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Toyota 4WD systems explained

2487 messages,  Last post on Apr 28, 2012 at 12:48 PM

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What is this discussion about? Toyota Sequoia, Toyota Highlander, Toyota 4Runner, Toyota Land Cruiser, Toyota RAV4, Toyota Tacoma, Truck, SUV

Messages Page 247 of 249

#2458 of 2487 Re: Toyota 4WD in recently models [vavavavolvo] by misaak

Jan 07, 2011 (2:19 pm)

Replying to: vavavavolvo (Jan 07, 2011 2:04 pm)
Where do you buy the tires for $430 for Blizzaks?

#2459 of 2487 Re: Toyota 4WD in recently models [wwest] by daniell

Jan 07, 2011 (2:46 pm)

Replying to: wwest (Dec 27, 2010 12:33 pm)
1) You can get cheaper winter beater wheels.
2) You can get -1 or -2 size wheels. With those, you will need tires with taller sidewall which give better traction in snow and slush. Those are cheaper too, and the difference is significant for most brands.
3) I am not sure how much it costs to swap tires, say $50-$80. That's $100-$160 per year. Over a few years it adds up. If you keep your vehicle for a long time, it's proably cheaper to get the second set of wheels. Swapping wheels is something I can do myself in my garage, it takes me about 40-50 min., probably less than driving to a tire place (with 4 dirty tires in the trunk), and have them balance and swap the tires.
4) All that repeated swapping can't be good for tires.
Etc.

#2460 of 2487 Re: Toyota 4WD in recently models [wwest] by oldad1

Feb 10, 2011 (12:22 pm)

Replying to: wwest (Dec 27, 2010 11:17 am)
"F/awd system could be easily modified"
 
My 09 HL one wheel drive is nearly useless in the snow and I am wondering how one would go about modifying it as you described using a switch to over-ride the the clutch.
 
In your opinion would this help substantially or is it just wishful thinking?
 
I am pretty handy with a tool and would seriously entertain this idea, realizing of course (hoping really) that it would be like locking in a tranfer case.

#2461 of 2487 Re: Toyota 4WD in recently models [oldad1] by wwest

Feb 11, 2011 (11:15 am)

Replying to: oldad1 (Feb 10, 2011 12:22 pm)
Sorry, but I was referring to the NEW F/awd system now used in the Sienna, Venza, and RX350. Those have an electromagnetic clutch just forward of the rear diff'l that is used to dynamically apportion engine torque to the rear drive.
 
In those a simple switch might be used to fully engage the rear clutch provided that there is absolute certainty of a non-tractive, slippery surface.
 
Basically a "part-time" 4WD system.

#2462 of 2487 Re: Sequoia, Land Cruiser and 4Runner [cliffy1] by donovancook

Jun 24, 2011 (9:30 pm)

Replying to: cliffy1 (May 16, 2001 3:59 pm)
2003 Toyota Sequoia 4X4
 
Is there a way to override the TRACS and VSC system? I was heading up a muddy slope and it felt like the rev limiter kicked in and I couldn’t power up the rest of the way – it felt like it was trying to get traction and slowing the revs of the motor to do so.
 
Am I able to flash my ECU, pull a fuse, or snip a wire? Did I just buy a soccer mom taxi?
 
Thank you in advance for any insight or explanation anyone can extend.
 

#2463 of 2487 Re: Sequoia, Land Cruiser and 4Runner [donovancook] by wwest

Jun 25, 2011 (9:49 am)

Replying to: donovancook (Jun 24, 2011 9:30 pm)
In a true 4X4 if you lock the center "diff'l" that automatically disables TC and VSC. Sounds like in the conditions you had you needed to be in "locked" 4X4 mode.

#2464 of 2487 2011 Sequoia 4wd by 2000lc

Sep 23, 2011 (1:29 pm)

I am looking for a simple explanation describing the applicable conditions (when to use each and why) for using the (1) Auto LSD System; and (2) (when and why) to disable VCS or A-Track. This will sound dumb, but the Owner's Manual I think needs some interpretation to become clearer...Trac Off mode, Auto LSD mode, VSC off mode. Am I supposed to advance from Auto LSD to VSC OFF mode when I am trying to get unstuck, which I seem to be reading is a 2 -step process? Am I close to understanding this?

#2465 of 2487 Re: 2011 Sequoia 4wd [2000lc] by wwest

Sep 24, 2011 (9:47 am)

Replying to: 2000lc (Sep 23, 2011 1:29 pm)
The base problem arises from the fact that selective frictional braking is used to implement Trac, LSD, and VSC. If a condition requiring consistent, continuing, selective braking were to occur and the engine not be automatically dethrottled you would end up with warped brake rotors soon thereafter, or possibly engine failure of the drive train due to the extreme stress involved.
 
Since the driver cannot be trusted to lift the gas pedal to the point of "feathering" when one of these modes activates the system does it automatically for you.
 
So the only method for getting unthrottled wheelspin as a last resort to get unstuck, etc, is to disable ALL of these functions.

#2466 of 2487 4wd won't engage on 2005 sequoia by hankerkid

Nov 14, 2011 (7:43 pm)

Ok, so I guess I forgot to turn my 4wd on once a month on my 2005 toyota sequoia. From what I read online it is in the owners manual. Would have been nice for the dealer to tell me that when I bought it. Now when I hit the button it just blinks on the dash and never locks in or changes. The dealer wants to charge 92.00 just to look at it. I read on this forumn about a fix for my back window (got the defrost and wiper working which is all I wanted, so thanks to all for that). Any idea on my new issue? Hoping there is a way to reset it or get it to engage without a dealer charge. I wasn't able to find anything online other than one guy who took it all apart and replaced a bunch of stuff. I am not mechanical but also not an idiot so I could do minor things.
 
Please help as winter is here in Wisconsin.

#2467 of 2487 Re: 4wd won't engage on 2005 sequoia [hankerkid] by wwest

Nov 16, 2011 (8:08 am)

Replying to: hankerkid (Nov 14, 2011 7:43 pm)
It's sometimes easier for the 4WD clutch to "slip" into engagement accelerating, EASY acceleration, from a full stop, at a low speed, stopped, or even driving slowly, DEAD slow, in reverse.
 
It's even worse if you have new tires at one end vs the other.

Messages Page 247 of 249

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