LX570 AHC height modifications (lift it!) (48 Viewers)
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Thanks! I realize that techstream only shows 1 pressure value on my LX570. It would show 5 pressure values on my LX470. I suppose I have a lot to learn about the LX570 and the changes to the AHC system.That's how the manual reads, but it is 1800 pages.
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Thanks, i was asking about this info in the AHC basics thread. I copied this info over to that thread with a link.
Is there any word from the FSM or anywhere else about how much fluid should be displaced when lifting the truck from "L" to "H"? I read in the 100 series thread something like at least 7 lines and the person who was doing the test had something like 10 lines displaced.
I did a fluid service on my LX570 this weekend and found graduation marks on the front and rear side of the tank. On the front side, there were not enough marks to accommodate a movement of more than 8 lines and on the rear there was 13 lines, but they began and started well above and below the min/max lines. I assume this is normal and that you want the height of fluid to be between MIN/MAX while in "N" height mode.
In the 100 series forum this is supposed to be a good test of the wear on your accumulator globes.
Front tank lines. Can't see in real life without removing wheel, but easy to shove camera into opening and take picture.
Rear Tank lines. I believe the two upper long lines are the MIN/MAX and then there are 13 level marks. Also, difficult to see without shoving a camera into a tight space. I removed my spare tire to get more access.
I did a fluid service on my LX570 this weekend and found graduation marks on the front and rear side of the tank. On the front side, there were not enough marks to accommodate a movement of more than 8 lines and on the rear there was 13 lines, but they began and started well above and below the min/max lines. I assume this is normal and that you want the height of fluid to be between MIN/MAX while in "N" height mode.
In the 100 series forum this is supposed to be a good test of the wear on your accumulator globes.
Front tank lines. Can't see in real life without removing wheel, but easy to shove camera into opening and take picture.
Rear Tank lines. I believe the two upper long lines are the MIN/MAX and then there are 13 level marks. Also, difficult to see without shoving a camera into a tight space. I removed my spare tire to get more access.
Did you ever get anything figured out on this question. Now I'm starting to think we are adjusting the rear level sensor for the headlights. I'm not sure if that's the same sensor as the AHC, or if they are both back on that corner and we are just finding the wrong one first. The one I adjusted looks like your's. I was coming here to try to figure out if it had been banged up or something because it doesn't look like any of the other 3 sensors.
Well, I climbed under mine. Definitely only one sensor in that side and with better angle looking at it, I’m pretty sure mine isn’t bent weird or anything. So I think it’s normal.
In the world of the 100 Series Lexus LX470, Japan 4x4 made a set of spacers that would mount between the shock mount on the rear axle and the AHC ram, and between the lower control arm and the AHC ram in the front. The purpose of the shock was to maintain the stock amount of travel (up and down), while producing a lift. The AHC sensors would be used to adjust the lift size.
I'm not a suspension expert, but it seems to me that a LX570 sensor lift extends the neutral distance that the ram travels, leaving less down-travel and more up-travel than the stock position at any given height (L/N/H). Generally, the suspension seems very similar to the LX470 series, but I think the LX570 series has a larger range of total travel. However, if someone were to fabricate a similar set of spacers for the front/rear of the LX570, then the down-travel/up-travel might remain similar to stock (also similar pressure), while still achieving lift.
Has anyone attempted to fabricate spacers for the lower shock eyelets to be used in collaboration with a spacer lift? Here's a picture of the spacers on a LX470 series. The front ones from an LX470 certainly wouldn't fit the LX570 LCA's, but the rear one might fit the LX470 axle mount... Is the up/down-travel less of an issue on the LX570 because of the additional travel vis-a-vis the LX470? am I overthinking this? Do the upper spring spacers on the front accomplish the same thing?
[Edit: After looking at the LCA on the LX570, I don't think it's possible to extend they eyelet's without running interference with the LCA itself. Maybe the upper spring spacer is the best bet...]
I'm not a suspension expert, but it seems to me that a LX570 sensor lift extends the neutral distance that the ram travels, leaving less down-travel and more up-travel than the stock position at any given height (L/N/H). Generally, the suspension seems very similar to the LX470 series, but I think the LX570 series has a larger range of total travel. However, if someone were to fabricate a similar set of spacers for the front/rear of the LX570, then the down-travel/up-travel might remain similar to stock (also similar pressure), while still achieving lift.
Has anyone attempted to fabricate spacers for the lower shock eyelets to be used in collaboration with a spacer lift? Here's a picture of the spacers on a LX470 series. The front ones from an LX470 certainly wouldn't fit the LX570 LCA's, but the rear one might fit the LX470 axle mount... Is the up/down-travel less of an issue on the LX570 because of the additional travel vis-a-vis the LX470? am I overthinking this? Do the upper spring spacers on the front accomplish the same thing?
[Edit: After looking at the LCA on the LX570, I don't think it's possible to extend they eyelet's without running interference with the LCA itself. Maybe the upper spring spacer is the best bet...]
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I like that you’re thinking outside the known 570 box even if it’s a carryover from 470 parts. I’m not sure about the front but I would think that would work in the rear as long as you protected the shock from over compression. Possibly an extended bumpstop. If I am visualizing it properly, this would reduce your up travel but extend your down travel by the amount of the bracket which should be fine as long as it doesn’t extend enough to loosen the coil.
I had commented about a similar thing over on a build thread, but I prefer this particular design rather than building a higher mount. Seems viable in my case since I plan to reduce my up travel anyways to eliminate any rubbing with a larger than normal tire.
Thanks for sharing the idea.
I'll go back on what I said. After further review, I think a front mount for the LCA is possible, it will just require a decent bit of fabrication. However, it might be a lot easier to put a shock spacer in the top, as @TeCKis300 did here Front Shock Spacer - Increased Suspension Stroke? - https://forum.ih8mud.com/threads/front-shock-spacer-increased-suspension-stroke.1098556/post-12820947 . I believe that this achieves the same thing without having to fabricate a metal spacer on the LCA, for the front. However, an LCA mount would likely be easier to install. Where @TeCKis300 achieved spacing of ~0.75" droop at the hub, I think an LCA spacer would have to result in more at the hub. In any event, I think it is doable, and might warrant further exploration. The sway bar links may also require extension, if the increase is more than an inch or so.
On the rear, the Japan 4x4 spacers for the LX470 series might actually fit the LX570...I haven't test fit yet, but it looks promising. The attaching bolt PN 9090119052 is the same on the LX470 and LX570, which leads me to believe that the rear AHC ram on both models has the same diameter hole, attaching the ram to the axle. The rear springs should probably also have a spacer added to them, since the springs would be extended via a shock spacer. There's probably more calibration that needs to be considered on the ideal shock spacer size (eye to eye) and the matching spring spacer.
For greater clarification, the intention here is not to provide additional lift via spacers, but to return the neutral pressure to stock and maintain the same up/down travel as stock, when implementing an AHC lift.
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I'm not a suspension engineer, but since the strut is not used to measure the height, (the sensor is mounted between the body/frame and the UCA) I can't see how spacing from the top or bottom of the strut would make any difference. On the rear, the easiest option is to only space out the spring, and spacing the spring should relieve pressure from the AHC. I suspect the biggest question is whether the shock ram arm has enough room in it's stroke to handle the AHC lift. It seems like one of the threads examined this (either the rear suspension rebuild or one of the other lift threads) and deemed there to be plenty of room on the shock arm to account for the 1-2" lift we are talking about here. This almost has to be true considering that the system can lift upwards of 3" with no ahc lift. I guess the question is, once you do an ahc lift...can it go to 4"-5", if not, then extended the length of rear shock unit would probably bring that back into spec. Sorry, if I'm just restating the obvious. I'm pretty new to all this, so maybe just working it out in my head rather than providing any new content.
Also, not that the neutral pressures don't exist in the 200 series, it's a little disappointing that they aren't measured and displayed in techstream. I know the AHC control unit didn't "use" the neutral pressures to change any settings in the 100 series suspension height, but it seems like that was a great metric to determine how well your system/suspension was working/aging. In the 200 series the only pressure sensor in the entire AHC system is the one after the pump where it pressurizes the system. It would be nice to know what the pressure was on each subcomponent at varying suspension heights like you could see in the 100 series.
I did the ahc lift on my 2010, with a very unscientific maxed out setting front and rear and i did not like the way that felt. I did not leave it long enough to get a alignment. I drove it that way for about a week, then moved it back. I've been slowly working to level out my suspension left to right and then even out the rake a bit, but haven't gotten there yet. It would be nice to see how all these changes have affected the neutral pressures. I don't think I'll try to do any ahc lift in the future until I get the spacers for at least the front.
Also, not that the neutral pressures don't exist in the 200 series, it's a little disappointing that they aren't measured and displayed in techstream. I know the AHC control unit didn't "use" the neutral pressures to change any settings in the 100 series suspension height, but it seems like that was a great metric to determine how well your system/suspension was working/aging. In the 200 series the only pressure sensor in the entire AHC system is the one after the pump where it pressurizes the system. It would be nice to know what the pressure was on each subcomponent at varying suspension heights like you could see in the 100 series.
I did the ahc lift on my 2010, with a very unscientific maxed out setting front and rear and i did not like the way that felt. I did not leave it long enough to get a alignment. I drove it that way for about a week, then moved it back. I've been slowly working to level out my suspension left to right and then even out the rake a bit, but haven't gotten there yet. It would be nice to see how all these changes have affected the neutral pressures. I don't think I'll try to do any ahc lift in the future until I get the spacers for at least the front.
Interesting you bring up the 100-series rear shock extension bracket. I've long thought to try that and may still one day.
If neutral pressure restoration (to maintain or increase payload capacity) is the objective - yes, solution is as you mention and I've done both front and rears. Front with upper OEM shock spacer. Rear, I now have 30mm spring spacer. I've AHC lifted my LX about 1" front and .75" rear. So the front spacer was to restore pressure. Rear to restore, and augment for further load. It all works great up to about 2000lb payload. I've since added airbags too to the rear for kicks and will see how it goes.
Extending suspension travel - the shocks are the down limiter for travel front and rear. The spacer at the front indeed increases suspension stroke by about .75", to 10" total travel matching the rear. Rear spring spacers don't do anything for travel. Anyone want to try that 100-series bracket? Will want to pay attention to make sure that the shock does not become the compression limiter at full squish.
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In regards to extending travel at the rear...
There's been some interesting development where some have relocated lower shock mount upwards on the OEM bracket by reusing a higher up stock hole, welding additional supports, and using a through bolt. This could be a strategy to increase droop by about 2". Provided the shocks don't become a limiter upon compression. Perhaps combining this with a mild bump stop lowering.
forum.ih8mud.com
forum.ih8mud.com
There's been some interesting development where some have relocated lower shock mount upwards on the OEM bracket by reusing a higher up stock hole, welding additional supports, and using a through bolt. This could be a strategy to increase droop by about 2". Provided the shocks don't become a limiter upon compression. Perhaps combining this with a mild bump stop lowering.
(Rear) lower shock mount mod
I don't believe that most of you would have a need for this mod but for those of you who do it's an easy option. So how I got here, I went with the torflex rear coils from tough dog. They netted me approximately 4 inches of lift, just guessing here. And my truck is light in the rear which...
forum.ih8mud.com
Builds - 2010 LX 570 -AHC Delete, Tundra Swap, 4.5" BDS Lift
do you need to drop the rear bump stops at all with that lift?
forum.ih8mud.com
Conceptually, that would achieve the same increase in droop, without impacting up/down travel, vis-a-vis stock. If the intention is to keep the AHC ram travel close to stock, the adjustment may have to be kept to around the max AHC height increase possible via the sensor lift.In regards to extending travel at the rear...
There's been some interesting development where some have relocated lower shock mount upwards on the OEM bracket by reusing a higher up stock hole, welding additional supports, and using a through bolt. This could be a strategy to increase droop by about 2". Provided the shocks don't become a limiter upon compression. Perhaps combining this with a mild bump stop lowering.
(Rear) lower shock mount mod
I don't believe that most of you would have a need for this mod but for those of you who do it's an easy option. So how I got here, I went with the torflex rear coils from tough dog. They netted me approximately 4 inches of lift, just guessing here. And my truck is light in the rear which...
Builds - 2010 LX 570 -AHC Delete, Tundra Swap, 4.5" BDS Lift
do you need to drop the rear bump stops at all with that lift?In regards to extending travel at the rear...
There's been some interesting development where some have relocated lower shock mount upwards on the OEM bracket by reusing a higher up stock hole, welding additional supports, and using a through bolt. This could be a strategy to increase droop by about 2". Provided the shocks don't become a limiter upon compression. Perhaps combining this with a mild bump stop lowering.
(Rear) lower shock mount mod
I don't believe that most of you would have a need for this mod but for those of you who do it's an easy option. So how I got here, I went with the torflex rear coils from tough dog. They netted me approximately 4 inches of lift, just guessing here. And my truck is light in the rear which...
Builds - 2010 LX 570 -AHC Delete, Tundra Swap, 4.5" BDS Lift
do you need to drop the rear bump stops at all with that lift?
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Is the max AHC height increase 1.5" or is more possible via moving the sensors + techstream adjustments? Just tossing around ideas...
There's plenty of bandwidth in the sensors to lift, using a combination of stock bracket adjust, techstream offset, and additional bracketing.
The concerns are maintaining neutral pressure to maintain good payload handling. Other big item is to make sure there's enough droop travel as pegging out the suspension in high mode without much droop travel can actually be a hindrance offroad with poor articulation.
The concerns are maintaining neutral pressure to maintain good payload handling. Other big item is to make sure there's enough droop travel as pegging out the suspension in high mode without much droop travel can actually be a hindrance offroad with poor articulation.
Poor articulation and an overly harsh ride
How's the 37s coming? I think this lower shock mount maybe just the mod you need. Along with a 1-2" lowered bump stop. Should be able to set the AHC sensors to just about stock with these physical changes.
Thanks for pointing out those threads!
That’s exactly what I’ve been thinking since I saw @Atwalz build. Then you shared the other link that I hadn’t seen but I kind of like his approach with a bolt through. Which do you prefer and why?
I sent my rear bumpstops to Curtis @ Durobumps a couple months ago. He said he would make me a set for sending him my oem. But I’m not sure if I’ll see them now. Hopefully soon. Maybe he’s at KOH currently having fun slinging more bumps. I planned on taking his design and figuring out how to extend it, but haven’t heard from him for over a month.
Not much progress on the 37’s. Got all five of them mounted on the freshly powder coated beadlocks. Swung by my fabricator that I felt comfortable doing the new front cab body mounts and let him look at my ideas. (New body mount further back but not interfering with the AHC components/protection) He is very busy and asked for a couple weeks to think about it. I understand there are liability concerns to consider and, of course, I want it to be as safe as possible with the change, so I’m not pushing him.
One of my 37’s & beadlocks only took 2.5oz of weight to balance! I think I can improve that even a little more with two TI beadlock bolts around the valve stem. The weight was required exactly opposite the Apex quick deflate stems. Just a fun little thing to try while I wait for other progress.
Both approaches look sound and should work fine.
If we're teasing at details, the stock setup looks best with a separation of concerns between the structural mounting post, and clamping pressure provided by an end bolt. The single shear configuration is more difficult to ensure long term durability. The stock configuration puts the shaft in compression rather than a single straight bolt through that is in tensile.
Which is why I think if there's any concern at all, that a double sheer support could be created for the new mount by tying it back to the original shaft at the ends.
If we're teasing at details, the stock setup looks best with a separation of concerns between the structural mounting post, and clamping pressure provided by an end bolt. The single shear configuration is more difficult to ensure long term durability. The stock configuration puts the shaft in compression rather than a single straight bolt through that is in tensile.
Which is why I think if there's any concern at all, that a double sheer support could be created for the new mount by tying it back to the original shaft at the ends.
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What tire / wheel size combination worked well for you with little or no trimming?
