AHC History and possibilities (1 Viewer)

[tincan45]

I have been doing lots of AHC research recently. Mostly because I couldn't find an acceptable LC I could afford and ended up purchasing a LX. AHC seemed like voodoo to me a few weeks ago. As result, I wanted to educate myself in the event I find myself needing to service the system. Talking to dealers and other Toyota guys was not reassuring as they also glossed over when AHC questions arose.

I'm starting to realize how amazing this system really is. With over 70 years of innovation and engineering, I understand why Toyota decided to adopt and license* the technology. While it's been around a long time, I don't feel like it's off-road potential hasn't been fully tapped.

Here are a couple "What if?" thoughts for discussion:

1) What if AHC could auto level your rig when you stop to camp? RTT owners rejoice!
2) What if AHC could be used to change a tire w/o a jack?
3) What if AHC could allow you to make it home on 3 wheels?

Understanding the tech leads me to believe all of these are possible.

The most educational video I could find was actually a tribute to the Citroen. If you have a few minutes, I think you will have some of the same thoughts I mentioned above. You will also be able to make the clear connection to AHC as we see it today.



REF: Hydropneumatic Suspension Wiki

UPDATE: Here is a short Mercades SLS repair video that goes into globe maintenance and the importance of globe change intervals.



Note: The wiki has some interesting details regarding the fluids used. In short, AHC fluid is mineral oil, but it's Achilles heel is dust inhalation. This provides good support for the change intervals, and might require more frequent changes in extremely dusty environments (i.e Off-Road).

*This is an assumption based on the fact that users here on the forum have used the Citroen globes in place of the toyata globes. @TeCKis300 seems to have a much better knowledge of the system. Perhaps he can chime in. Here he mentions Toyota licensing the tech when discussing the Jacking topic above.

 

[UCrazyKid]

Please share your other resources on AHC. I would love to know more about it. I didn’t realize it was a licensed tech or that it was so old! I love the AHC in my 2011 LX. More more on AHC in this video:

 

[CJ3Flyer]

Cool footage in that vid and yes to the similarities.

1) As for leveling when parked that would be easy if Toyota chose to offer it.
2) That’d be great to change a tire or lift a wheel with no jack but the Boy Scout in me would want to be able to traditionally jack it as well. Offroad this might be awesome to get a track under a wheel if stuck.
3) Modern risk mitigation (lawyers) ain’t gonna let that happen...

I went down the same path as you in the sense that learning about the AHC just increases the appreciation of it’s function/brilliance.

 

[tincan45]

Please share your other resources on AHC. I would love to know more about it. I didn’t realize it was a licensed tech or that it was so old! I love the AHC in my 2011 LX. More more on AHC in this video:

I updated the original post with some References and added links.

 

[Sac Cerevisiae]

Some additional videos discussing hydro-pneumatic (and like) suspension systems.

Rivian discussing it's hydro-pneumatic suspension


Citroën C6

 

[TeCKis300]

McLaren's MP4-12C’s also uses a flavor of Tenneco's Kinetic Suspension.

WRC and Dakar race teams used the system, only to be banned as an unfair advantage in 2006.

The system fitted in the LX 570 is more broadly capable and complex than any of those flavors.

I'll post more when I'm home later.

 

[tincan45]

Well I go curious...AHC tire change works!

Not as well as I had hoped, but it works. I'll make a video soon.

 

[tincan45]

Some additional videos discussing hydro-pneumatic (and like) suspension systems.

Rivian discussing it's hydro-pneumatic suspension


Citroën C6

Interesting how all of these work EXACLY the same. Almost identical measurements between L/N/H across the board. I bet it's the same ASIC chip that was developed 20 years ago and just keeps being updated and reused.

 

[waybigdog]

The Slee site says that AHC was an option for 2006 LC's.
I have not been able to find any info on AHC being on 200's?
Anyone have a link or any info ?

Thank you

 

[CJ3Flyer]

The Slee site says that AHC was an option for 2006 LC's.
I have not been able to find any info on AHC being on 200's?
Anyone have a link or any info ?

Thank you

I know various markets in Europe have it. Someone from Italy has posted about an LC200 with AHC here. I might check S.A. and Australia too. Those would be English language websites which helps (us).

 

[bloc]

The Slee site says that AHC was an option for 2006 LC's.
I have not been able to find any info on AHC being on 200's?
Anyone have a link or any info ?

Thank you

AHC came on all LX570s in the states.

 

[TeCKis300]

The Slee site says that AHC was an option for 2006 LC's.
I have not been able to find any info on AHC being on 200's?
Anyone have a link or any info ?

Thank you

The 2006 and 2007 LC's were 100-series. These two final years of the 100-series LC's had an AHC option. I'm not aware of any 200-series LC's getting this option. Some other markets did see some LC's get and AHC option.

There's a thread here with much more AHC info - LX570 technical Wiki?

 

[grinchy]

Comparing LX570 to LX470 AHC

 

[grinchy]

overview

 

[grinchy]

And here is why we only ever replace the low pressure accumulators. Because the other two types use metallic bellows and effectively don't leak out the nitrogen. I've always wondered this. Also note that while the accumulators are the same physical size front and back they have different pressure inside. . . . so don't swap them on accident . . .

 

[grinchy]

Damping voodoo

 

[UCrazyKid]

Jackpot! Thanks @grinchy

 

[tincan45]

UPDATE: Added SLS video in OP for future reference. Thanks @grinchy for the new tech data!

 

[HGB]

McLaren's MP4-12C’s also uses a flavor of Tenneco's Kinetic Suspension.

WRC and Dakar race teams used the system, only to be banned as an unfair advantage in 2006.

The system fitted in the LX 570 is more broadly capable and complex than any of those flavors.

I'll post more when I'm home later.

Any more info on the wrc dakar ruling? Very cool story!