gs350fan

There is a wire going to the TC. Wondering if one were to apply a certain voltage, it would lock a clutch and lock the front and rear axles. I know it is doing something like that if it slips, but on snowy ground it may be useful.
I believe we have a planetary center diff (which acts as an open) but there is a clutch that can lock things.

There is no pid in Techstream that shows clutch percentage (unless I'm not finding it). On my Explorer this can be set in a scan tool, or you can apply voltage to that wire.

potatomon

I believe mine stays locked most of the time because when I go to pull a U turn the car shakes and wheels skip and hop. Suspecting an overheating 4wd ECU since it's so close to the cat converter. 10 mins with engine off is all it needs to be good again...I am sick of it and just about ready to go get another transmission.

I miss my corolla..

gs350fan

Easy to diagnose, just pull the harness on that ECU.

potatomon

​​​​​​and it's going to stay off?

what is the point of locking the center diff? I kinda understand what is does - makes the front and rear axle spin at same speed but in which situations is it supposed to lock/unlock?? and what benefits does it provide? Doesn't it get locked electronically(hydraulically) when wheelspin is detected?

gs350fan

It does.
Any time delay when it is slippery is not good.
All trucks and real 4x4 are always locked. Subaru has this feature now.

Once you lock diffs your vehicle is a true 4x4. You must be offroad or on slippery surfaces. Otherwise you know first hand what happens

potatomon

damn shoulda went with a 2wd model why didn't I consider this... 2wd tranny is much cheaper. no vc center diff - more reliable.

4wd will run into drivetrain issues sooner.

gs350fan

Our trans is identical to a Toyota Tundra. There may be more or less clutches but it is a drop in.

potatomon

Wikipedia does not lie

A760E[edit]

6 Speed Automatic Transmission

Applications (calendar years):

• 2006 Lexus GS 300
• 2006 Lexus IS 350
• 2007 Lexus GS 350
• 2007 Lexus IS 350
• 2010 Toyota Tundra 4.6L
• 2010 Toyota Sequoia 4.6L

gs350fan

Yep the RWD is identical.
AWD has a different xfer case from the truck.

Probably somehow it could be swapped for real 4wd. I don't think the truck xfer case is computer controlled. Size may be an issue.

gs350fan

Yeah, there is definitely a signal being sent from an ECU. If you want to experiment hook up some voltage to that wire.
At your own risk, but what usually is there is an electromagnetic ball ramp clutch that can lock something.
That would be some mod for enthusiasts, maybe someone tried it already. I am going to search the forum.

ibidu1

iTrader: (1)

Many cars would have an open diff, or a limited slip diff. Lockers are mostly for trucks or all out race cars.

gs350fan

Many cars have a button to lock the center diffs. Subaru WRX is permanently locked I think.
I was playing with the car on a split slippery surface, left wheels on slick ice.

There is definitely a clunk when the center diff locks. Would be amazing on slick surfaces if it could stay locked. Then again, it may not be best for a soccer mom driving it.

potatomon

can't pull a u turn with a locked diff mayne

gs350fan

That is why the user has to know when to use it, and there isn't a button. When there is ice or offroad, it can benefit.

Not so much on dry pavement. Our planetary diff is very forgiving, you could even have different tire sizes, but it isn't as aggressive. Different tire sizes may start activating the clutch, I don't know. Some AWD cars require exact tires.

gs350fan

The Tundra that shares the transmission has a stick to shift into 4x4. There is no auto mode from what I understand. When the weather gets bad or go offroad, you move the lever. They know their audience though. They aren't selling the truck to yuppies or soccermoms.