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

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They are pretty tough to locate nowadays! I've been looking at these ones which say in the Description:
"LEXUS LX470 UZJ100R - 4WD 1998 - 2006"

And confusingly it differs from their "Compatibility" section, where 2007 and even 2008 is included. To try to get to the bottom of this discrepancy I've been back and forth messaging with the company, but the person I'm speaking with "confirmed" they don't have any King springs compatible with a 2007 AHC LX470.
 
gwrobertson89 said:
They are pretty tough to locate nowadays! I've been looking at these ones which say in the Description:
"LEXUS LX470 UZJ100R - 4WD 1998 - 2006"

And confusingly it differs from their "Compatibility" section, where 2007 and even 2008 is included. To try to get to the bottom of this discrepancy I've been back and forth messaging with the company, but the person I'm speaking with "confirmed" they don't have any King springs compatible with a 2007 AHC LX470.
Click to expand...
@bozncsurf @geo5 @GTV
gwrobertson89 said:
They are pretty tough to locate nowadays! I've been looking at these ones which say in the Description:
"LEXUS LX470 UZJ100R - 4WD 1998 - 2006"

And confusingly it differs from their "Compatibility" section, where 2007 and even 2008 is included. To try to get to the bottom of this discrepancy I've been back and forth messaging with the company, but the person I'm speaking with "confirmed" they don't have any King springs compatible with a 2007 AHC LX470.
Click to expand...
And actually King Springs seem to say the same on their website: LEXUS LX470 UZJ100R - 4WD 1998 - 2006 - Fit your Vehicle - King Springs Automotive Aftermarket Springs - https://kingsprings.com.au/catalogue/vehicle/526/lexus-lx470-uzj100r-4wd-1998-2006
 
Thanks @gwrobertson89 - this is interesting.

I am going to keep my kings on the truck, they seem to be working normally, will follow up if any issues.

Edit to add- I do not have extra AHC lift, system is working within factory parameters.
 
Thanks all! Some background context and additional updates - somebody from King Springworks got back to me confirming all I need to do is ensure the product code is KTRS-79 and they are compatible with the 2007 regardless of what the vendor is saying.

The context:
I've just added steel front & rear bumpers, and have a roof rack on the way. Call it 300 pounds of permanent extra weight. My next step will be to do the Techstream AHC diagnostics to see how things are looking pressure-wise. If they are high, I'll likely add King or LC springs and crank the torsion bar as necessary to get them to ideal levels. Will likely do the AHC speed sensor override switch (just so I can drive ever-so-slightly faster than 20mph on the beach in High).

Although I'd love to do some AHC lift work, I'm scared things could get messed up down there eventually and become very expensive to remediate. A valuable but overwhelming amount of info and perspectives in these threads about AHC lifts (e.g. sway-a-way bars / links / AHC shock spacers / rear dif drop / new torsion bars / spring spacers etc etc etc).
 
Finally got around to installing the Japan 4x4 spacers I have had sitting around for well over a year. Fabbed a rear bracket using 3/4in x 5in piece of aluminum. Now just need to cross level and check pressures on tech stream.

IMG_2404.webp
 
Just wanted to provide a reference point for anyone looking to do an AHC spacer lift in the future.

Checked my pressures and dialed in the front at 6.7 with a full tank. I might crank the t bars a little more to get to 6.5. Before the lift my rear pressure was always a little high at 6.6, but still within upper end of spec. After the lift I’m at 8.6 in the rear so am going to have to upgrade from the king springs to LC100 springs. I don’t think the 30mm space will bump me down enough to be in spec.

I’m running ADGU drawers that are usually mostly full, white knuckle dom sliders, dissent skids, dissent roof rack, and GFC RTT.

Globes are OEM and new. I replaced them in the last year. Fluid has been changed at least 3 times in the past 100k miles.

Fully loaded with camping gear, dogs, and two people I’m coming in at about 7,300 lbs.

If anyone has any other spring ideas let me know. I believe lx450 springs were an upgrade option, but they have been discontinued by Toyota.
 
DirtDawg said:


Well all my parts finally showed up and this past weekend I lifted my LX. My goal was to have a 2-2.5" lift (using the AHC system), while keeping close to stock travel characteristics and stock neutral pressures.

Components Installed:
KING KTRS-79 Coils (sourced from eBay seller sparesbox_auto)
AHC Shock Spacers (sourced here: AHC Spacers - Possible Group buy)
2 x front sway bar links
2 x rear sway bar links
2 x rear sway bar bushings

Front Spacer Install:
  1. Remove the wheel & tire
  2. Unbolt the sway-bar
  3. Unbolt the bottom bolt of the shock
  4. Using a pitman arm puller (or similar), detach the knuckle from the upper ball joint. This allows the lower control arm to droop low enough for you to insert the spacer.
  5. You need to drill a 1/2" hole to bolt the spacer to the lower shock mount. Bolt up the spacer through the bottom bolt so you can locate where to drill. I used a step-up bit and made quick work of it.
  6. Once the hole is drilled, go ahead and bolt it all up. Remember to use the included spacer on the lower bolt. (I had to shave quite a bit of material off of the spacer in order for it to fit.)
  7. Reassemble upper bj to knuckle and sway bar.
  8. Remount wheel & tire
  9. Your'e all set. Remember that this alone will not change the height of the vehicle. The AHC will just compress the shock further, so be sure to adjust the height sensor.


Front Sensor Modification:
  1. To lift the front of the vehicle you need to modify the linkages to the height sensor. The linkage is basically two 'ball joints' connected by a rod. One side is reverse thread. You need to shorten that rod in order to lift the vehicle.
  2. There are different methods to shorten the rod. You can simply just screw them all the way in, but this will only net about 1". The other option is to cut the rod shorter on both sides so the joints can be screwed all the way down, making it as short as possible. I did a mixture of the two and only cut the normal-thread side, then tightened down the joint on said side. The other side I simply just screwed down all the way. This netted me about 2.25" of lift in the front.


Rear Spring and Spacer Install:
  1. Jack up the rear of the vehicle and put jack stands under the vehicle. Remove tires & wheels from both sides.
  2. Unbolt the lower shock mounts and the sway bar. Disconnect both. I also disconnected the linkage to my rear height sensor at the time as to not damage it.
  3. Go ahead and flex the axle to replace the coils. I found that a jack under one side of the axle and a friend pushing down on the other, practically causes the coil to fall out. Swap out each side that way.
  4. The rear shock spacer is simple, just droop the axle lower than the bottom eyelet of the shock (enough to fit the spacer in), rotate the eyelet 90*, and bolt up the rear spacer.
  5. Bolt back up the sway bar and remount the wheels and tires. Lower vehicle.



Rear Sensor Modification:
  1. Two methods of adjustment here, first, you can move the linkage all the way up on the adjustment slot, but this only netted me about 1". To go higher, you need to make a bracket that moves the linkage up higher. I simply used a 1" x 6" strip of sheet metal with holes and an adjustment slot drilled in it.


Correcting Neutral Pressures:
  1. First I started up tech stream and got my baseline pressures (going from L to N). First pressures read front: 8.3 / rear: 7.1. This was after coming from stock height with pressure in spec. I also lowered the rear by 1/2" after this reading because it was a little too high for my satisfaction. We're looking for front: 6.9 +/- 0.5 and rear: 5.6-6.7
  2. I cranked the T-bars 2 turns, drove around the block and booted back up tech stream. Front: 7.9 / rear: 6.7
  3. 3 more turns, front: 7.1 / rear: 6.5
  4. 1 1/2 turns, front: 6.9 / rear: 6.5 (now were getting somewhere) I decided that on a worn out system I would want to get my front pressures just a little lower.
  5. 1 1/2 more turns and were at front: 6.5 / rear: 6.5
Make sure to get an alignment after changing the front height of your LX

Before:


After:


So in the end I still have full range of my AHC shocks, no bottoming out, while maintaining stock pressures. As for ride quality, I would say that it is just a comfortable as before, but with a firmer ride. The front is just as cushy, while the back is firmer, but still handles the bumps well. I think next weekend I am going to reinstall my rear 30mm spacers to see if I can lower my rear pressure to a good level. I believe the king springs may work better with a lower pressure. I gained 2.25" in the front and 2.5" in the rear. No issues with vibrations or anything else. The spacers will creak a little at first 'til they settle in. Also my CVs are slinging grease due to the change in angle, but I have a reboot sitting in the garage for another day.

Click to expand...
Are these spacers still available somewhere? I’ve got an 07 LC with AHC that’d I’d like to do this to
 
Sargy said:
Im having great results using Dobinson springs (C59-221V, originally for 80 series). This is with sensors maxed out on their original bracket. Helm joints up front were not shortened. Neutral pressure out back were about 6.0 give or take. Initial reactions showed that I had fairly strong rebound, without a lot of bounce. After a few days of settling this improved. Stopped by Lowes to buy 210lbs worth of Sand tube bags and the ride now better than stock. Rear also has 295/70/18 spare and 3rd row, dissent bumper coming soon View attachment 1857123 View attachment 1857142 View attachment 1857141 Again, the ride is much more compliant now with a lot more control with the stiffer spring after about 1k miles of driving. Rides like a dream with firmer bumps, nothing jarring. You guys with more lift could benefit with this setup, without the sandbags and more weight capacity;).

I took a leap of faith with this one.
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Sargy, I know this is an old post, but I'm getting ready to order the dobinsons c59-221v after hearing about your experience. I'm wondering how this has held up long-term and if there's anything else I should know? Also, are you still able to use all AHC positions? I have a heavy rig for my family of 4 and king springs haven't been enough. Fully loaded it either stuck in N and won't go into H or sensor is reading L when in N.
 
AhopX said:
Sargy, I know this is an old post, but I'm getting ready to order the dobinsons c59-221v after hearing about your experience. I'm wondering how this has held up long-term and if there's anything else I should know? Also, are you still able to use all AHC positions? I have a heavy rig for my family of 4 and king springs haven't been enough. Fully loaded it either stuck in N and won't go into H or sensor is reading L when in N.
Click to expand...
What are your pressures now in the rear? I had to add spacers to my kings to make them work. But I wasn’t experiencing any symptoms like you are just high numbers.
 
Hello Forum,
I'm the mechanic working with AhopX on his 2003 LX470...

AhopX's LX is outfitted for adventure / overlanding 24/7. None of the items below are removed on a regular basis.
Substantial weight has been added, primarily to the rear:
- Hitch-mounted Swing-out Spare Tire Carrier w/ Full Size Wheel & Tire
- Dometic Fridge on Slide-out where passenger 3rd row seat would be
- Kitchen Module (soon to be on Slide-out...) where driver 3rd row seat would be
- Lithium Battery Module and Tools beside Kitchen Module
- iKamper Hard Shell RTT
- iKamper Awning
- etc.

In addition, he's got a Spare Tire Area Water Tank.
Not usually filled, but needs to be accounted for...

AhopX's LX does Not have a Sensor Lift.
Front and Rear Sensors are at Stock Height.

We installed the AHC King Springs about 3 months ago and got the AHC Pressures in spec (Front was 6.9, Rear was 5.3).
This was prior to the Hitch-mounted Swing-out Spare Tire Carrier and some of the extras in the 3rd Row Seat area.
On his last road trip (Pittsburgh to Burning Man and other areas West...), the LX470 had issues going into H, and sometimes maintaining N, when fully loaded (Wife, 2 Small Kids, Food, Clothing, Full Water Tank).

After returning, we checked the AHC Pressures in its new "Normal" state.
Front 7.1, Rear 8.2.
Rear way too high...

Adding Rear Coil Spring Spacers would not make enough difference.
Time for Heavier Rear Springs.

After multiple discussions, we decided to order / install Dobinson's C59-221V Rear Coil Springs.
These are typically used on 80 and 100 Series Land Cruiser / Lexus LX with Stock Height and Stock Weight without AHC.

We installed the New Dobinson's Coil Springs and also Replaced the Rear Sway Bar Bushings / Hardware.
Then took it for a 15 minute / 5 mile drive.
Less Wallow / Roll. More Stable.
Rides pretty much the same as my 2003 LX does with King Springs and 6 Adults.

After Test Drive, Post Install Pressures were Front 7.3, Rear 5.6.
After adjusting Front Torsion Bars, Front 6.9, Rear 5.6.

Front is "Perfect", which is to be expected after adjusting Torsion Bars.
Rear is at the Low End of the Acceptable Range (5.6 to 6.7).
This is where we were hoping to be, to give us more capability to add water to the Spare Tire Area Tank for extended periods of time.

IMO, these Springs are a Good Option for AHC LCs / LCs with a bunch of weight in the Rear.
They are around $300 + Tax with Free Shipping.
Note: They are Progressive / Variable Rate Springs, which should give additional protection / support for additional temporary weight in the rear.

Enjoy.
Tom
 
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