LX570 AHC “Basics” - Added as sticky thread for AHC Issues (9 Viewers)
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now. Come, pitch a tent. Its cozy here.
Soooo, that sounds like a yes. TeCK?
I don't buy into swapping springs. It's asymmetric by design and they probably had good reason. I prefer a 10mm spring packer on the low side.
Re-reading the AHC manual again, it does look like the system has some ability to compensate side to side via height offset. I couldn't get it to work perfectly but good enough.
Ok guys, for the sake of community understanding, and not argumentation. Teck knows i love him...;
All the reasoning went out the window when AHC was added in. Driveline torque, axle cycle motion, and weight compensation. None work under AHC theory.
Thats why my level was faulty and height offset was useless until it wasn't... Once the system was balanced.
Lift and unload are not done per corner, they are done per axle. AHC is not that smart and HOU is only a slightly less crude tool than sensor arms. You can see the calc compensation happen AFTER the axle is already lifted. Its bad. Plain bad and rudimentary and its all due to the ECU. Mechanically, its fantastic in every way.
So even if you don't believe there are parameters to control for pressure (wild IMO to take that stance, and utterly blatantly / obviously wrong). It will never work right until you balance the system. Its an inherent design flaw, and oversight, some can see it some might not want to think its possible for that kind of mistake. Never mind the myriad of other design issues that are present in the 200. Its just a reality of engineering. There is no perfection to be had.
You know I wont attempt to knock your reasoning Teck, but I will knock your sentiment sometimes in good fun.
And I wont knock but rather commend your loyalty to the brand and platform as well as your understanding and contributions.
There are 100% faults though we have to be able to accept. Im working on that personally with the help of the forum counselors LOL
My truth:
Truck is setup goofy from the gate. Every single one ive seen leans and the forum will attest to that. My example wasn't a hundred years old with a gazillion miles on it either. Wether new or aged system, Its just wrong, and AHC by design is symmetrically loaded. Makes ZERO sense to run offset springs in the rear.
Its a carry over from the LC, and actually not needed for LHD vehicles where driver weight is balancing the gas tank, steering column balancing AHC components, and battery balancing the jack and toolkit. When the truck is off, if your truck is leaning, you are overloading that corner ram its leaning into. When its on, and you cant get it to sit level, its because you are pressurizing the axle in tandem, where there is unequal load at each corner. I have solved this, as thoroughly as I can do for free. And if no one wants to give me a pat on the back, that is totally fine with me. I understand you have to be fed with silver spoon, and I have to write like its a published white paper for anyone to respect each others ideas in the modern day (ew). I dont even use proper grammar or punctuation, or spell check / auto correct. And I also realize it wont be received with thunderous applause, specially when its a Toyota fan club I'm writing in. I am totally fine with that, I have done my part, and if there are people who It can help out there, thats enough for me. I wont make it my job though to convince anyone.
In the end there are two things I firmly believe:
1) You really REALLY should not modify AHC. If you want a lifted truck, buy a Land Cruiser.
2) AHC itself is great, but it has severe limitations in logic and programming and user controls.
I can back those two statements up with a lot of facts and supporting arguments. But where I am now, is that all around, there is really no better suspension to be had that can do everything AHC does. Its just far from perfect.
For those reasons though I will probably eventually rip it out if anything ever fails. If not, ill run it into the ground. Gladly.
My only question at this point is how in the hell has a 4 corner scale we can use on a bone stock LX? I really need to know.
Just for those following along at home on pins and needles, I should re-emphasize someone's early advice to do the measurements on level ground. I took the measurements above in my driveway - at a fairly good nose-down slant.
I just re-measured today in the flattest spot I could find in a local parking garage and the left-to-right differences were 0.25-0.5" on the rear axle and 0.25-0.5" on the front. Passenger side was higher than driver. I also checked the average change from L to N and N to H at each axle, and they were "right close" to the specified -60/-50mm and +50/+60mm specified in the manual.
tl;dr, measured on flat ground and everything seems to be in-spec with a consistent 0.25-0.5" higher on the right side. Move along, nothing to see here.
Hello AHC gurus. I followed the procedure on this discussion and did the 5th accumulator first. Immediately after, I started the truck and let it run for about 2 minutes. I turned car off and noticed the system did not pull any fluid out of reservoir to refill 5th accumulator. I tried opening 5th accumulator bleeder again and nothing came out. I proceeded to do the other four corners twice following FL, FR, LR, RR. System self leveled each time after all four corners. I kept reservoir at max after each corner. After I finished, I then cycled truck to L, N, H a couple of times and all worked great (15 seconds from L to N). Checked reservoir and it had dropped below min after cycling to all heights so I am thinking it finally filled 5th accumulator but I have not opened that bleeder again to check. Drove truck for about 30 minutes and dampening seemed better and no codes or issues.
I’m just wondering why it took until I was finished and cycled to each height for the truck to finally fill 5th accumulator? Just seemed odd so I thought I would ask the group. Does the 5th accumulator only fill when going to L or H?
I’m just wondering why it took until I was finished and cycled to each height for the truck to finally fill 5th accumulator? Just seemed odd so I thought I would ask the group. Does the 5th accumulator only fill when going to L or H?
The accumulator generally only refills after a height change, I would call that expected behavior. I do think it's possible that the system checks the pressure in the accumulator, but the ECU certainly isn't constantly aware of it. I don't always monitor, but I did spend a few weeks driving around watching the AHC ECU with OBD Fusion after i set it up. One time, I'm fairly certain i saw the system "check" the pressure of the accumulator. The accumulator valve was reported on and none of the leveling valve were on, and I was not making a height change. Sadly, OBD Fusion refresh rate is pretty terrible, so I wouldn't call that finding a "sure thing".
Also, the 5th accumulator would have no effect on driveability. It's only function is to speed up the process of lifting the truck from L to N or N to H.
Does anyone know how much you can move the AHC pump? Thinking of relocating and making a bracket but noticed some hardlines.
If I recall there was someone who actually flipped it and moved to inside of frame rail but they made all custom lines. When installing my dissent i was surprised how much I could move it around.
I was able to move it around a bit but unfortunately the hardline prevents me from moving it anymore than half an inch or so in any direction
Just extend it with brake line if you really need to. Nothing major there to worry about, and you can bend and flare your own to custom length.
Has anyone had either corner of the truck start to get lower randomly?
Just noticed my driver side front is lower now.
Before I took measurements and adjusted heights in techstream now I am noticing the front right is .5-.75 lower.
Tire pressures the same
New AHC globes
No leaks from what I see
Height sensor is tight.
Is this a sign of a filing height sensor?
Just noticed my driver side front is lower now.
Before I took measurements and adjusted heights in techstream now I am noticing the front right is .5-.75 lower.
Tire pressures the same
New AHC globes
No leaks from what I see
Height sensor is tight.
Is this a sign of a filing height sensor?
Apologies if I overlooked it earlier in this thread, but is there a consensus on the best place to source AHC fuid?
So I preface all this in that I can't tell if the ride is less smooth than it used to be or it's in my head / driving more on s***ty roads.
I had the fluid changed about 3 months ago. Seemed to make a slight difference on road but the AHC now responds much faster lowering and rising. In my mind, it still feels like perhaps a globe change would be good to do since I'm nearing 150k anyways.
If I do a globe replacement should I be swapping the fluid again? or do I just top off?
Thanks,
I had the fluid changed about 3 months ago. Seemed to make a slight difference on road but the AHC now responds much faster lowering and rising. In my mind, it still feels like perhaps a globe change would be good to do since I'm nearing 150k anyways.
If I do a globe replacement should I be swapping the fluid again? or do I just top off?
Thanks,
If the fluid that comes out of the bleeder is clean, you can catch it and reuse.
Thank you. Copy that.
My 2011 LX has 140kmiles, over the recent past I feel like the suspension has gotten soft and spungy, feels like a traditional suspension does when the shocks need to be replaced, is this an accumulator replacement or shocks too? I don’t see any leaks anywhere, fluid was changed 2 years ago at 100k miles
Some dampening happens in shocks, most dampening happens in accumuatlors. I had replaced both shocks and accumulators by 140k fwiw.
Thanks! I will do both, dealership here I come, my long time mechanic will not touch the hydraulic suspension
