AHC Sensor Adjustment for Lift

uHu

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Hey there. New to the group. just got myself a 99 Lx470. Love her. This question may have been run ragged over the years but here goes... My question for this thing is; can you put aftermarket coils, shocks, and uca without deleting the ahc? For example.. the 2.5 medium load kit from old man emu. Can you put that on the rig and still run the ahc? If not.. why? Again. New to the lx family. Bear with me.
Read a bit ahc info here on the forum, and you'll see how it works.
Short answer is no.
With ahc, the coils and TBs take about half of the load, and the gas springs (accumulators, globes) take the other half through the shocks (which are not actually shocks even, just hydraulic rams). So, if you put OME springs on which take the whole load, the ahc will not work anymore, and you also have no damping.
 

hoser

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Hi all, has anyone done this AHC sensor mod that can report on it over a longer term? Much thanks.
I started this thread in 2005 and my AHC is still working using all original (1998) hydraulic components including the accumulators. The key is keeping the AHC pressure within the spec range. If you only adjust the sensors, you will place added stress on the system. I've expected the accumulators to require replacing for the past 5 years (based on age) but they are still holding up.
 
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For those who have done this, did you end up adjusting the t-bars, swapping rear springs, or anything else like that?

I'm just looking to adjust up 1.5" and set the pressures.
 

bhicks

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I added 30mm MAF rear spring spacers to help with the pressures. I turned the front t-bars while running tech stream software until the pressures were back to stock. That was a couple years ago so I don't remember the number of turns. it may be back in this thread somewhere. I think it was around 10 turns. It will vary depending on the age of your tbars.
 

PADDO

 
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@marcoLx470 When you raise the N height by adjusting the sensor N null point ~ aka sensor lift ~ then the hydraulics have to do more work to maintain the new height, this work equates to higher pressures and that is detrimental to ride quality and load carrying capacity. So, if you raise the front height 1 inch which is about as much as you can get by just sliding the adjustment all the way to the top of the slot, then your front pressure goes up about 2MPa and this needs to be compensated with approximately 10 cw turns on both adjusting bolts just to get your pressure back to something close to where they were pre adjustment. For the rear the pressure increase isn’t as significant, about 0.6MPa per inch. Basically if you lift front and rear 1 inch expect to put on 10 cw (tightening) turns for the front and expect to add a pair of 30mm coil spacers if you want to return pressures back to pre lift. For optimum performance of the dampening system you ideally need to know what those initial pressures are and ensure they are optimum (as opposed to “in spec” which is for people with low standards;) ). These numbers are from my own experiences, and should give you a basis to start.
 
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I used the spacer blocks that are 2" or ~51mm, so 35 will work. Work of advice, keep the lock nuts on there, those double direction 'bolts' for the hiem can back out and simple disappear. Not that I know anything about that...
 
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Dec 17, 2010
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I installed rear King Springs and now my rear AHC pressure is reading 4.9. Should I adjust the rear sensor down to increase the rear AHC pressure to spec? Is that even possible? Should i just leave it alone and wait for the springs to weaken on their own over time? Thanks for any input/thoughts.
 
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I installed rear King Springs and now my rear AHC pressure is reading 4.9. Should I adjust the rear sensor down to increase the rear AHC pressure to spec? Is that even possible? Should i just leave it alone and wait for the springs to weaken on their own over time? Thanks for any input/thoughts.
I believe you need to raise it to increase the pressure
 
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I wanted to level out my 2000 LX470 so I cut about a 1/4" off both ends of the sensor threaded rod and reinstalled it. Front end came up about 2- 2 1/2"s. Didn't do anything to the rear because I liked the original height of the rear. Now the problem is the front end bounces up and down like one of those Hip-Hop cars!! what did I do wrong and how do I fix it? Do I need to back off the torsion bars or what?
 
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I wanted to level out my 2000 LX470 so I cut about a 1/4" off both ends of the sensor threaded rod and reinstalled it. Front end came up about 2- 2 1/2"s. Didn't do anything to the rear because I liked the original height of the rear. Now the problem is the front end bounces up and down like one of those Hip-Hop cars!! what did I do wrong and how do I fix it? Do I need to back off the torsion bars or what?
Tighten the torsion bars until the AHC is in spec using tech stream.
 
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Give them about 5 to 8 turns on the adjustment bolt for the torsion bars. Might hit them with pbBlaster or wd first
 
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Where can I buy a text stream and is there a certain version that I need to buy? I guess you hook it up to your Lab top?
Yes, i got mine from ebay not sure on the version. For now i would do what Bill said turn them 5-10 times. Tighten it 5 rotations test drive and repeat until its better than do fine tuning with techstream.
 
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I need some help. I bought a LX470 and put an ARB combo bar on which is about 275lbs or so. I flushed out the AHC fluid using the @PADDO method. I shortened the front sensors all of the way but did not cut them and I moved the rear up all of the way. I added 30mm spacers to the rear. So far so good. When I hooked up tech stream, my initial front pressure was 11.0 and the rear was 7.8, whoa. So I gave the torsion bars 8 turns and got them down a few points each. So then I gave her 13 more turns each which bottomed the bolts out. The pressures are now 6.7 for the front and 6.3 for the rear. Am I ok now? Even with the bars cranked all of the way? Thank You
 
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I need some help. I bought a LX470 and put an ARB combo bar on which is about 275lbs or so. I flushed out the AHC fluid using the @PADDO method. I shortened the front sensors all of the way but did not cut them and I moved the rear up all of the way. I added 30mm spacers to the rear. So far so good. When I hooked up tech stream, my initial front pressure was 11.0 and the rear was 7.8, whoa. So I gave the torsion bars 8 turns and got them down a few points each. So then I gave her 13 more turns each which bottomed the bolts out. The pressures are now 6.7 for the front and 6.3 for the rear. Am I ok now? Even with the bars cranked all of the way? Thank You
Ya its fine from my understanding. If you need more torision you can reindex the torision bars.
 
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