stuck, the rear wheels might not even start spinning because it can damaged the hybrid motor. Because of this, I'm not sure if the same process is to be followed. I'll have a look at the owner's manual again this week to confirm what the driver is suppose to do.

It's winter so I'd like to know so that I can relay the instructions to my dear wife.

Edit:

There is definitely no 4WD Lock Button on our RAV4 Hybrid and the owner's manual instructs the driver to turn TRAC off, to rock the car back and forth and don't over spin as it can damage the hybrid motor.
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post #29 of 29 (permalink) Old 01-25-2016, 07:23 AM Thread Starter
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I wrote the original post nearly 2 years before the hybrid version became available.

The concept should be pretty much the same, without the lock button, because the AWD system is completely different on the hybrid (essentially uncontrollable).

All you can do is turn off the nannies and try rocking it back and forth, taking whatever the system will give you. This is also true if you were in just a FWD vehicle.

I would much prefer trying to get unstuck in any non-hybrid AWD RAV4 over the hybrid version any day. The inability to force power to the rear wheels is a significant hindrance, if you ask me.

If you live where there's lots of snow or mud or go out on the beach or something like that and AWD is a very significant concern/priority, I'd pick any other or previous RAV4 with 4WD first.

If The Almighty MPG is your top priority over system performance in those conditions, then the hybrid (and maybe an automobile club membership) is probably the better choice.

.

Silver 2012 RAV4 Limited V6 4WD with Tow Prep (3500 lbs towing capacity!), OEM Hitch, Remote Start and Dashcam.

Long live the RAV4 V6!
Best. Vehicle. Ever.
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