Reliability of off-road features (DAC, HAC, AHC, KDSS)

[rstl99]

I am looking at a couple of used GX470's and am not familiar with the sophisticated suspension and ride components on these cars (my past SUV's were more "basic" i.e. 60 and 80 series LC's). Namely the:
Downhill Assist Control (DAC)
Hill-Start Assist Control (HAC)
Rear Adjustable Height Control (AHC)
Optional Kinetic Dynamic Suspension System (KDSS)

Although I don't plan on taking a GX470 on extreme off-roading expeditions, I do travel remote country roads and hilly terrain so would need to know I can rely on those components if-when I should need them.

1. how reliable are these in a 10+ year old GX470 with 120-150,000 miles on it?
2. how difficult or expensive to repair if something goes wrong?
3. how to check whether they are all working right, when looking over and test driving one?

Thanks.

 

[ultrakill]

In my opinion, DAC/HAC is so standard in so many vehicles now a days, those things are mostly controlled by ECU. Probably would never have issues with those.

AHC may require maintenance once or twice in life-time, but after first fail, most people would just swap in springs, and forget about it.

I don't have KDSS but from what I've heard there are no real issues other than installing sliders and other stuff onto frame.

 

[rstl99]

Thanks Ultra that's helpful. Yeah, it's been a while since I've shopped for a 4x4 and the GX is a lot more sophisticated vehicle than all the ones I've owned before (many of which had only leaf-springs in the back!).

When I test drove a GX470 last week the ride was comfortable but it felt a little "bouncy" in a soft wallowing kind of way. The similar year 4Runner SR5 I test drove right after was firmer, more conventional feeling as far as suspension goes. The V6 4R and V8 GX were far apart as far as smoothness of drivetrain, acceleration, noise, and obviously there is no comparison with regard to interior comfort and amenities (other than I preferred the full-sized cubbybox/arm rest between the front seats in the 4R).

I suppose that if I am able to take a GX to a Lexus shop for pre-purchase inspection, they could advise me on the condition of the various suspension and ride control features?

BTW, I own an 83 MB 300TD wagon with the self-leveling-suspension (SLS) in the back, which still works quite well. A hydraulic system using a couple of gas-filled shocks in the back. I would assume whatever system is in a GX470 would be equally reliable in the long run?

 

[ultrakill]

Pre-purchase inspection is definitely a good idea.

I know what you mean about the soft wallowing way the GX rides. It is 100x better ride than my '90 Mitsubishi Montero, so I really like it.

In my mind, the ride of GX would be hard to beat from any other offroad-worthy 4x4 (maybe LX would be better I don't know).

The build quality of Lexus/Toyota especially on the LandCruiser/Prado is probably one of the highest of any vehicle so I would not be concerned with 150K mile vehicles.

The one thing to keep in mind is waterpump/timing belt job I think is on 90K interval. I purchased my '05 GX a few months ago with 111K miles, and had all services done on the dot (including waterpump/timing belt). I was comforted in the fact that the first owners took such nice care of this car, that I didn't hesitate to pick it up.

If you are getting a 150K mile vehicle hopefully you can get records of maintenance done, otherwise you may opt to do waterpump/timing belt yourself which will set you back another $2K or so (not sure exactly how much the job is).

Steering and front end stuff is pretty easy and cheap if it needs to be done, and you should be able to tell when you turn the wheel if that stuff is solid or not.

 

[rstl99]

Thanks for the tips Ultra.
The one I looked at had 130K and zilch records (2 owners, not serviced at Lexus, only a couple of minor service items showed up in Carfax report for some reason). Don't know about timing belt and water pump, nor anything else really. Used car lot, they bought it at auction out of town. Truck looks great inside and out, has some rust underneath but nothing horrible given it's spent 10 years in the N-E. These trucks come up seldomly in my area, which is why I'm tempted on getting this one checked at local dealer and see if I can swing a deal. Hard to anticipate imminent future repairs given lack of history and the age of it, always a bit of a gamble... Though as you say, much harder to go wrong on a Lexus than almost any other brand today...
Sounds like you got a good one, happy for you.

 

[co4wheel]

Plan on new shocks. All oils. Basic stuff to get you familiar and knowinging it's fine.