IMPOSSIBLE to LIFT LX570 or Remove AHC?? (6 Viewers)

[1world1love]

The whole debate just goes back to the 100 series AHC delete or not. Yes, the 200 series AHC is tougher and more robust, but the older LX570s have started to show some AHC problems here and there such as rusted out lines, sensors going, and its bushings needing to be completely replaced. AHC is also a system that is close to impossible to repair on the trail. Sure, its easy to say just buy a Cruiser but the Crusier sales numbers are far lower than LX570s.

These are all good and valid points.

I wonder if the trucks that are experiencing these issues were properly maintained? And I don’t imply that the owners didn’t take them for service regularly, but rather that the service techs may not always be as thorough as they should. The AHC is supposed to be serviced every 60k as far as I know, but that might just mean a fluid change in most cases. On the other hand, some of these issues might be difficult to detect under normal circumstances, but that could apply to many other systems as well.

Bad hoses and bushings aren’t unique to AHC for sure, and robust doesn’t mean indestructible. Those trucks are 10 years old now and likely to have a fair few miles on them.

How many times in 10 years would an aftermarket setup have to be rebuilt? How many components would we expect to have failed in that time frame?

Another thing is that I have yet to hear what a delete and replace might cost in real terms. And, because there is little data to go on, we don’t know how a delete really affects TCO. I suspect there are subtle, unintended consequences.

You are absolutely right about field repairs though. But again, the same can be said for many critical systems. I don’t know many people that carry around spare ECUs for all scenarios.

And you are right that the secondary market for LCs is about as tight as you can get. I looked for a year before deciding on my LX.

I guess my point is that if you want to mod the suspension, the LX might not be the way to go. For the time and money you put into deleting the AHC, you can likely find an LC and mod it. Also, as has been pointed out, you really lose a lot of value provided by the LX setup. I also think that a lot of people underestimate how capable it is.

To me it seems like a solution looking for a problem. To each his own though. I’ll certainly be interested to see it happen (and pass inspection here in Cali).

 

[grinchy]

Fancy multi stage setup like Icon is more than $5k exclusive of labor. New globes are $600 total. I bet for $5k you could redo every part of an ahc setup including the Ecu.

This argument has been had many times and in the end both Options are perfectly fine. Perhaps the biggest difference is that tlc owners start with $ for a 2 inch suspension lift and lx owners flip a switch.

From that point of view the lx is even more value.

At the very margin for a dedicated rock crawler obviously there are more options in springs. Of course at that margin there are many more vehicles which suit that purpose better.

 

[tbisaacs]

Ripping out AHC on the 570 would mean you end up with a rig that has less capability than both the TLC and 570. No leveling capabilities, no KDSS, etc. You'd have to spend $$$ for adjustable dampening. As others pointed out, you'd better off to buy a TLC and lift it.

 

[TeCKis300]

I'm a big believer in good suspensions having cut my teeth on road-racing and many sets of coilovers in my years of modifying cars. The thing with suspension is that it has be be dialed and tuned. For a specific setup, use, weight, and application. Street tuning is different than race tuning is different than compliance tuning, etc. How one is using the suspension matters. And that voodoo tuning part is more than the sum of some fancy shiny parts. The fact that so many aftermarket suspensions don't even come with the most important tuning recommendations (wtf?!) leaves a big part of development that is incomplete.

That's why I'm such a big proponent of AHC. It's a computer controlled dynamic hydro-pneumatic system able to constantly adapt to how one is using the vehicle. Off-road, towing, boulevard cruising, laden for vacation, etc. It's always setup just right for the use at hand. No single suspension, no matter how shiney or expensive, is going to touch what Lexus has done for the LX, for the broader set of uses the vehicle will see. Never mind how aftermarket suspensions, in all their beta/clunking/relying on end user tuning and need to be rebuilt 30-50k miles, simply doesn't hold a candle to the durability that the AHC system has proven to deliver with most examples easily going over 200k. And on-board maintainable with a fluid flush, try that with a passive suspension.

AHC is modifiable:

LX570 AHC height modifications (lift it!)

Does anyone think that the longer lengths of the already tested Tundra conversion would create too much leverage for the pressure of the AHC to still function properly with longevity? To the suspension, it wouldn't be much different then say, adding a front bumper. It's just more load. The...

forum.ih8mud.com

LX570 Augmenting for Load

I added a 10mm spacer to each spring at the rear axle. Intent is to add a bit more support to the AHC system, as I tow a heavy 27' Airstream travel trailer. This exact same mod could be done to an LC too, but will result in lifting ~1/2". While the LX570 never asked for it, this is a well...

forum.ih8mud.com

If one is racing or is tailoring their vehicle to a specific use - sure, makes sense as one can dial a suspension in to do that one thing better. But one may want to understand what their giving up when considering going back to the stone ages with static suspensions:

From Lexus:

New Lexus LX 570 has Adaptive Variable Suspension (AVS) for optimum active safety, ride comfort and a more natural driving feel.

Lexus AVS provides semi-active roll control of LX 570's monotube dampers for optimum ride comfort while maintaining high levels of vibration-damping performance, and a flat ride posture.

The AVS system allows the driver to select one of three suspension settings (Sport, Normal and Comfort) for optimum ride comfort and handling depending on the surface and driving conditions.

The Normal mode ensures driveability and stability, while emphasising ride comfort by controlling the damping force according to driving manoeuvres and road surface conditions.

The Sport mode increases damping force (both compression and rebound) at high piston damper velocities to further enhance driveability and stability.

The system provides a wide range of benefits in addition to driver selection.

It has advanced non-linear H-infinity control logic, to smoothly change the damping force to a target value according to changes in road surface or driving conditions.

The key advantage of non-linear control over the previous Skyhook strategy is that it dovetails with the non-linear characteristic of the damper units.

It provides a wider range of appropriate damper responses to the road conditions.

The difference is most noticeable in situations where a vehicle with passive suspension may experience wheel-hop.

With non-linear control, the AVS-equipped vehicle gives a smoother ride on rough road surfaces.

The system is designed to control the unnatural feeling created by the vehicle body running level on a bumpy surface.

The LX 570 AVS system also has:

• Thumping Sensitive Control: to ensure damper force does not increase while driving on rough roads.
• Large-amplitude Control: to decrease spring vibration when the suspension control ECU detects any large fluctuation in wheel stroke at low speeds.
• Roll-posture Control: to ensure stability and controllability during cornering, increasing the damping force and therefore reducing rolling movement.
• Anti-dive and Anti-squat Control: to maintain vehicle posture under braking and acceleration.
• High-speed Control: to vary damper force according to vehicle speed, to increase comfort at low speeds and maintain vehicle posture at high speeds.
• Absorber Control: to provide the three driver-selectable damper modes.
• L4 Range Control: to maximise comfort in off-road driving.

The AVS normally controls damper force in 16 steps. However, when L4 Range is selected, the AVS system manages damping force in eight intermediate steps if the vehicle is travelling at more than 55km/h, and in three steps when the speed drops below 55km/h.

 

[acoleFJ80]

Following- GX can be taken out, but not the LX. Would hate to downgrade to a GX...

 

[yOHda]

I think a lot of guys missed an important step on the way to the LX. Wheeling a built mini truck or FJ40. But this is an interesting discussion nonetheless.

 

[yOHda]

First ride with an ahc equipped vehicle just now. It is amazing, and quite fitting for a vehicle of this stature. I have nothing of value to really add to this conversation it seems.

 

[RHIN0]

Toying woth mine a bit

 

[Lummie]

Have you guys looked at this thread?

Disabling the AHC and AVS systems, no warning lights.

But can AHC make pigs fly? Not sure I'd try. Can't say I don't think back to the pic of your LX catching air @turbo8 Makes my pig fly, for about two seconds :) No pic however..

forum.ih8mud.com

 

[Michaelhook]

I have been searching high and low for an answer on this and cannot find much info at all. The LX570 has been out for a while now, yet there is apparently no aftermarket coil spring conversion kit or someway to replace the AHC with a proper lift kit for offroading. i've seen conversion kits for the GX460 but NOTHING for the LX570.

I'm close to buying an LX570 but this is holding me back. This type of hydraulic suspension has been known to fail in other vehicles (LX470) and when it does its very expensive to fix. I will be wheeling my truck pretty hard and would like to go ahead plan a replacement suspension swap for the AHC when it fails.

Has anyone removed the factory hydraulic suspension from an LX570 and replaced with a standard Land Cruiser style offroad coil spring lift kit? (ie KING/ICON/Old Man Emu)

Is there really no option available?

Thanks!

I used a Dobinsons AHC delete kit.

 

[jbyrd78]

I used a Dobinsons AHC delete kit.

How does it handle/ compare to the AHC system?