2-2.5" AHC Lift Using King Coils & Shock Spacers

[Joe Bob]

Following. Great info here to someone like me who is new to AHC!
Planning to give my 2006LX a mild 1.5”-2” lift to fit in 275/70R18 BFG KO2s.

Like what others have mentioned, I love how the versatile the AHC is, my kids and wife love the cushy ride. We all agreed that it sits a little low compared to the previous trucks we’ve owned so I have to do a mild lift to it.

I have a few questions for those who have done this mod:
- So for me to lift my LX 1.5” - 2” (max), is it really necessary to install the front and rear lower shock mount steel spacers (or replace rear coil springs to KINGS)?
- Let's say I just want to level the front with the rear, will adjusting the heim/sensor at the front do it? (it currently looks like it's kneeling or stooped down in the front - sorry I am not familiar yet with the terms I have no idea what's it called).

View attachment 2025939

**Current setup:
- stock tires
- stock torsion bars
- 100 miles on to the new AHC fluid
- cranked the driver and passenger side torsion bars 4 1/2 turns yielded to 3/4" lift at the front (which I think was still not enough to level the front to the rear)
- i have no techstream to read pressures of the front and rear globes

Thanks in advance gents.

You need techstream. If you crank torsion bars you can bet your specs are off. Also, no need to lift with the tires you are adding. I run the same with no issues. I get my lift when I need it by pressing, "high." I added king springs for the added weight of swing out bumper and towing a UEV 490

 

[FLtrails]

Following. Great info here to someone like me who is new to AHC!
Planning to give my 2006LX a mild 1.5”-2” lift to fit in 275/70R18 BFG KO2s.

Like what others have mentioned, I love how the versatile the AHC is, my kids and wife love the cushy ride. We all agreed that it sits a little low compared to the previous trucks we’ve owned so I have to do a mild lift to it.

I have a few questions for those who have done this mod:
- So for me to lift my LX 1.5” - 2” (max), is it really necessary to install the front and rear lower shock mount steel spacers (or replace rear coil springs to KINGS)?
- Let's say I just want to level the front with the rear, will adjusting the heim/sensor at the front do it? (it currently looks like it's kneeling or stooped down in the front - sorry I am not familiar yet with the terms I have no idea what's it called).

View attachment 2025939

**Current setup:
- stock tires
- stock torsion bars
- 100 miles on to the new AHC fluid
- cranked the driver and passenger side torsion bars 4 1/2 turns yielded to 3/4" lift at the front
- i have no techstream to read pressures of the front and rear globes

Thanks in advance gents.

 

[bamabrock]

Planning to give my 2006LX a mild 1.5”-2” lift to fit in 275/70R18 BFG KO2s.

- Let's say I just want to level the front with the rear, will adjusting the heim/sensor at the front do it? (it currently looks like it's kneeling or stooped down in the front - sorry I am not familiar yet with the terms I have no idea what's it called).

- cranked the driver and passenger side torsion bars 4 1/2 turns yielded to 3/4" lift at the front (which I think was still not enough to level the front to the rear)

You dont need a lift to run those tires. I posted pics of my 100 in this thread.

2-2.5" AHC Lift Using King Coils & Shock Spacers

Awesome - thanks Dawg & Hoser. Exactly the info I was looking for. Any idea about availability of those spacers? Is the guy in Japan still around?

forum.ih8mud.com

You cant "level" a AHC vehicle. It is designed to have a 3/4" of rake. Don't crank on the torsion bars because you are not lifting the front up in an AHC equipped vehicle like it would with a regular torsion bar equipped vehicle , but rather changed the pressures from the added spring rate you're adding and the system will adjust back to set rake.

Read this thread twice before touching the system.
Definitive list of AHC maintenance items

Then install techstream and properly setup your AHC:

How-To: TechStream In 5 Minutes

forum.ih8mud.com

 

[FLtrails]

I was about to say the same thing. Those are 33” tires slightly bigger than 285 65 18 that everyone runs with no lift. Search this forum to try to find a link where someone has successfully run techstream lately. It’s only like $30 on eBay with the cable. But many versions only run on an old XP windows computer. It’s a hassle to get it to work on a modern laptop. But it’s worth it. Otherwise you’re totally in the dark.
Cranking bars alone caused a 3/4” lift in front??? That shouldn’t happen as the height sensor should drop the pressure in the system to keep it the same height. Unless it’s so cranked it’s more than it can account for. Techstream will tell you. I’m not the expert on that hopefully someone will chime in on this lift issue.

 

[krispykritter]

Going to pretty much echo everyone else. I run 275/70r18's (roughly a 33) and they fit with zero rubbing before the lift. You can even put a 33 in the spare tire spot without rubbing anything.

You can lift it on AHC alone with either an AHC override switch (to stay in high permanently) or by adjusting all of your height sensors to provide more height via the AHC system in normal mode. I don't like either of these options because they result in higher pressures in your AHC system - higher pressure can mean earlier failure. The beauty of the AHC lift is you gain height while returning the struts to their normal ride length, then you adjust your AHC pressures to be in-spec via the t-bars and king springs.

Cranking the t-bars should not net you any height gain alone - the system sets the ride height via AHC height sensor readings and pressure. More T-bar pressure means less AHC pressure for the same height sensor reading. The right method to gain height with our suspension system is to adjust the height sensors (there's on in each front wheel well, and a single one for the rear axle kinda middle of the truck), then crank the t-bars to get the AHC pressure back in spec.

You NEED techstream and a mini VCI cable to do this correctly. Without seeing your AHC pressures and sensor height readings, you're just screwing around and likely screwing it up. I would not agree that you can't level an AHC vehicle - you certainly can, it just takes a bit more work than simply cranking the t-bars. There's an actual tutorial on how to do this somewhere, but for your case where you just want to lift the front a bit, you would:

1. Hook up techstream/mvci - go to AHC data
2. Adjust height sensors to increase standing height - be careful doing this! The vehicle can realtime adjust it's height under certain conditions. If you keep the door open, AHC shouldn't kick in while you adjust the sensors, but should adjust when you shut the door. Keep adjusting the sensors until you get the ride height you want.
3. Crank the front t-bars in until the front AHC pressure is back in spec. Equal number of cranks per side. In order to see AHC pressures update on Techstream, you have to put the vehicle in low, then back to normal, and let it get happy. Whatever the last reading was will persist. If it's out of spec, go do some more cranking, then check again using the low/normal thing.

In order to lift the rear and get the pressures in spec, you have to either add in spring spacers or new springs - spacers just lift it, new springs lift it and give you a bit more load capacity/handling.

 

[OEMGUY0720]

Going to pretty much echo everyone else. I run 275/70r18's (roughly a 33) and they fit with zero rubbing before the lift. You can even put a 33 in the spare tire spot without rubbing anything.

You can lift it on AHC alone with either an AHC override switch (to stay in high permanently) or by adjusting all of your height sensors to provide more height via the AHC system in normal mode. I don't like either of these options because they result in higher pressures in your AHC system - higher pressure can mean earlier failure. The beauty of the AHC lift is you gain height while returning the struts to their normal ride length, then you adjust your AHC pressures to be in-spec via the t-bars and king springs.

Cranking the t-bars should not net you any height gain alone - the system sets the ride height via AHC height sensor readings and pressure. More T-bar pressure means less AHC pressure for the same height sensor reading. The right method to gain height with our suspension system is to adjust the height sensors (there's on in each front wheel well, and a single one for the rear axle kinda middle of the truck), then crank the t-bars to get the AHC pressure back in spec.

You NEED techstream and a mini VCI cable to do this correctly. Without seeing your AHC pressures and sensor height readings, you're just screwing around and likely screwing it up. I would not agree that you can't level an AHC vehicle - you certainly can, it just takes a bit more work than simply cranking the t-bars. There's an actual tutorial on how to do this somewhere, but for your case where you just want to lift the front a bit, you would:

1. Hook up techstream/mvci - go to AHC data
2. Adjust height sensors to increase standing height - be careful doing this! The vehicle can realtime adjust it's height under certain conditions. If you keep the door open, AHC shouldn't kick in while you adjust the sensors, but should adjust when you shut the door. Keep adjusting the sensors until you get the ride height you want.
3. Crank the front t-bars in until the front AHC pressure is back in spec. Equal number of cranks per side. In order to see AHC pressures update on Techstream, you have to put the vehicle in low, then back to normal, and let it get happy. Whatever the last reading was will persist. If it's out of spec, go do some more cranking, then check again using the low/normal thing.

In order to lift the rear and get the pressures in spec, you have to either add in spring spacers or new springs - spacers just lift it, new springs lift it and give you a bit more load capacity/handling.

Thanks for the detailed walkthrough @krispykritter . Seems like the first step is really to get one of those techstreams which I will order today.

Next is to return the original settings of the torsion bar. Jacked it up, cranked the torsion bars, put it down, measured 3/4” increase and went to bed, thought that was it. Had other trucks before that also runs on torsion bars and that’s how we do it. Just realized now AHC doesn’t work that way. I just measured it now returning home and you are all correct, it indeed readjusted back to it’s original height (basing in on “N” mode).

Yes I read the 275/70R18 would fit an AHC equipped LX470 and there will be no rubbing, but I really want to level the front and make it look like a truck instead of a race car.

The AHC feature is a hit with the grandparents, making it easier for them to board. So I really intend to keep this system for as long possible - just want to make a few little adjustments here and there for both aesthetic and performance purposes.

I also read about the override switch - I don’t think I’ll do that as I have experienced driving this on L or H even on low speed and the ride is just way too stiff, so crossing that out on the list.

 

[OEMGUY0720]

You dont need a lift to run those tires. I posted pics of my 100 in this thread.

2-2.5" AHC Lift Using King Coils & Shock Spacers

Awesome - thanks Dawg & Hoser. Exactly the info I was looking for. Any idea about availability of those spacers? Is the guy in Japan still around?

forum.ih8mud.com

You cant "level" a AHC vehicle. It is designed to have a 3/4" of rake. Don't crank on the torsion bars because you are not lifting the front up in an AHC equipped vehicle like it would with a regular torsion bar equipped vehicle , but rather changed the pressures from the added spring rate you're adding and the system will adjust back to set rake.

Read this thread twice before touching the system.
Definitive list of AHC maintenance items

Then install techstream and properly setup your AHC:

How-To: TechStream In 5 Minutes

forum.ih8mud.com

Thanks @bamabrock I will certainly read this tonight and will report back or post my inquiries here.

 

[krispykritter]

No problem - I also want to keep AHC as long as possible because it's such a nice feature.

I know I got the techstream program off some dodgy ass download site, and the mvci cable I bought off of Amazon. I can try and find you a link if you want... It came with the program but I didn't try to install it since I already had a working version.

The real techstream is a dealer tool and costs a ton of money. You're looking for the hacked version. Plenty of info via search and/or Google, make sure you read a fair bit before buying anything!

 

[OEMGUY0720]

You need techstream. If you crank torsion bars you can bet your specs are off. Also, no need to lift with the tires you are adding. I run the same with no issues. I get my lift when I need it by pressing, "high." I added king springs for the added weight of swing out bumper and towing a UEV 490

Got it thanks @Joe Bob . When you replaced your rear coilsprings to king springs, did you adjust your rear AHC pressures using techstream? And the king springs you put on is it to increase rear loading capacity AND lift it 2-inches? Or, it’s still stock height but loading capacity is now increased?

 

[menancyandsam]

Got it thanks @Joe Bob . When you replaced your rear coilsprings to king springs, did you adjust your rear AHC pressures using techstream? And the king springs you put on is it to increase rear loading capacity AND lift it 2-inches? Or, it’s still stock height but loading capacity is now increased?

Remember the only way to get lift is by raising the height of the sensor.
King springs help with loading capacity.

 

[krispykritter]

Got it thanks @Joe Bob . When you replaced your rear coilsprings to king springs, did you adjust your rear AHC pressures using techstream? And the king springs you put on is it to increase rear loading capacity AND lift it 2-inches? Or, it’s still stock height but loading capacity is now increased?

Remember the only way to get lift is by raising the height of the sensor.
King springs help with loading capacity.

If you just add king springs without adjusting the sensors, you end up with really low rear AHC pressures - in the 2.5-3 MPa range. Spec is something like 5.6 MPa. The kings net you both lift at stock pressures (after a sensor adjustment) and increased load capacity (kings are 130 lbs/in vs OE at 90 lbs/in). You can just get increased load capacity by not adjusting the AHC sensors, but your shock dampening mostly goes away because the rear system pressure is too low to effectively damp the springs.

 

[OEMGUY0720]

Been reading the posts back and forth see if I missed anything as well as the links you all posted as reference. Learning a lot about this complex truck. Really want now to adjust the heim height sensor and lift the front a little bit and level it with the rear (in preparation for the 275/70R18 + 1.25” wheel spacers on all 4 wheels) even w/o the techstream. But like what you all said we don’t want to do that as it will mess ul the AHC system. I have yet to figure out how to download and install the “techstream” on my windows 8 laptop also to get one of those miniVCI cable things.

 

[Joe Bob]

My pressures in the rear were high. My rig is primarily for overland use. I have full gobi rr, dissent rear bumper with swingout, rock sliders, full tool kit and recovery gear including 60 inch highlift. Plus, I tow a 4k lbs trailer, I carry 2 adults, 2 kids, and 2 dogs. I have no need for a lift when freeway driving, it's better to keep center of gravity low. If I need clearance when on the trail I just hit high mode. My ahc specs are dialed, but I have cranked the torsion bars since I am so heavy.
To me lift is only necessary to fit tires or to look pretty! Lol
I'd recommend getting king springs only if your techstream says you need to.
Here's a pics of my ride doing some fun technical trails with only ahc as on demand lift.

 

[Joe Bob]

Following. Great info here to someone like me who is new to AHC!
Planning to give my 2006LX a mild 1.5”-2” lift to fit in 275/70R18 BFG KO2s.

Like what others have mentioned, I love how the versatile the AHC is, my kids and wife love the cushy ride. We all agreed that it sits a little low compared to the previous trucks we’ve owned so I have to do a mild lift to it.

I have a few questions for those who have done this mod:
- So for me to lift my LX 1.5” - 2” (max), is it really necessary to install the front and rear lower shock mount steel spacers (or replace rear coil springs to KINGS)?
- Let's say I just want to level the front with the rear, will adjusting the heim/sensor at the front do it? (it currently looks like it's kneeling or stooped down in the front - sorry I am not familiar yet with the terms I have no idea what's it called).

View attachment 2025939

**Current setup:
- stock tires
- stock torsion bars
- 100 miles on to the new AHC fluid
- cranked the driver and passenger side torsion bars 4 1/2 turns yielded to 3/4" lift at the front (which I think was still not enough to level the front to the rear)
- i have no techstream to read pressures of the front and rear globes

Thanks in advance gents.

Oh... I'd yank off those side steps too... that will give you a 3 inch lift! At least for your rockers!

 

[ChuckB]

I'm a little late to the party, but will add another data point on no lift needed for those tires. Also running non-OEM spheres/globes and new OEM-AHC springs and 30mm Slee spacers in the rear for cargo capacity, not lift as mentioned.

Wanted to re-emphasize the importance of this thread Definitive list of AHC maintenance items

 

[krispykritter]

Here's the amazon link to the cable I ordered a while back. I used it with techstream to check my pressures during my lift. No idea if the techstream provided with it works, but the cable worked fine for me.

Amazon Link

 

[CanadianRockyCruiser]

I recently put King Springs KTRS 79's on my 2001 LX470. I have:

-Front ARB Sahara bumper with 12,500lb winch
-Cruisin' Offroad Sliders
-Dissent "no-cut" rear bumper with one tire swing out
-about 200lbs of recovery, camping, and other gear
-Front Runner Slimline roof rack

Before installing the King Springs, my pressures were at 7.8 front and 7.2 rear. After installing the King Springs, my pressures are at 6.5 front and 6.2 rear. I'll probabaly adjust the torsion bars to get to 6.7 on the fronts and see if that pulls down the rear a bit.

I still haven't installed the Japan 4x4 shock spacers that I have, but that will probably be my next step.

 

[krispykritter]

I recently put King Springs KTRS 79's on my 2001 LX470. I have:

-Front ARB Sahara bumper with 12,500lb winch
-Cruisin' Offroad Sliders
-Dissent "no-cut" rear bumper with one tire swing out
-about 200lbs of recovery, camping, and other gear
-Front Runner Slimline roof rack

Before installing the King Springs, my pressures were at 7.8 front and 7.2 rear. After installing the King Springs, my pressures are at 6.5 front and 6.2 rear. I'll probabaly adjust the torsion bars to get to 6.7 on the fronts and see if that pulls down the rear a bit.

I still haven't installed the Japan 4x4 shock spacers that I have, but that will probably be my next step.

Realistically, if your ride height isn't increased over stock (And I wouldn't think it would be with your weight load and pressures), there's no point to adding the japan4x4 spacers unless you want more wheel travel. I added them to let me lift the 100 and maintain stock pressure and ride, but now the limit to suspension travel is when things contact the shock body. Not ideal. I THINK aftermarket front control arms will fix that in front, but no idea what I can do with the rear besides limit straps.

 

[CanadianRockyCruiser]

Realistically, if your ride height isn't increased over stock (And I wouldn't think it would be with your weight load and pressures), there's no point to adding the japan4x4 spacers unless you want more wheel travel. I added them to let me lift the 100 and maintain stock pressure and ride, but now the limit to suspension travel is when things contact the shock body. Not ideal. I THINK aftermarket front control arms will fix that in front, but no idea what I can do with the rear besides limit straps.

Right... I'm considering adding them for a bit more lift.

 

[FLtrails]

You’ve got close to 200lbs of extra weight on the front bumper with the bumper itself and the huge winch. The sliders and roof rack will add a little more weight to the front as you’ll see half the weight distributed there. You said you then had front pressures of 7.8 with (I assume) stock adjustment of the front torsion bar. Makes sense with all that weight on the front. But to fix it all you did is stiffen the rear springs??? That brought your front pressure below spec so now you’ll make it looser than factory settings??? I’ll be trying this soon and am worried the factory front torsion bars won’t handle it. Did I misunderstand what you’ve done?