Long Travel AHC (2 Viewers)

[TN LX570]

The accumulator part numbers are different by a digit.
LX570: 4914160020 and 4915160020
LX600: 4914160040 and 4915160040

Let’s hope the original ones will cooperate as I don’t think the 600 ones are available on eBay Japan at the bargain rate.

They certainly look similar.

 

[MTKID]

I need a free weekend to pull some more dimensions and numbers from my old shocks...

And get to cutting open your old shocks

I’m really excited for this option of LX600 shocks since I think just a little bit longer on the rear would give me exactly the droop I’m looking for

 

[grinchy]

so, reading between the lines on these last few posts, the LX600 has longer stroke shocks, which means it likely has longer springs too? So now there is a 'lift kit' for LX570s? Assuming of course the plumbing cooperates (or can be adapted)?

 

[tbisaacs]

Kinda cool to see that mechanically AHC remains the same between 570 and 600. Speaks to the robustness of the system vs how much was changed between 100 and 200 series.

 

[lx200inAR]

Here's a short list of differences between the two systems:

J200	J300
AHC was offered for both Toyota Land Cruiser (although this version was not available in all markets) and Lexus LX	Initially, AHC is offered only for Lexus and is not available for Land Cruiser
Spring rate (stiffness) control was applied to the front wheels only	Spring rate control with three pneumatic chambers is used for all wheels
There was a pump accumulator for a faster change in the suspension height	No common accumulator
Single control valve unit was used	Two valve units are installed, for the right and left side (the pressure/temperature sensor and the cut valve are in the right side unit)
Coordinated operation of the all shock absorbers was performed via central hydraulic cylinder	Shock absorbers have independent electronic control
Suspension height range was +70/-60 mm for the front and +80/-40 mm for the rear	Height change range is +85/-25 mm, at automatic extra-mode the lift height is increased to +105 mm

So looks like the new system is designed to go a bit higher. But i agree...the primary difference is they took out the central control cylinder that was a passive system to control lean and replaced it with active control at each corner, and added the high spring rate accumulator to the rear axle. Other than that, it's all pretty similar.

 

[grinchy]

Shock absorbers have independent electronic control

This new feature might get in the way of a 1:1 swap.

 

[TN LX570]

This new feature might get in the way of a 1:1 swap.

Maybe. There’s no electronic connection on the shock itself, so I’m assuming that’s referring to a part that is regulating the fluid going to the shock.

 

[lx200inAR]

Maybe. There’s no electronic connection on the shock itself, so I’m assuming that’s referring to a part that is regulating the fluid going to the shock.

That control is in the actuator where the accumulators are attached.....

The 200 also has electronic control, but I believe they are trying to differentiate the mechanical control of the central cylinder (+ the electronic control) on a 200 vs increasing/decreasing spring rate using electronic control only at the actuator on the 300 (since there is also a high spring rate accumulator at all 4 corners now the system can provide increased control at each corner).

Hopefully that makes sense.

 

[Jason Andrews]

Forgive my ignorance, but I have to ask. Where is everyone measuring travel from if they are getting 12.5" of travel on the rear suspension? The stock rear shock looks to have 8.5" max from the data posted.

 

[lx200inAR]

Forgive my ignorance, but I have to ask. Where is everyone measuring travel from if they are getting 12.5" of travel on the rear suspension? The stock rear shock looks to have 8.5" max from the data posted.

It’s not a 1:1 ratio because the tire is on an arm away from where the shock is and there is radial motion of the suspension. I’m sure I would screw it up if I tried to expound any more of the concept than that, as I dont fully visualize how it all works as a system well enough to explain it. It’s a little more simple to visualize on the front end.

 

[TeCKis300]

Forgive my ignorance, but I have to ask. Where is everyone measuring travel from if they are getting 12.5" of travel on the rear suspension? The stock rear shock looks to have 8.5" max from the data posted.

Ideally measured at the wheel itself, eliminating any geometry factors.

Stock 200-series rear travel is spec'd at 10" . 9" front.

More info here

Suspension Travel Comparison

Been meaning to do this to get some objective numbers to compare ride height versus droop travel versus compression travel. What better to do on a rainy day. Hope is that others may contribute and I'll update my table. We've known for awhile that some aftermarket suspensions increase what is...

forum.ih8mud.com

 

[04UZJ100]

The accumulator part numbers are different by a digit.
LX570: 4914160020 and 4915160020
LX600: 4914160040 and 4915160040

Let’s hope the original ones will cooperate as I don’t think the 600 ones are available on eBay Japan at the bargain rate.

They certainly look similar.

View attachment 3116507

Folks over in the 100 series section were able to decipher what the part number meant and who the actual OEM was. Some thread over there has the information.

I bet they're mechanically identical with some slight changes to the N2 precharge pressure due to the difference in vehicle weights. Wouldn't be surprised if they work as a viable option for the LX570 assuming you're not pushing the limits. @TeCKis300 has shown they're capable of handling and pushing the stock GVWR so would expect the 600's to be up to the task.

 

[lx200inAR]

Doesn’t the LX600 weigh a few hundred lbs less than an LX570? May not be an “upgrade” for a 200 series.

 

[04UZJ100]

Doesn’t the LX600 weigh a few hundred lbs less than an LX570? May not be an “upgrade” for a 200 series.

Didn’t say it was an upgrade. Said that the 570s are capable of more than thr GVWR if the vehicle. Meaning the 600s could probably used as a substitute in 15 years in the 570s cannot be found.

 

[lx200inAR]

Didn’t say it was an upgrade. Said that the 570s are capable of more than thr GVWR if the vehicle. Meaning the 600s could probably used as a substitute in 15 years in the 570s cannot be found.

I suspect I was responding to the general gist of this thread and the idea that LX600 globes may be better for long travel on a lx570.

100 series globes are still available, as well as old MB and Citroen as far as I know. I suspect it will be a while before a lack of replacements is an issue. Also there are/were companies who were rebuilding Citroen globes to work on 100 series. I suspect when we get to that day, there will be some smart person out their who comes up with a replacement.

 

[AnyMal]

Subbed but curious about the 600 new rear shock angle difference will come into play during fitment. Could explain length variance as well.

currently looking for a clean way of extending rear travel to account for lift.

 

[TeCKis300]

Correct. 30 to start, I highly doubt a stock arm cruiser will ever produce enough droop to blow out a cv on the down stroke. But who knows. I find the sway bar to be the limiting factor in a substantial way.

30mm and the upper control arm just touched the coil at full droop. I’m hoping that the 24mm will position me between the spring coil. If that’s the case it will actually produce more droop without a front sway bar. Uniball uppers without a sway bar would be the next step.

I think with the front sway bar mounted. Anything over 18mm serves zero purpose in increasing droop.

For what it’s worth. I’ve been beating the hell out of this front end for a few months now and no sign of wear, failure or binding.

Bringing this conversation in from the general thread. That's great info!

I'm at 17mm with stacked spacers and I did notice the sway links are at about the end of their travel in the droop position. Are you currently running sans front sway?

Would it be as easy as spacing down the sway mounts on the frame by a 1/4"? Or finding some extended sway end links?

I think if I were to do this again, I'd run 2x stacked OEM LC spacers for 20mm. Though the 24mm Tundra spacer would be such an easier install, and maybe just space down the bump stops with larger aftermarket stops in both positions, or spaced down with a large washer.

 

[Jason Andrews]

I think if I were to do this again, I'd run 2x stacked OEM LC spacers for 20mm. Though the 24mm Tundra spacer would be such an easier install, and maybe just space down the bump stops with larger aftermarket stops in both positions, or spaced down with a large washer.

I was told from multiple people that stacking 2 of the OEM LC spacers is not a good way to do it, not correct, or impossible. Can’t quite remember, but it was a resounding don’t do that IIRC.

 

[MTKID]

I was told from multiple people that stacking 2 of the OEM LC spacers is not a good way to do it, not correct, or impossible. Can’t quite remember, but it was a resounding don’t do that IIRC.

Can’t imagine any harm if you made sure the top bolts are long enough and you protect yourself from over compression with adjusted bumpstops.

We’re installing the Westcott kit right now. So I'm removing the OEM spacer to put in the Westcott top spacer. 12.8 mm vs 10mm

 

[TeCKis300]

I was told from multiple people that stacking 2 of the OEM LC spacers is not a good way to do it, not correct, or impossible. Can’t quite remember, but it was a resounding don’t do that IIRC.

Well...this whole thread is breaking ground on how and how far to do this. For an LC, I wouldn't recommend it and perhaps that's where it's coming from. The hive mind is understanding that when stacking spacers with aftermarket shocks, that it starts pushing durability of CVs.

AHC is a different animal and we're trying to maximize droop and travel with stock shocks, so adjusting the spacer stack is it. We're starting to get some more concrete info as what is okay and what is too much.

I went conservative when doing mine so I'm on a 17mm stack. I've definitely slammed the front suspension hard into bumps on several occasions bombing through the desert with my Raptor buddies. No damage to the shock. (aside - remember to set shocks to sport when running hard)

Based on @Killacaviar 's input, I think he's saying 24mm might be okay, but there will be limiting factors (sway bar) ahead of full droop. And that he believe 18mm is what has utility without messing with sways.

Here's where I'm landing that a double stack of LC spacers - 20mm, might be workable with some extension of the sway bars.

@TN LX570 looks to have made a great video to help here

https://www.youtube.com/@DaveyJordan