chiph9

Page 311 in the 2003 owner's manual (other years of the GX470 will be the same procedure)

http://drivers.lexus.com/t3Portal/do...5U/pdf/3-1.pdf

But basically, to change between Hi and Lo, stop the vehicle, put it into neutral, then move the transfer case lever. You might need to let the vehicle roll a bit to allow the gears to more easily mesh. You can drive on pavement on either Hi or Lo, but be aware that you'll have a lot more torque in Lo, and this could cause wheel slip. As well as really limiting your top speed.

The manual doesn't say you have to stop to engage the center differential, but it's probably a good idea. Make sure cruise control is off, then press the button. The dash light will blink and then stay on solid while it's engaged. If it keeps blinking, let the vehicle roll a bit. DO NOT drive on high-traction surfaces with the center diff locked. Do not drive for long distances with it engaged. VSC will be disabled when it's engaged.

DO NOT park or leave the vehicle with the transfer case in neutral. It will roll away unless you lift the parking brake handle. There's a dash light to remind you..

Use these 4WD system aids when you need additional traction.

Chip H.

ALAN553

You can lock the differential on the fly, no need to stop...maybe let off the gas for a sec, but you want to be able to do this when the road conditions change suddenly on you. Which is different from changing the transfer case from hi to low...must be stopped and in neutral.

LoneHiker

Lots of GX owners have never owned a true 4x4 before, and it causes no end of problems that they don't have any understanding of how they work. It's best to do some research and learn how true 4x4 works as opposed to full-time awd or the fake 4x4 that Honda uses. You will have a much better understanding of how and when to change modes.

I can give you some Cliffnotes, but it's not as helpful as actually learning what is going on underneath you:

1. You can press the 4x4 button AT ANY TIME to lock the transfer case in 4x4 mode. This takes it out of AWD and puts it into true 4x4. This mode should not be used on dry pavement, although it can be used for short periods without damage if someone accidentally engages it.

2. In order to move the transfer case shift lever from Hi to Low, you need to be stopped and the transmission needs to be in Neutral. This is normally only used for offroad driving. Typically you will place the transmission in gear 1 or 2 after Low is activated. It does not matter if the 4x4 button is engaged or not, but for offroad driving, you would want 4x4 engaged.

The GX isn't going to change modes over a certain speed like Honda does. Honda does that because it's a weak and terrible system designed as a marketing gimmick. It would destroy itself if you drove over 15mph with it engaged.

Htony

Stop and engage your choice. Low range speed is really crawling.
If you don't want to harm gears.
They are used when really stuck. If you can't get out of the situation,
next you'll need a winch.