Need help with transmission settings

[blacter]

I have an '08 4Runner with the V8 engine. I bought it in the summer and have just driven it all the time with the transmission in "D." Now that winter's here I'm trying to figure out the various special settings, but am not getting very far from the descriptions in the Owner's Manual.

Looks like in addition to the gearshift controls, I have a dashboard knob that switches from H4 to L4.

Also these switches:

• Center differential lock switch
• Auto LSD
• Downhill Assist Control (DAC)

Could I talk one of you into explaining when I'd use the various options. I don't drive off-road, so my only non-standard driving is on icy roads and towing.

 

[CJ3Flyr]

I have an '08 4Runner with the V8 engine. I bought it in the summer and have just driven it all the time with the transmission in "D." Now that winter's here I'm trying to figure out the various special settings, but am not getting very far from the descriptions in the Owner's Manual.

Looks like in addition to the gearshift controls, I have a dashboard knob that switches from H4 to L4.

Also these switches:

• Center differential lock switch
• Auto LSD
• Downhill Assist Control (DAC)

Could I talk one of you into explaining when I'd use the various options. I don't drive off-road, so my only non-standard driving is on icy roads and towing.

For non-offroading you need to do nothing. 4HI is probably best for all-weather conditions. There are some, low-speed, deep snow scenarios where the auto-LSD button or the center-diff lock could be very helpful. Other than a boat ramp or off-road 4LO won't help you much (based on your described usage).

If you are about to pull-out onto a busy road in the snow or in a deep snow bank the Auto-LSD switch is handy. It defeats part of the 'STAR safety net'; the power robbing aspect of the VSC. This could be very helpful especially if brisk acceleration is required (and you're ready for a little wheelslip). The downside is it will allow for aggressive wheelspin and slipping. It's also helpful getting up an unplowed driveway etc.

The center diff lock also defeats the power robbing component of the VSC. The center diff lock ensures that the front & rear axles get an even 50/50 of the power from the engine. It's very helpful off-road and very deep, low-speed stuff. The warning is two fold: 1) Don't use it on hard surfaces. The surface must allow for slip. Wet pavement isn't slippery enough. The t-case will bind as you go around turns because the F&R axles travel slightly different distances. A little wheelslip is necessary to prevent the binding hence the 'don't drive on hard surfaces' directive. 2) Do lock and unlock the center diff for a couple times monthly. Exercising the servo and lock is the best way to insure that it'll work when you want it to. Basically anytime you get a stretch of dirt road or soft gravel/dirt parking lot lock & unlock it.

To get it in 4LO place the vehicle in N and turn the switch; wait for a steady 4LO indication. Sometimes letting the vehicle roll a bit helps with the transition. I'd do this once a month too so that the servos get exercised and will be reliable over the long haul.

DAC- It only works in 4LO and is for off-roading. It helps you to maintain a very low speed downhill via the ABS brakes. It helps you retain steering control and a low speed going down very steep inclines in D through L or R.



:cheers:

 

[JB.]

[*]Auto LSD

I don't wish to cause any confusion as the reply by CJ3Flyr was very complete. I have a question, though.

The Auto LSD switch has a picture on it, right? Where did you get the term Auto LSD from? The manual?

 

[CJ3Flyr]

Re: Re: Need help with transmission settings

I don't wish to cause any confusion as the reply by CJ3Flyr was very complete. I have a question, though.

The Auto LSD switch has a picture on it, right? Where did you get the term Auto LSD from? The manual?

I am curious too, I thought the switch said VSC off. (I don't have an '08 though so I am only going on what I have read about '08's and a pretty good understanding of these systems.) Either way the function is the same* and I stand by my prescribed usage


* The switch basically allows the ATRAC or auto limited slip to work without the engine cutting back at the 1st sign of wheelspin.


:cheers:

 

[JB.]

Re: Re: Re: Need help with transmission settings

I am curious too, I thought the switch said VSC off. (I don't have an '08 though so I am only going on what I have read about '08's and a pretty good understanding of these systems.) Either way the function is the same* and I stand by my prescribed usage


* The switch basically allows the ATRAC or auto limited slip to work without the engine cutting back at the 1st sign of wheelspin.


:cheers:

Your descriptions and recommendations were right on. I'm just trying to understand the context of the Auto LSD term. For instance, whether Toyota has expanded the term to apply elsewhere than 2WD models.

 

[jimmy2x]

Chris - great info. I have an '08 V6. For locking the axles you say not on a paved road. Where we live dirt roads are few and far between. Any suggestions?

 

[CJ3Flyr]

Chris - great info. I have an '08 V6. For locking the axles you say not on a paved road. Where we live dirt roads are few and far between. Any suggestions?

For clarification: you're locking/unlocking the center differential not the axles. I guess you could say you're locking them together... You don't have to lock them for longer than it takes to complete the lock/unlock cycle. Truthfully, parking on a lawn is enough. Do it with the wheels straight makes it work easier without tearing the lawn up. Alternately if you have a place where you can get the steering wheel dead straight and do a quick lock and unlock cycle you'll be fine. The trick is don't turn or drive any distance. I am talking about rolling ahead 15ft to complete the lock and another 15ft forward or backwards to unlock it.

Make sure you run the 4wd mode for 10 or 20 miles every month to lube stuff up. The owners manual has the specific mileage/month recommendation.

When playing with the diff lock it must be stablized in 4HI or 4LO before you do it. By stabalized I mean no flashing lights on the dash, all 4wd indicator lights should be steady state. Good luck!


:cheers:

 

[jimmy2x]

OK Chris - I can do that in an abandoned parking lot - 15' forward and 15' back - straight and slow. Thanks.

 

[MikesToy]

I have an '08 4Runner with the V8 engine. Now that winter's here I'm trying to figure out the various special settings, but am not getting very far from the descriptions in the Owner's Manual.

I don't drive off-road, so my only non-standard driving is on icy roads and towing.

If you're worried about driving on icy roads (where the roads are half ice and half snow and it's like below 32 degrees), just put it on 3d gear and don't go over 40mph. If you slip, your VSC should engage and you'll hear a bell ringing. Don't panic and DON'T slam your brakes but gradually step on the brakes (ABS should do the rest) and steer out of danger, you'll come to a full-stop unless you have road clearance and want to start gassing up again (the 4WD will get and move up easily than any 2WD, but it will not stop on a dime for you).

 

[CJ3Flyr]

I have been thinking about something with regards to this. I gave some semi-wrong advice...:bash:

IMHO the V6 guys don't need to worry about exercising the diff lock. Each time you cycle from 2HI to 4HI it locks the center diff while in transition. So other than the physical switch the system gets periodic exercise when you go between 2 & 4HI.

V8 folks, I stand by my recommendation to excersise it periodically.


:cheers: