How do I get my 01 LX470 back to stock height?

[fanboy]

Hi,

Longtime reader, first-time poster.

I just bought a 2001 LX470. Seller is not a car person and isn't the first owner, and he doesn't know why the rear rides so much higher than the front (see front). I guess someone replaced the rear air suspension with lift-kit rear springs, but didn't bother to lift the front.

The only coil springs I see available for the rear are the Old Man Emus that promise 2" of lift. I don't want any lift. I just want stock. Are there other springs to use? Or am I overlooking something?

I'm also going to have my mechanic see how much of the air suspension system is still there. I wouldn't be against restoring the air suspension.

Warm greetings to all. And sorry about the bad angles in the attached photos.

 

[Trunk Monkey]

If you take some photos of the actual suspension people can give you a much better idea of what you've got.

 

[ramangain]

It isn't air suspension, it is hydraulic.

Try and diagnose your rear height control sensor.

 

[fanboy]

Yup. I just bought it. Will get suspension pics once it goes to the mechanic's. Thanks.

 

[medtro]

Use stock springs to get stock height. BTW, surprised to see questions like these from longtime reader.

 

[fanboy]

I was under the impression that there's no such thing as stock springs, since the stock suspension is hydraulic?

Sorry, no familiarity with these suspensions. Coming from the Range Rover world, where air suspensions can be replaced with aftermarket coils.

 

[ramangain]

Coming from the Range Rover world, where air suspensions can be replaced with aftermarket coils.

You're in for a shock - reliability!

 

[2001LC]

Replacing rear coil springs with OEM Toyota and than servicing AHC systems is how. The Coils don't have to be replaced, but usually a good idea with age. They're much lighter rear coils spring than non AHC, so don't last as long typically.

Testing, Servicing AHC and Fine tuning AHC height sensors (adjustors) for height, than front Torsion bars adjusting for side to side leveling and pressure setting is finally step. Even if aftermarket coils installed.

I'm going to tweek Emeralds AHC height adjuster today along with torsion bars. I did the coils already

 

[fanboy]

Huge thanks. Now I know what to look for. I actually have Techstream, so I'll fire it up when I have a chance and try to diagnose the suspension.

Yeah, Range Rovers are hilarious fun. They can actually be reliable if you replace every single thing in advance. Every car is a project car, basically.

I've had a Lexus LS400 for almost two decades now, so I definitely know the diference in reliability. In fact, I've been shopping for an LX470 for much of that time, but never found a decent cheap one until now.

 

[aging fleet]

Lets back up a bit. The AHC system employs both hydraulic shocks and coil springs in the rear and torsion bars up front. Because the hydraulic shocks handle more of the load, the torsion bar and spring rates are different between AHC and non-AHC 100s. That's just an FYI in case you decide to scrap the system.

About the current stance, as @ramangain mentioned earlier, you likely still have the AHC system installed but a rear height sensor may be bad.

 

[fanboy]

Thanks very much.

 

[fanboy]

I pulled out the Autel DS708. It had two AHC codes: pressure sensor circuit and abnormal pressure. I cleared the codes and in a few minutes of driving back and forth in my driveway, the codes didn't come back. Also, it seems the sensors know the rear is high, but they can't lower it? Sensor readings (after codes cleared) also attached. Visual appearance same as before. Previous owner did basically no maintenance, so I'm guessing there's no hydraulic fluid in it (but would that cause a too high condition, rather than too low? or is that a clever safety feature?).

Thanks for stopping me from buying new coil springs.

 

[ramangain]

1. How much fluid is in the reservoir? Another pic please
2. Are there any non-connected electrical connectors to the AHC system under the hood?
3. There is a reset procedure to jumper some specific pins to reset the AHC system. Hopefully someone can chime in on this, I don't recall right now. Try and perform it.
4. When the rig is running, all doors are closed, and windows down, when you hit the up arrow on the AHC switch, do you hear the AHC pump and motor running?

My general suggestion is to ensure the AHC stuff under the hood is working properly 1st. You can play with AHC sensor heights and tbars until the day you die, but the if the pump portion isn't working, then it is all a waste of time.

Don't get me wrong, you have some diagnosis and work to do to get it running and set properly. Hopefully mostly labor and fiddling and not too much money in parts.

 

[2001LC]

I pulled out the Autel DS708. It had two AHC codes: pressure sensor circuit and abnormal pressure. I cleared the codes and in a few minutes of driving back and forth in my driveway, the codes didn't come back. Also, it seems the sensors know the rear is high, but they can't lower it? Sensor readings (after codes cleared) also attached. Visual appearance same as before. Previous owner did basically no maintenance, so I'm guessing there's no hydraulic fluid in it (but would that cause a too high condition, rather than too low? or is that a clever safety feature?).

Thanks for stopping me from buying new coil springs.

View attachment 2462103

View attachment 2462104

To get Mpa readings. Lower vehicle (AHC "L") with tech stream hooked up. The raise to "N".

 

[fanboy]

Is this disconnected thing related to AHC? Thank you.

 

[2001LC]

That is hydraulic line of AHC, that attaches to top of frt RH shock. You'll find one at top of each of the 4 shocks.

 

[fanboy]

Photos and a video here:

2001 LX470 · Shared album ð¸

Tap to view!

photos.app.goo.gl

I'd greatly appreciate some advice whether it would be easier and cheaper to restore AHC functionality or just to buy non-AHC parts (and if so, what parts). All else equal, I'd like to have the AHC, but am not willing to pay much of a cost premium for it. Many thanks for advice.

 

[Sherlocker]

Cruiser parts has OEM shocks and Old man Emu springs for $650 plus shipping. You’ll need a washer kit to fit the shocks to the LX towers. It’s a PITA to DIY but there are plenty of posts to follow here on Mud.

 

[fanboy]

Thanks. From the pics, does it look like my AHC is too far gone?

The $650 price is for all 4?

 

[ramangain]

Photos and a video here:

2001 LX470 · Shared album ð¸

Tap to view!

photos.app.goo.gl

I'd greatly appreciate some advice whether it would be easier and cheaper to restore AHC functionality or just to buy non-AHC parts (and if so, what parts). All else equal, I'd like to have the AHC, but am not willing to pay much of a cost premium for it. Many thanks for advice.

Well, first you need to hook everything up. See if the pump and motor work by priming it with AHC fluid. Once fluid starts displacing air, you can check for leaks. If no leaks, you can perform the graduation level test to help evaluate if the globes are still good or shot. Finally, you can hook up Techstream to check pressures and perform the individual shock tests. If all is OK, you can then use Techstream to adjust pressures accordingly. If all of the parts and sensors are OK, the total cost would be $200 or less (AHC fluid, 30mm socket, Techstream and cable) ... plus your time to learn and do the actual work.