LX570 AHC “Basics” - Added as sticky thread for AHC Issues (3 Viewers)

[radman]

Getting 120K mi service on my '13 this week - not sure if AHC fluid ever changed - is $225 good price for AHC flush?

no price is good for Dealer AHC "flush". Some have reported that this service ONLY includes a 1L topoff into the reservoir.
If you're going to have them do it, specifically ask them if they are going to bleed every corner until the fluid comes out pink.

 

[04UZJ100]

no price is good for Dealer AHC "flush". Some have reported that this service ONLY includes a 1L topoff into the reservoir.
If you're going to have them do it, specifically ask them if they are going to bleed every corner until the fluid comes out pink.

Find out if they even know what they're doing in the first place......

 

[Nihilarian]

…

 

[TXLX100]

Re: common mileage to replace AHC accumulators.
As always, MUD with lot of good information. At what mileage are most people noticing deterioration in the ride quality?

I have a 2011 LX with 145k miles and noticed the ride is a bit more harsh than I’d expect (wife’s car I don’t drive it much).
I think the fluid was changed periodically but can’t say it was done strictly every 30,000 miles.

Can I expect a significant improvement in ride quality with new globes? Should I change the rear springs at the same time to help with system pressure? TIA

 

[paulunm]

I think 10 years or 100k miles.

 

[lx200inAR]

Played with my rear sensors a little today for science. At this point my sensors have been played with enough, that there is no telling what is right or wrong with them.

i have some thoughts on a more accurate approach at doing a sensor lift and also getting back to stock. I didn’t have time to fully vet out the thoughts, but the proof of concept worked out.

Ultimately my only goal today was to lower my rear end a little (I decided on 10mm). I think I can feel the horizontal left to right shimmy of my rear end because it’s lifted a bit. It’s not bad but I can feel it in the seat of my pants.

tools needed:

2 10mm wrenches
Either Techstream on a long cable or wireless, or OBD fusion with the AHC dashboard I shared earlier in this thread (I think, but definitely in the OBD Fusion thread). You need to be able to see the display while under the vehicle.

I put the truck on a somewhat flat surface and parked. Then did a N to L to N cycle and held the brakes a bit. At this point my height sensors were within 2mm of 0 Height registered.

i then turned AHC off and cut the ignition. OBD Fusion still reported sensor height after turning off the truck. The ECU was still working with ignition fully off for at least 30 seconds or so, but I put the car back in accessory mode just in case and it stayed on for 30 min or so while I messed with the sensors (I assume indefinitely until the battery dies).

I then climbed under the truck and loosened the US drivers side sensor. As an experiment I moved this sensor through its entire range in the bracket. The entire range was 30mm total (-13mm to 17mm). Then for giggles I disconnected the arm from the bracket to see what the total range was. My OBD Fusion dashboard has a range set to +-100mm and the sensor maxed out both directions. I didn’t bother reprogramming the widget to see what the ultimate range was. One interesting tidbit was that when you moved the sensor abruptly to an extreme the suspension stiffens up to max valving. Generally when just parked its sits in the middle at step 8, but it would switch to step 16 every time I would swing the sensor.

So here’s the fun part, it’s totally possible to move the sensor where you want based on the ECU height readings and lock the sensor down. I was able to lock the sensor down at 9.2 on driver and 9.5 on passenger, and I was in an uncomfortable position wedged under the truck. The theory is that if I lock down the sensor at about 10mm, when I turn AHC back on, because I’m in mode N (N=0) that the ECU will lower the truck 10mm and that will be my new N position. If you want to go up, swing the sensor to a negative number and the ECU will lift to get you back to 0. After getting the sensors set, I started the truck up, turned Ahc back on and waited for the magic. I thought it might adjust on its own and maybe would have if I waited long enough, ultimately I did a circle around the parking lot, it lowered almost immediately once I got going.

Interesting tidbit number 2. On my 2010, and I know at least some others, the rear passenger sensor is not a mirror of the drivers side. The bracket is very different with a smaller adjustable range and at a slightly different angle. Interestingly enough, the range of readings within this bracket was greater than the drivers side, even though the actual range of motion was smaller. Not really that important a fact unless you are blindly moving sensors like most of us have. This probably explains why a lot of Techstream screenshots of AHC lifted trucks show the passenger side 20-25mm higher. I suspect the passenger rear lifts/drops about twice as much based on how much the sensor is moved.

So the real fun part. Since all this is possible, you can easily jack your truck to whatever height you want it to be, then fiddle with the sensors until they say 0, and you are good to go. With that method, some care has to be taken with being on level ground. Alternatively, use the FSM to set the height based on the suspension components outlined and add or subtract whatever height, then set the sensors to 0, then you don’t even need to be concerned with level ground.

I didn’t bother measuring anything, I have no reason to believe that the truck didn’t lower the 10mm. On my short ride home I did feel like it made a difference, although entirely possible it was a placebo effect. I will say I did a N to L after, which my truck has trouble with, and it worked perfectly (although I only tested once so could have been a fluke).

The last piece to this puzzle, and I don’t know the answer is what the affect of the offset adjust is. Its function is to help calibrate the sensors if you follow the FSM plan with the Height offset utility. What I don’t know is when that value is added to the equation. The value can be between -20 and 20 mm, which is fairly significant. Does this value get factored in before Techstream shows you the height value or after. The question is, does the AHC ECU still target 0 and in the background it’s taking the value read from the sensor, adding the pad from the Height Offset Utility, and then displaying the height to you. Or is the target moved and if you have all your offset values set to 20mm, does that mean now that N=20. My guess is that it’s the former, But we kind of need to know one way or the other.

Either way, happy adjusting!

 

[Willie G]

Both my Lexus and Toyota online parts sources show 08886-01805 and 08886-81260 as "Discontinued, No Longer Available."

There is a vendor on Amazon that claims to have AHC fluid, but I am dubious.

Has anyone used the Ravenol AHC Fluid? Thoughts? Suggestions?

Ravenol AHC Fluid

 

[32cls6speedmt]

Toyota Suspension Fluid 08886-01805 | Toyota Parts

Genuine Toyota 08886-01805 - Suspension Fluid. Toyota Online Parts is your choice for Toyota Parts and Toyota accessories. We are a factory authorized Toyota Dealer with Toyota parts and Toyota accessories all at wholesale prices for your Tundra, Tacoma, Camry, Corolla, RAV4, 4Runner...

toyotaparts.ourismantoyotaofrichmond.com

It shows it is in stock.

 

[Willie G]

Toyota Suspension Fluid 08886-01805 | Toyota Parts

Genuine Toyota 08886-01805 - Suspension Fluid. Toyota Online Parts is your choice for Toyota Parts and Toyota accessories. We are a factory authorized Toyota Dealer with Toyota parts and Toyota accessories all at wholesale prices for your Tundra, Tacoma, Camry, Corolla, RAV4, 4Runner...

toyotaparts.ourismantoyotaofrichmond.com

It shows it is in stock.

Thanks a bunch! Ordered 2 cans!

 

[JR1899]

I'll add some data points to the conversation. I have been debating replacing my globes as I have a relatively low mileage (60k) 2015 LX. But the truck is almost 10 years old now. When I purchased the truck last year (at 43k miles) I did an AHC flush immediately. Raising and lowering was quicker and smoother, and the truck rode great. Recently, I noticed a little more lean in the corners, slightly harsher impacts on small dips and expansion joints, and the trick relieving pressure and dropping suddenly in front after shutting off the vehicle and exiting. Overall, I still felt like the truck rode great; it seemed slightly rough sometimes. I researched and researched globe replacement. I never really saw anyone replacing them at as low of miles as I currently have, though. I have seen many mention time as a factor, so I decided to pull the trigger and order some globes. Put them in this weekend and was blown away. I guess I didn't realize how poor the ride and control had gotten. It seems like a brand-new truck. What I had thought was tires out of balance (have been chasing that with several balances and rotations) was just vibrations at speed from the suspension. The truck feels rock solid at speed now and smooth as butter. Small bumps are almost non-existent. I can't believe the difference and am happy I replaced them. I understand the placebo effect, so I didn't let my wife know that I was changing them. We went to dinner last night, and she commented that the truck seemed like it was riding smoother and not as rough over imperfections in the roadway. . Guess that is proof that they do make a significant difference. If your truck is creeping up on 10 years, regardless of mileage, I'd totally recommend new globes!

 

[chuckd83]

First time poster, but this thread has been a huge wealth of knowledge. Thank you to those who have contributed! I just purchased a new to me 2015 LX570 last week and wanted to catch up on some possible missed maintenance items, and the AHC flush is one of them. I also wanted to check the health of the accumulators and had only seen the health check referenced very briefly.

Digging into the repair manual and I found this easy check, similar to the LX470 check. As it turns out, the LX570 does have graduation marks on both the front and back of the reservoir tank. In order to see the marks on the front of the tank, you have to crawl under the truck as shown below. You can also take of the rear trim pieces to view the graduation marks on the back of the tank. It should go without say, but don't be laying under the truck while it's in the process of changing heights.

View attachment 2997024

Here's a wide angle shot to provide some perspective.
View attachment 2997026

Enhance....
View attachment 2997027

Enhance...
View attachment 2997030


My driveway is on an incline and the the truck is not level, however, I do appear to get 8+ marks between low and high.

Low:
View attachment 2997031

High:
View attachment 2997030

Where in the repair manual did you find that section?

 

[breyenger]

Just tried sensor lift on my JDM ZX with AHC.

Looks like I got 1.25 inches out of the front and .75 inches in the rear there abouts.

I have tech stream but I haven’t bothered to check. Looks good but will have to report back on ride.

What’s the consensus on running just the sensors maxed out these days? Should I adjust/add anything else to make it more reliable? It’s got 40km on the clock and globe’s likely never flushed/changed.

 

[tbisaacs]

View attachment 3542216View attachment 3542217
Just tried sensor lift on my JDM ZX with AHC.

Looks like I got 1.25 inches out of the front and .75 inches in the rear there abouts.

I have tech stream but I haven’t bothered to check. Looks good but will have to report back on ride.

What’s the consensus on running just the sensors maxed out these days? Should I adjust/add anything else to make it more reliable? It’s got 40km on the clock and globe’s likely never flushed/changed.

Mine have been maxed out since 2018

 

[skrypj]

Can you run AHC shocks on Tundra control arms? I've looked around and it looks like most people who have run the Tundra arms are deleting AHC.

I do remember that one guy did the build with the 4" Tundra lift and 37's and I think kept AHC so I think its possible.

 

[tbisaacs]

Can you run AHC shocks on Tundra control arms? I've looked around and it looks like most people who have run the Tundra arms are deleting AHC.

I do remember that one guy did the build with the 4" Tundra lift and 37's and I think kept AHC so I think its possible.

yep. Lots of folks do it and keep AHC.

 

[TeCKis300]

Can you run AHC shocks on Tundra control arms? I've looked around and it looks like most people who have run the Tundra arms are deleting AHC.

I do remember that one guy did the build with the 4" Tundra lift and 37's and I think kept AHC so I think its possible.

Nothing wrong with that. You'll also have to look at the other parts and how you're going to package this all in. Meaning there's limited width before going past the fenders. Compression travel is pretty deep and puts even a 33" well under the fender lip. With 1.5" wider tundra arms, and necessary offset (another 1-1.5" to clear suspension and frame, you'll have to begin cutting the fenders, body lift, or both. Perhaps dramatically depending on desired tire size.

 

[skrypj]

Nothing wrong with that. You'll also have to look at the other parts and how you're going to package this all in. Meaning there's limited width before going past the fenders. Compression travel is pretty deep and puts even a 33" well under the fender lip. With 1.5" wider tundra arms, and necessary offset (another 1-1.5" to clear suspension and frame, you'll have to begin cutting the fenders, body lift, or both. Perhaps dramatically depending on desired tire size.

will the AHC provide enough downtravel to max out the longer Tundra CV's and ball joints? I other words could you just spacer the AHC shocks and then run extended bumps and gain extra downtravel?

I was under the impression that the AHC shocks were limited in travel to being with.

 

[lx200inAR]

will the AHC provide enough downtravel to max out the longer Tundra CV's and ball joints? I other words could you just spacer the AHC shocks and then run extended bumps and gain extra downtravel?

Check here

Long Travel AHC

Probably no surprise, but I've been a big proponent oh AHC. Damping always dialed in regardless of load. Large fluid volumes and remote accumulator damper that stays cool with extended off-road travels. Actively pressurized for long term performance and durability. Combined with unique...

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