LX570 AHC “Basics” - Added as sticky thread for AHC Issues (11 Viewers)

[beer]

Even if you removed there isn’t much to inspect. I did my globes at ~115k. It’s probably something you should consider soon.

Thanks. Seems I'll be doing them relatively soon if not now, so might as well be now. Just bought via JDMPlanet and am hoping for luck with quick shipping.

 

[teejnut]

Even if you removed there isn’t much to inspect. I did my globes at ~115k. It’s probably something you should consider soon.

What kind of specific improvements did you notice after the new globes?

 

[tbisaacs]

What kind of specific improvements did you notice after the new globes?

dramatic improvement in dampening

 

[32cls6speedmt]

Thanks. Seems I'll be doing them relatively soon if not now, so might as well be now. Just bought via JDMPartsNow and am hoping for luck with quick shipping.

do you have a link for jdmpartsnow?

 

[beer]

do you have a link for jdmpartsnow?

Post above edited to correct seller to JDMPlanet

 

[32cls6speedmt]

thanks, no wonder i couldn't find it. it is jdmplanet and not jdm parts now

 

[beer]

Flushed 7L through this weekend, went fine with no issues thanks to the excellent documentation over the years on this forum. Very thankful for that. Despite the old fluid visually looking fine and pink in the reservoir (see pg 18), it came out looking like a barrel aged stout. Definitely rides better, but I think there's still a little room for improvement, so I'm looking forward to replacing the accumulators when they show up.

 

[BigLexusMN]

Wow, 7 liters! That was definitely a stout. Nice work on this

 

[kyle94109]

Point of this thread is to serve as a repository for 200-series AHC info, including LX570 and LC equipped with AHC (in select global markets).

Let’s begin with a theory. The 200-series LC (without AHC) and the LX570 (or LC with AHC) are like New York & LA. LC “purists” are like New Yorkers, going on and on about the virtues of “tried and true” spring setups, but in order to enjoy their springs, they seem to have a need to talk some smack about LA/LX with its “over-the-top” hydraulic suspension, “unnecessarily complex” design, and high “cost of repair.” New Yorkers, in other words, make a hobby out of kicking LA in the shins.

LA folks, on the other hand, try to emphasize how similar LA is to New York — how similar the capability of the LX570 is to the capability of the non-AHC “cruiser” — we all know this anxiety LX folks have when they pull up next to a Land Cruiser. “One is a proper ‘off-road tank;’ the other is a ‘mall cruiser.’” But once LA/LX folks get over their anxiety, you don’t really hear a lot of “New York” bashing. There are differences and similarities, but LX folks are like Angelenos, they seem to be out enjoying their AHC-levitating rigs. After a ten-year model run, there don’t seem to be the catastrophic tales of woe we all imagined were “just around the corner”.

With a decade under its belt, it may be time to admit that the LX570 AHC system is just brilliantly engineered and built, working well across a dizzying range of climates, terrains, and rig stresses.

Below are some links to tech basics (including excellent schematics and repair guides). There is far too much new terminology and technical jargon to try to do anything like a “glossary” on AHC parts, and there’s been some confusion even about what to call the shocks/struts on the LX, given that they are hydraulic and come with so-called “actuators” — so rather than do that, what I learned is that it’s just easier to start familiarizing yourself with the diagrams and peeking under the running boards, to get a sense of how this part of the machine is supposed to work:

REAR SUSPENSION REAR SUSPENSION: REAR SHOCK ABSORBER: INSTALLATION (2008 LX570) (courtesy of another thread on this forum, can’t remember which)

There are a few links I’ll need to look around for, and will post as comments to this thread. There’s a 40-page .pdf floating around somewhere that attempts to explain the inner workings of the AHC, and it’s dense stuff. Some of the most candid assessments by mudders are those that are from folks with engineering backgrounds and so on, who write that’s basically, this stuff is “over our heads.” A lot of that probably has to do with the electrical engineering / coding that runs the whole system, specifically auto-leveling programs, load-balancing programs, traction-control programs, etc. It’s complex machinery, like a top-of-the-line Seiko watch.

Like that Seiko watch, what we all expect from the AHC is smooth & consistent operation. That only comes with time and trust in a particular rig after progressively rougher exploitation. In a separate comment, I’ll share some of the things I did in order to build up trust in the suspension components, and it’d be valuable to hear advice from mudders who bought into the 200-series AHC trip, especially when buying used —

1. How would you recommend prospective buyers test the system during their pre-purchase inspections?
2. What are good post-purchase “preventative maintenance” suggestions for folks who are new to 200-series AHC?
3. What are absolute “No-No” suggestions, in other words, mistakes you might have made that you want others to avoid making.
4. Etc.

Below is a schematic that shows fluid leak weak spots or “junction spots” — whatever you want to call it, but areas that Toyota mechanics identified on a schematic, so probably a good starting point for visual inspection purposes.

If the AHC-equipped rig you’re looking to buy is leaking suspension fluid from these spots, chances are, you’ll be learning a LOT about hydraulic suspensions in the coming months/years. For most folks, this will mean “run!” For others, it can signal opportunity.

View attachment 1677630

Such a great post.

I’m a new LX570 owner and had my 95k service. Received pictures of all four shocks leaking and a recommended replacement of all four and the front struts/top bolts.

Thankfully members of ih8mud and my Lexus dealership confirmed that the 1-2 inch leak is normal, and do not replace.

Before I got all that feedback I was worried alright that my expensive car purchase was about to really hurt.

Eagerly learning more about this system!

 

[Piyos]

Been lurking for a while on this thread and forum. Brand new to the LX platform and am coming from a 2004 4Runner. Just purchased my 2008 LX 570 (71,500 miles) and attempted the "AHC Sensor lift" Seemed pretty straight forward (followed the instructions posted by tbisaacs) except my underbody was coated with some sort of spray on liner. I was able to free the bolts and adjust the sensor, but the rake is exactly the same. Any help or trouble shooting would be greatly appreciated. Thanks,

Front measurement

Driver side sensor

From Ground to wheel well measurment

 

[grinchy]

Go drive it around and remeasure again.

 

[Piyos]

Go drive it around and remeasure again.

Thanks for the response. I drove it about 70 miles after adjusting the sensors with multiple adjustments to the HT settings (H,N,L) and stops in between. Even right after adjusting the sensors I cycled through all the settings. There are several bolts that make up the sensor connection. I’m not sure the other bolts are able swivel due to the aftermarket undercoating. Should I loosen the other bolts and then re-tighten? I’ve read that the height adjustment can vary from time to time due to the computer recalibrating but so far no luck removing the rake. Still pegged at 35” from ground to wheel well.

 

[lx200inAR]

Thanks for the response. I drove it about 70 miles after adjusting the sensors with multiple adjustments to the HT settings (H,N,L) and stops in between. Even right after adjusting the sensors I cycled through all the settings. There are several bolts that make up the sensor connection. I’m not sure the other bolts are able swivel due to the aftermarket undercoating. Should I loosen the other bolts and then re-tighten? I’ve read that the height adjustment can vary from time to time due to the computer recalibrating but so far no luck removing the rake. Still pegged at 35” from ground to wheel well.

35” seems high. It looks like you adjusted front and back, if you wanted rake to change you should have only moved front.

 

[Piyos]

35” seems high. It looks like you adjusted front and back, if you wanted rake to change you should have only moved front.

Didn't touch the back sensors (only the fronts). 35" was the measurement before and after.

 

[AnyMal]

For visibility please see my complete AHC diagnostics write up here.

 

[Bunga]

Thanks for the response. I drove it about 70 miles after adjusting the sensors with multiple adjustments to the HT settings (H,N,L) and stops in between. Even right after adjusting the sensors I cycled through all the settings. There are several bolts that make up the sensor connection. I’m not sure the other bolts are able swivel due to the aftermarket undercoating. Should I loosen the other bolts and then re-tighten? I’ve read that the height adjustment can vary from time to time due to the computer recalibrating but so far no luck removing the rake. Still pegged at 35” from ground to wheel well.

I think you ID'd it. Those joints all need to move. I can't visualize why the extension didn't change a little at least, but in any case: scrape them down and wiggle them laterally. They need to be free.

 

[Piyos]

I think you ID'd it. Those joints all need to move. I can't visualize why the extension didn't change a little at least, but in any case: scrape them down and wiggle them laterally. They need to be free.

Thanks for confirming my suspicions. Just need to figure out how to clean them properly.

 

[grinchy]

Ravenol AHC fluid: Ravenol Item 1324101 <no US source located, about EU20 + shipping/liter>

Nissan AHC fluid: KLG01-00502 <no US source located, about $400 for a 20L (5 gal) can on Ebay>

 

[Omsok]

Thank you for clarification.

Fun fact. -40°C = -40°F
I experienced this firsthand while living in Yellowknife.

 

[Omsok]

Have these been verified as acceptable?

Ravenol and Nissan oil?