Good morning everyone

Recently picked up a 2016 GX460 Base with Nav and Blind Spot Detection for my wife.

Wife was asking when/where would it be proper to use the center diff lock and/or 4 Lo on transfer case.


I mentioned that both were meant to get "unstuck" from sticky situations and are not meant to be used at highway speed. Years ago I owned a 2000 Wrangler Sport and thats when I used my 4 Lo setting at least.

Am I correct in my description? I was minding our 16 month old while she was getting the walk through from the salesman and wasnt present when he was describing these systems.

Many thanks and I look forward to being a member of your community.

 

I'll use 4Lo to pull a boat up a ramp, low speeds off road, climbing up an icy driveway.

Locking the center diff will allow tire spin/disable traction control.

I've run 4Hi locked when the roads are very bad with snow.

Try to anticipate if you need 4Lo or a locked diff. If you wait until you're stuck, you've lost half the battle. I don't park in a garage. If a lot of snow if forecast, I'll park locked in 4Lo.


P. 336 of the owners manual:

H4 (high speed position)

Normal driving on all types of roads.

L4 (low speed position)

Driving requiring maximum power and traction such as climbing or descending steep hills, off-road driving, and hard pulling in sand or mud, etc. The low speed four-wheel drive indicator will come on.

Center differential lock/unlock switch

Lock the center differential when your vehicle’s wheels get stuck in a ditch or when driving on a slippery or bumpy surface. Unlock the center differential after the wheels have been freed, or after moving to a flat, non-slippery surface.

 

The CDL locks in the front/rear power distribution at 50/50, so that 50% of the power goes to the front diff, and 50% to the rear diff. It's OK to run it at higher speeds for short distances (i.e., snowy, icy roads) but I wouldn't drive that way for hours and hours.

I doubt your wife would ever need 4Lo, but it's definitely useful in slow speed situations where you need a lot of torque like getting unstuck or climbing a steep, slippery hill.

 

1. Even with CDL locked both front and rear differentials remain unlocked. It means it's safe to drive with a locked CDL anywhere you want for however long you want. The only difference is instead of 40/60 power split you will be getting constant 50/50 which might alter the way vehicle drives somewhat.

2. Locking the CDL should only be necessary if you anticipate one of the axles to have no traction at all. CDL in the GX is torsen which means it can vary power distribution between front and rear axles depending on the amount of traction available but it can not compensate for the situation where one of the axles have no traction at all (read up how torsen works). Locking the CDL will make sure half the power goes to each axle.

3. 4LO just gives you more power at the wheels at much lower engine RPM. Think about it as having gears way below 1st. Useful for pulling somebody out of the ditch, for example ;-)

 

No, that's not true.

Yes, the front and rear diffs are open, but the problem is that when you go around a corner, the front driveshaft wants to turn at a faster speed than the rear driveshaft. That is fine on slippery surfaces (like a dirt road or the beach) because the tires simply slip. But not OK on dry pavement.

Try it in a parking lot. Lock the center diff and try to turn. You'll see it is hard to do so. That is because the tires are scrubbing.

You don't want to do this much because it will bind up the drivetrain. In the 2016 manual, on page 337, it says:

And on page 339:

The manual is available online as a PDF here: http://drivers.lexus.com/t3Portal/do...f/OM60M73U.pdf

Locking the center diff on dry pavement is fine as long as you don't turn much.

 

Totally agreed. Only lock the center when you sense you might be stuck and unlock it (turn off) right after.