AHC Lean (1 Viewer)

Does your AHC lean


  • Total voters
    18

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.

AnyMal

no quema cuh
Joined
Oct 15, 2019
Threads
31
Messages
3,350
Location
H-Tine
After walking away from this for some time due to life getting in the way, I really want to find a solution for my lean.
Ive noticed MANY LX around town exhibiting the exact same drivers side lean. I look at all of them i see... Its mostly 2016+ but ive seen it on all years even LC.
Ive tried adjustments in tech-stream, adjusting the brackets and every permutation of this. The lean always settles the same way.
Ive done it by the book to the t, with jacking and leveling and the dealership is refusing to investigate after a couple of visits and claims its within spec.
If it does go away, its temporary or janky at best. As if the computer is stubborn to level out as adjusted in height offset and just drops one wheel when it wants.
By the way this is with both with a full or empty tank.

My vehicle also settles when parked with an audible whine from an AHC component or valve releasing when we leave the vehicle.
The rear lowers as if excess pressure is relieved but it doesn't always sound smooth. Most of the time it sounds like a valve is partially opened and whining.
Is anyone else experiencing this? Is it normal?

Has anyone succesfully resolved this issue?
Ive seen multiple posts about people giving up from my previous research and some with no issues getting the ECU to accept whatever values they input.


1.jpg
 
How much offset is there between the two sides? Looks significant in the picture, maybe a bit more than 1"?

Like KDSS lean, AHC lean may be a red herring. What I'm getting at is that 4x4s have leaned since the beginning of time, and is somewhat their nature when having large suspension travel and slinky springs.

It's totally possible there's something more insidious. But it inevitably happens that a weaker coil spring in a spring set, take a bit more load. And with more and more lean over time, takes increasingly more load and deflection until it becomes a visible nuisance.

My '06 LX470, and my '09 LX570 have both leaned over the years. In the LX470, it was super easy with adjustable torsion bars. In the LX570, and as with every other 4x4, a solution can be trim packers (spring spacer shim). Put a 5 or 10mm trim packer in the rear corner that is low, and that'll fix it.

To clarify, it's the coil springs that weakens over time, and a trim packer will directly address that. Shouldn't use AHC (or KDSS on LCs) to correct for lean.
 
How much offset is there between the two sides? Looks significant in the picture, maybe a bit more than 1"?

Like KDSS lean, AHC lean may be a red herring. What I'm getting at is that 4x4s have leaned since the beginning of time, and is somewhat their nature when having large suspension travel and slinky springs.

It's totally possible there's something more insidious. But it inevitably happens that a weaker coil spring in a spring set, take a bit more load. And with more and more lean over time, takes increasingly more load and deflection until it becomes a visible nuisance.

My '06 LX470, and my '09 LX570 have both leaned over the years. In the LX470, it was super easy with adjustable torsion bars. In the LX570, and as with every other 4x4, a solution can be trim packers (spring spacer shim). Put a 5 or 10mm trim packer in the rear corner that is low, and that'll fix it.

To clarify, it's the coil springs that weakens over time, and a trim packer will directly address that. Shouldn't use AHC (or KDSS on LCs) to correct for lean.

Thanks, doesn't the factory spring set come with a variance "for the fuel tank weight"?
What were to happen if one were replaced with the taller matching coil spring?

The height varies L-R from .5" to .75", which if i remember correctly, the former is "within spec". Nonsense.
 
Here is an image from another thread on springs.

Does anyone know why Toyota uses the same springs as the LC in an LX with AHC? I don't understand the requirement given that AHC is constantly trying to level itself.
Doesn't that seem counterintuitive? It would seem that one of the rear shocks will be doing more work and need to be at a higher pressure in this configuration...
 
I've had mine settle sometimes after shutting it off. Kinda like how it adjusts while sitting at a stoplight, though it's mainly the incline of where I end up parking. There's several areas of my commute where I know it'll do it. That seems to be a normal LX thing.
When I leveled out the front rake I also fixed the lean. Raised the physical sensors to be even, and did the fine tuning on techstream. It was a combination of raising the FRs value while also decreasing the FLs value. I didn't mess with the rears sensors or values at all. Make sure to save your old values and to mess with it on level ground. I'd cycle through low and high, bounce corners, and then measure to see where it'd end up. Process took a while but I ended up getting it 1/4th" to 1/2" difference.
 
Here is an image from another thread on springs.

Does anyone know why Toyota uses the same springs as the LC in an LX with AHC? I don't understand the requirement given that AHC is constantly trying to level itself.
Doesn't that seem counterintuitive? It would seem that one of the rear shocks will be doing more work and need to be at a higher pressure in this configuration...

They do not have the same springs between LC and LX.
 
How much offset is there between the two sides? Looks significant in the picture, maybe a bit more than 1"?

Like KDSS lean, AHC lean may be a red herring. What I'm getting at is that 4x4s have leaned since the beginning of time, and is somewhat their nature when having large suspension travel and slinky springs.

It's totally possible there's something more insidious. But it inevitably happens that a weaker coil spring in a spring set, take a bit more load. And with more and more lean over time, takes increasingly more load and deflection until it becomes a visible nuisance.

My '06 LX470, and my '09 LX570 have both leaned over the years. In the LX470, it was super easy with adjustable torsion bars. In the LX570, and as with every other 4x4, a solution can be trim packers (spring spacer shim). Put a 5 or 10mm trim packer in the rear corner that is low, and that'll fix it.

To clarify, it's the coil springs that weakens over time, and a trim packer will directly address that. Shouldn't use AHC (or KDSS on LCs) to correct for lean.

Howdy yall, if you are using AHC HOU or sensor adjustment to modify lean, please follow Teckis' advice. Not only is that a bandaid, but im seeing more and more mentions of rear shocks leaking or weeping as well. I just wanted to briefly address this since I've now solved it after a year of struggling with it and im glad i listened to the advice above to get where i am today.

I recently got to take this issue (coincidentally) to a very high level resource at Toyota. Im not here to make claims on my own behalf or anything else so take my advice if its worth it to you and if not, i wont loose any sleep over it.
For anyone wondering how to fix the drivers side lean, and almost every single '16+ LX ive seen around town has it let me make it easy for you.

Order yourself a rear right coil spring, and replace the rear left with it. Thats it. The part number is 48231-60D31.

This is not a very simple procedure and there are fine folks here with multiples more years of experience than I that can help you perform this fix.
The only caveat i can add to any existing LC write-ups is with the LX AHC shock you need to bleed the nipple on the drivers side to be able to remove it from the shock mount. After doing the swap, my advice would be do any sensor or HOU adjustment and balancing while all the bolts and bushings are free, then to "stabilize" the suspension again and do the final torque when you are happy with it.

I find the rear end is more stable and linear in compression and it has also reduced my excess body roll on right turns which always bugged me.
My HOU calibration took immediately and it does not have the annoying delayed pressure adjustments it once had to do when lifting from L to N.
If you happen to be sensor lifted, this and front shock spacers will get your AHC a bit less stressed as well.

Happy to answer any questions if i can.

Screen Shot 2021-10-27 at 10.36.45 AM.png
 
Howdy yall, if you are using AHC HOU or sensor adjustment to modify lean, please follow Teckis' advice. Not only is that a bandaid, but im seeing more and more mentions of rear shocks leaking or weeping as well. I just wanted to briefly address this since I've now solved it after a year of struggling with it and im glad i listened to the advice above to get where i am today.

I recently got to take this issue (coincidentally) to a very high level resource at Toyota. Im not here to make claims on my own behalf or anything else so take my advice if its worth it to you and if not, i wont loose any sleep over it.
For anyone wondering how to fix the drivers side lean, and almost every single '16+ LX ive seen around town has it let me make it easy for you.

Order yourself a rear right coil spring, and replace the rear left with it. Thats it. The part number is 48231-60D31.

This is not a very simple procedure and there are fine folks here with multiples more years of experience than I that can help you perform this fix.
The only caveat i can add to any existing LC write-ups is with the LX AHC shock you need to bleed the nipple on the drivers side to be able to remove it from the shock mount. After doing the swap, my advice would be do any sensor or HOU adjustment and balancing while all the bolts and bushings are free, then to "stabilize" the suspension again and do the final torque when you are happy with it.

I find the rear end is more stable and linear in compression and it has also reduced my excess body roll on right turns which always bugged me.
My HOU calibration took immediately and it does not have the annoying delayed pressure adjustments it once had to do when lifting from L to N.
If you happen to be sensor lifted, this and front shock spacers will get your AHC a bit less stressed as well.

Happy to answer any questions if i can.

View attachment 2822743
I have the lean too now! I will take your advice!
 
I did a front sensor lift, maxing out the stock sensor adjustment. The passenger side went up 1/2-3/4" the driver side didn't go up at all, as far as I can tell. I have thought of using techstream height offset utility to try to sort it out, but I don't have the hardware or software and would need to call in a favor get some help doing it. At this point I'm about 85% sure I'm going to AHC delete, so I'm in a holding pattern.
 

Users who are viewing this thread

Back
Top Bottom