AHC Height Sensors question

[RoderickGI]

For the record, the 2000 LX weighs in at 5401 lbs versus 5115 lbs for the same year LC. So less than 300 lb difference. For 2007, the difference is 165 lbs.

My numbers are different but the difference in weight works out similar. My Australian 1998 LX470 has a Kerb (Tare) Weight of 2525 Kg (5566 lb). A 1998 LC100 series varies in Kerb Weight from 2230 to 2405 Kg. The closest specification to the LX470 is the 4.7 Litre V8 Petrol Automatic GXV, with a Kerb Weight of 2405 Kg (5302 lb). This gives a difference of 120 Kg (265 lb), which is your 'less than 300 lb'. I'm not sure where all that weight is though. The GXV could have eiter IFS or a live front axle in 1998. The LX has a rear diff locker standard, which was optional on the GXV.

Anyway, you are right. The weight difference isn't that big. But we don't know the distribution: high or low.

hey roderick what globes are you going to get?? what company? let us know how it works out.

The only after market globes I have found are from B&B Suspension. Keith Bowers from B&B (Texasoil on this forum) has been most helpful.

i really dont think the ahc systems between 06 07 models and earlier years are the same.

I have no doubt that the system was improved over time, and it could be that the '06 and later AHC system has more functions. I just know that the AHC is actually called "Active Height Control Suspension" and is part of the "Adaptive Variable Suspension" in the 1998 LX470. It controls Dive, Squat, and Body Roll in addition to vehicle height and the damping force of the suspension. It take readings from two independent Front Height Control Sensors and the one Rear Height Control Sensor, in addition to a Steering Angel Sensor in the steering wheel, two Front Speed Sensors in the front wheels, and various switches and controls. The testing procedure in the Workshop Manual covers an awful lot of stuff.

So while I agree that the 1998 AHC doesn't have independent control of the four corners of the vehicle, it is a bit more than just a hydraulic lift. I find it is a great advantage when travelling off road, and would hate to lose the functionality by replacing the AHC with standard TBs, coil springs and shocks. I don't go rock crawling, but I have had need of the High setting when crawling up or across rocky roads, up steps, through river crossings and so on. That little bit of lift, on demand, is great.

 

[shiretowndown]

Resurrecting an oldie here but it speaks directly to my recent concern:

A slight lean to driver side when I have parked and lowered my ‘01LX in my level garage.

stock
241,000 miles

i dont know anything about torsion bars and as far as reading pressures, is this something I can only do with TechStream and a laptop?

 

[IndroCruise]

Resurrecting an oldie here but it speaks directly to my recent concern:

A slight lean to driver side when I have parked and lowered my ‘01LX in my level garage.

stock
241,000 miles

i dont know anything about torsion bars and as far as reading pressures, is this something I can only do with TechStream and a laptop?

Select "N" height (not "LO" nor "HI") and 'cross level' the front of the vehicle using the Torsion Bar adjusters and the attached highlighted section of the FSM. The Torsion Bar adjusters are attached by a bracket to the chassis rail on the Right and Left sides of the vehicle, below the front doors.

Some of the very old posts in this thread are incorrect -- understandable, people were still learning the differences between AHC and non-AHC vehicles. In an AHC vehicle, be aware that with the front wheels straight ahead OR with the engine/AHC "OFF", the gate valves in the Control Valve Assembly are open, meaning that Right and Left sides of the AHC system are at the same pressure and exerting the same force on both sides to support the vehicle. The only variable is a possible difference in the force exerted by different torsions in the torsion bars which would give rise to a 'lean'. Attempting to 'fix' a lean using the AHC Height Control Sensors is an exercise in hydraulic futility -- it cannot be done. Use only the Torsion Bar adjusters to correct any 'cross level' problem as described in the FSM extract.

If the vehicle is too high, then adjust height using the Height Control Sensor adjusters (not the torsion bar adjusters) -- search IH8MUD for more details.

To fix AHC front pressures, the Right and Left Torsion Bar adjusters are both wound in the same direction -- for example, clockwise looking up from below the adjusting bolt to increase the torsion bar load and reduce the AHC pressure.

A general description about torsion bars with some some good illustrations are found in the attached document prepared long ago by IH8MUD Member @Gunney. Note that this article is about NON-AHC vehicles, so read it only to understand how a torsion bar works but NOT how to adjust torsion bars on an AHC vehicle.

This long thread provides good material on how to get Techstream running:

How-To: TechStream In 5 Minutes

There are other readers -- but I will leave it to more expert others to identify these.

By the way, if you need a general introduction to the AHC/TEMS system, the following reference is a good place to start:

https://lc100e.github.io/manual/
Look for the index tabs starting at top left hand side of the opening page and choose these tabs in order to reach the General Description document:
New Car Features > CHASSIS > Suspension > Active Height Control Suspension.

 

[shiretowndown]

Wow, thanks @IndroCruise !

Im gonna read through this today, I’ll upload a pic of my lean issue for reference.

 

[shiretowndown]

Below are pics from this cold morning in AL.

2001 LX470 241,000 miles, it’s really clean underneath, i changed the transfer case fluid last night and noticed there was a pink paint mark “sealing” the fill bolt....dont know if it’s ever been done

Anyways, my concern is the lean to the drivers side. I lower my rig each time i park for the night. I feel it gives me a better AHC ride to start the day (something about the chemicles and bubbles in the fluid ). I have noticed this lean for 2ish weeks now.

 

[LXKevin]

Have you changed the rear tailgates to an earlier year?

 

[shiretowndown]

I have not changed anything on this vehicle except wipers and Xfer case fluid. I have only had it 2 weeks or so. This is my 3rd LX.

 

[LXKevin]

I have not changed anything on this vehicle except wipers and Xfer case fluid. I have only had it 2 weeks or so. This is my 3rd LX.

Yea sorry saw the 06LX above didn't pay attention to "Sandy"/color and thought you had swapped an earlier years tailgates for some reason. Have a good one.

 

[shiretowndown]

I backed “Ducky” out of the garage as the day is going to be nice.

“Ducky” is in High mode in these pics.

IF the lean to driver side still exists it isnt noticeable in High mode.

I will mention that when I drop the vehicle to LOW (at night) or HIGH there is a noticeable “creaking” sound??? Almost gives me the audible impression that some ~rubber~ moveable suspension component is aged/hardened.