AHC issue after installing rear springs. (OME 2865s)

[LBCLX470]

Hi all! I have a noob question for the LX470 guys. Before I start I would like to say that I signed up on MUD about 2 years ago, but have been trolling it for more than 5 years after I got my hands on a pristine 1999 LX470 with 120K on it. (wife worked at a car dealership and it was a trade-in). I can’t say I’m mechanically inclined, but I do oil , brake pad replacements, spark plug and coolant changes on 4 of my cars.

So now to my question. I recently bought OME 2865s from a member here to compensate the weight shift when I installed a rear bumper with a tire swing out. The suspension was stock and I had no issues with it. I didn’t have any problem installing 2865s, but I did notice significant change in height in the rear. I got an extra 1.5” lift in the rear. When I attempted to lower the AHC from normal to low, only the front lowers and maybe barely in the back. When I test drove it, it feels like a pogo stick over bumps and no dampening from the shock. I do get some dampening from the shock when it’s on the “H” position.

FYI: I did measure the fluid on the low, normal, and high positions before the install and it’s normal. (7 marks from low to high).



Thanks in Advance! - Ed

 

[bamabrock]

You put way too high of a spring rate for a working AHC suspension. Put the stock springs back on.

 

[LBCLX470]

You put way too high of a spring rate for a working AHC suspension. Put the stock springs back on.

Thanks for the quick reply. I'll put on the old ones after work! Are there any aftermarket springs that will work with AHC?

 

[NKP Garage]

Only way you can really use springs that tall and keep AHC happy is to raise the shock mounts so that they operate at normal extension that the AHC expects.

 

[jLB]

Are there any aftermarket springs that will work with AHC?

King Springs makes some

KING KTRS-79

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

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)...

forum.ih8mud.com

 

[LBCLX470]

I got excited and didn't do any in-depth research. I want to keep the AHC capability. @jLB - ill look into this thanks!

 

[LBCLX470]

I was looking at another thread and it seems like the stock LC100 rear springs may work.

 

[NKP Garage]

I was looking at another thread and it seems like the stock LC100 rear springs may work.

They will. That's what I did on my old LX470, but you still need shock spacers to keep AHC happy and working correctly.

 

[GTV]

The stock LC springs might work, it's worth a try since they're usually available cheap second hand. It will also depend on weight and what height you want to end up at. It will probably take some trial and error to get where you want.

 

[NKP Garage]

I don't remember which shock extension brackets I used on my LX470. I remember I had to buy a few pairs until I found one that fit. Here are a few examples:

https://amzn.to/3Lb0hMz

https://amzn.to/3oaJxuD

 

[ChaoticSquare]

Even the kings will be bouncy if you have no additional weight. Mine is bouncy as I don’t have my drawer system in yet, but am planning to hence the kings.

 

[peacesells63]

I have a pretty new set of oem springs for sale if you decide to go that route

 

[Tres Toys]

Some things to consider are how much extra weight you carry around, how often you carry that weight and what kind of ride quality you desire loaded and unloaded.
Two other reasonable priced options you might consider:
1. Use a spring spacers with your stock coils (This may be able to compensate enough for your rear bumper if you springs are not to worn out)
2. Add a set of air bags to the coils(Can compensate for bumper and adjusted for carrying heavier loads.)
There are a couple threads on these if you do some searching.
Best of luck.

 

[codertimt]

Rears from an 80 are another option. They are a bit lighter than stock non-AHC 100 springs from what I remember. That what I've been running for the past 70K miles or so. Rear 4x4 labs, homemade drawer, and fridge in the rear full time.

You definitely want to research AHC pressure and techstream on here though. Also AHC height sensors and how they interact with the suspension. A bit of reading and a couple of ebay purchases and you should find yourself in control of the situation...

 

[LBCLX470]

Thank you for all the great advice and suggestions . I had plans to put the stock rear springs after work today, but ran out day light. Once the stock springs are installed, I’m gonna sit back and reflect on my next move. I just received my AHC fluid from the mail so I was planning to drain and flush the system after the spring swap. The only place I could find the fluid was on eBay and I paid an arm and a leg for it! No Lexus or Toyota dealership had it.

 

[LBCLX470]

I don't remember which shock extension brackets I used on my LX470. I remember I had to buy a few pairs until I found one that fit. Here are a few examples:

https://amzn.to/3Lb0hMz

https://amzn.to/3oaJxuD

Wait…what are those for?

 

[LBCLX470]

Rears from an 80 are another option. They are a bit lighter than stock non-AHC 100 springs from what I remember. That what I've been running for the past 70K miles or so. Rear 4x4 labs, homemade drawer, and fridge in the rear full time.

You definitely want to research AHC pressure and techstream on here though. Also AHC height sensors and how they interact with the suspension. A bit of reading and a couple of ebay purchases and you should find yourself in control of the situation...

Thanks I will. I definitely need to read more about the AHC if want to keep it.

 

[jLB]

The only place I could find the fluid was on eBay and I paid an arm and a leg for it! No Lexus or Toyota dealership had it.

Before you start your AHC fluid swap, make sure that you’ve looked through one or more of the threads that seem to explain why it’s hard to find at a dealership right now.

AHC Fluid flush gone wrong...

Hey Guys, Just bought a 2000 LX470 with 263K miles and wanted to baseline all the fluids. I picked up some AHC fluid from two different Toyota dealerships (Magnusson's in Palo Alto, and Capitol Toyota - CA San Jose) as it was really hard to find. I did the flush following PADDO's method along...

forum.ih8mud.com

AHC Help: Can't clear code

Hey fam! I just replaced my AHC globes and while bleeding and refilling the system after, the AHC threw a code 62/1762 Abnormal pump pressure. I apparently got a contaminated bottle of AHC fluid which contained a white gel (from the dealer)! I didn't notice until I started to add more and saw...

forum.ih8mud.com

 

[LBCLX470]

Even the kings will be bouncy if you have no additional weight. Mine is bouncy as I don’t have my drawer system in yet, but am planning to hence the kings.

I was thinking of a drawer system myself, but not for awhile.

 

[LBCLX470]

Before you start your AHC fluid swap, make sure that you’ve looked through one or more of the threads that seem to explain why it’s hard to find at a dealership right now.

AHC Fluid flush gone wrong...

Hey Guys, Just bought a 2000 LX470 with 263K miles and wanted to baseline all the fluids. I picked up some AHC fluid from two different Toyota dealerships (Magnusson's in Palo Alto, and Capitol Toyota - CA San Jose) as it was really hard to find. I did the flush following PADDO's method along...

forum.ih8mud.com

AHC Help: Can't clear code

Hey fam! I just replaced my AHC globes and while bleeding and refilling the system after, the AHC threw a code 62/1762 Abnormal pump pressure. I apparently got a contaminated bottle of AHC fluid which contained a white gel (from the dealer)! I didn't notice until I started to add more and saw...

forum.ih8mud.com

Before you start your AHC fluid swap, make sure that you’ve looked through one or more of the threads that seem to explain why it’s hard to find at a dealership right now.

AHC Fluid flush gone wrong...

Hey Guys, Just bought a 2000 LX470 with 263K miles and wanted to baseline all the fluids. I picked up some AHC fluid from two different Toyota dealerships (Magnusson's in Palo Alto, and Capitol Toyota - CA San Jose) as it was really hard to find. I did the flush following PADDO's method along...

forum.ih8mud.com

AHC Help: Can't clear code

Hey fam! I just replaced my AHC globes and while bleeding and refilling the system after, the AHC threw a code 62/1762 Abnormal pump pressure. I apparently got a contaminated bottle of AHC fluid which contained a white gel (from the dealer)! I didn't notice until I started to add more and saw...

forum.ih8mud.com

Yep from what I read it’s proprietary to Toyota only and it’s not just any regular hydraulic oil and very different from dextron vi