Or is the GX an all wheel drive car? Can you actually disengage the front axle?

Thanks

 

It's a bit of a mix.

it has a torsen center diff, which gives it full-time torque-sensing AWD. Good stuff. Just like the 4runner and the Audi a4/a6/a8/q7 among others. this gives it great year-round traction in rain/snow/dirt/etc.

Beyond that, though, it has:
- 2-spd transfer case to give it low range
- ability to lock the center diff for "true" 4x4
- hill descent control
- rear limited slip diff (IIRC)

 

The GX is full time 4wd.

 

I'm fairly certain that GX does not have a rear limited slip diff. It does have ATRAC which uses the antilock brake system to control wheel spin at each corner. I suppose you could say that ATRAC functions like a quasi limited slip diff, but it really isn't a true limited slip diff.

As to the original posters question of whether or not the GX is a "true 4x4" the answer is yes. In fact it won several 4x4 awards when it first came out - see links in my sig. No, you cannot disengage the front axle - it's always in 4x4 (same as V8 powered 4Runners). The V6 powered 4Runner does give you the option of disengaging the front axle, but not the V8 powered ones.

 

Yes, the GX is a true 4x4. I think the main difference(s) between AWD and 4WD is a 4WD has a high/low gear transfer case while a AWD doesn't. 4WD can be the old-fashioned part-time 4WD with or without locking front hubs (you have to go outside the vehicle, lock the front hubs, then shift t-case into 4WD...a PITA, but saves 2mpg and is more robust offroad) where you have to shift from 2WD to 4WD. In the LX/GX/LC, you have full-time (permanent) 4WD, so you just have to choose between low and high gear while in the 4Runner V6, you have to engage 4WD, then choose high or low. 4x4's usually have more ground clearance, as they are intended for offroad driving while AWD is more for slippery pavement.

When do you really need low? When you are driving up a long, steep (usually offroad) road. Say you are going 10mph uphill. In a AWD or 4WD high mode, you'd be in 1st gear while in 4WD low, you'd be in 3rd-4th gear. So what? In 1st gear, the torque converter in the transmission is constantly slipping, generating heat, so the ATF gets hotter the longer you climb. If it gets too hot, the transmission will overheat. OTOH, when the tranny is in 4th gear, the torque converter is locked up, so there's no slippage and lost energy. This means not only is it better for your tranny and tranny fluid, but you also lose less energy as heat and more to propel you forward.

My 2 cents.

 

The GX470 is technically not a true 4x4. The Toyota Land Cruiser 70 Series with locking front/centre/rear differentials is a true 4x4. But I guess if power is directed at all four wheel it could be called a 4x4.

 

It is also very helpful when you're going down a steep hill....

 

Others in USA (still in production): Jeep Wrangler Rubicon, Dodge Power Wagon, Mercedes G-wagen, Hummer H3T.

 

The 4runner and FJ are almost there with locking centre and new for 09 locking rear on the v6 4runner.

 

Yup, the rear locker + A-TRAC ('09 4runner TE & FJ) is a very nice combo.

One small addition to my list above...although extremely rare, i think that a few VW Touareg did come with lockers front and rear...i think. Of course, whether these lockers work or not is another question.

 

What I can't believe is that Toyota's flagship Land Cruiser does not have a least a mechanical rear locking differential.

 

Well, this kinda points to the fact that Toyota no longer views the TLC/LX as it's major off-road vehicle. That title has now fallen on the FJ (and '09 4runner Trail Edition) shoulders. The TLC/LX is now more of a luxury cruiser with off-road capability, not the other way around. "Crawl Control" is kinda the A-TRAC version of the FJ and allows for idiot-proof control, but it is no substitute for lockers.

I can't blame Toyota for doing this because most people who do take their vehicle off-road do not want to spend $70,000+ on their vehicle. These off-roaders prefer the cheap base models, e.g. 4runner SR5 with Trail Edition package for example. The FJ is along the same idea...basic 4x4 vehicle costing around $30,000. Hell, if the FJ, 4runner Trail Edition, or current Jeep Wrangler Rubicon were available in 2004, then i would probably be driving one of those vehicles now. Don't get me wrong, the G500 is extremely capable (only slightly below Rubicon in off-road capability), but it is also extremely painfully expensive to fix off-road damage (a small plastic bumper cap runs $200 each!!).

 

Well, yes and no. The Landcruiser sold here had the rear diff lock option through 1999. It has always been offered overseas, even in Japan where they have nowhere to go 4-wheelin'. I guess American consumers had no idea what the switch did and when/why to use it? I've heard that the Middle East LX470's come with factory rear and front diff locks. Overseas cruisers also had the AHC the whole time (Just like the LX470 here did), yet it was only "introduced" on the 2006 model here.

 

Toyota stopped the rear diff lock because ATRAC was used instead, which provides more idiot-proof function. The rear locker option was clearly used for off-road only, while ATRAC was more "practical" to the average consumer (all-season, all-weather traction). So, Toyota put in ATRAC technology that average consumer who bought the TLC100 actually needed. (Note: ATRAC in the TLC/LX is not the same as A-TRAC in the FJ Cruiser and the upcoming '09 4runner Trail Edition.)

This also explains why only 10% or so of TLC80/LX450 that came to the US had the full set of front and rear lockers. Most do not.

As for overseas TLCs with full lockers in the present day, i think that the ONLY TLC that has these lockers are the TLC105. The TLC105 is basically a TLC80 (solid axles front and rear with lockers) with TLC100 bodyshell on top of it. So, i do NOT think that there is any TLC or LX in the world with full set of lockers and a front independent suspension (IFS). Toyota clearly stated this with the introduction of the TLC100 that the front locker went into the trash can with the introduction of the IFS.

AHC is a cool thing to have and is beneficial in off-roading to some extent. However, the electronic gizmos and the maintenance of that system makes it undesirable when you're in the middle of nowhere. Again, this was mentioned by Toyota as to the reason why the TLC200 does not have AHC. Toyota apparently regards this feature as more of a luxury item than a true off-road tool. Personally, i like AHC because it increases your angles (approach/breakover/departure) off-road.