The ABCs of AHC - How to Measure, Flush, and Adjust all in one place (8 Viewers)

[IndroCruise]

Hmm...that's weird. I just looked again and the current USD to JPY conversion puts them at $112 each for me. If you're going to replace all four globes, you will need two of 49141-60010 and two of 49151-60010.

(In my opinion, the term "kit" is misleading as there's only one part in each "kit.")

"Kit" is not a good word -- but each 'globe' usually does include an o-ring and and a back-up ring already fitted. These have separate Part Numbers. It would be unusual for 'globes' to arrived without these -- but suggest check before installing.

It is possible for just one (or even two) 'globes' to fail separately to others -- but it is difficult to discern failure of a single 'globe' and the reality is that if one has failed, the others are not far behind. Therefore suggest always replace the four 'globes' as a set, meaning 2 x 49141-60010 (Front) and 2 x 49151-60010 (Rear). It is normal for the 'globes' to be priced individually.

 

[Mrgreenej]

Thanks guys! So, I'm on the IMPEX site. I have 4 accumulators, a steering telescope motor and am looking into rear springs. On their site they only have 48231-6A740 available and not the other side which is 48231-6A730. Are they the same though, should it matter?? Also, on their site there are no fotos to confirm anything and for the Springs it has a Japanese description. Is this site legit? A rear strut for only $80?? How many of you have actually used it??

 

[IndroCruise]

Late edits added:

Lots of reports by IH8MUD members using IMPEX at this thread:

Impex is LEGIT 4 new AHC globes. Door To Door from Japan, less than 2 weeks

It's criminal what the dealership's charge for these. Got everything in time to change the globes this holiday weekend. All in including enough AHC fluid for 2 or 3 flushes if necessary

forum.ih8mud.com

The post at the link below may be helpful concerning springs for AHC-equipped vehicles -- includes links within the post to relevant official Toyota and Lexus websites in USA which reveal Part Numbers for coil springs -- adjust for your model and year:

Coil springs for AHC

Answering my own post since I found a photo. TLDR: At least one spring with green paint is 48231-6A740, which is LH side for my VIN, US LHD 2004 LX470 with AHC. Click on the camera icon and enlarge one of the photos: Not sure about the label which here says 'RR'. All other documentation...

forum.ih8mud.com

LHD vehicles with AHC have a longer LHS rear coil spring whereas RHD vehicles with AHC have the same length on both sides. Apparently the reason for the longer LHS rear coil spring in LHD vehicles is to provide a little more preload to compensate for driver and fuel being weighted more to the left hand side in LHD vehicles.

Many IH8MUD members with AHC on LHD vehicles and with AHC on RHD vehicles replace/upgrade their OEM rear coil springs with the stronger KING KTRS-79 springs (higher spring rate: OEM are about 95 pounds per inch of deflection whereas KING KTRS-79 are about 130 pounds per inch of deflection).

The KING KTRS-79 coils springs are manufactured in Australia -- sometimes bought direct from the manufacturer or from various distributors and eBay sellers in other countries

These springs are packaged in pairs with both springs of equal length.

Some LHD owners add a small spacer (10mm?) on the LHS when installing KING KTRS-79 rear coil springs.

Suggest use the Lexus site mentioned above to make sure that the correct Part Number is being used for an AHC rear strut. The non-AHC rear strut is quite different and cannot be used on an AHC-equipped vehicle.

LATE EDIT: For Part Number 48530-69145, the IMPEX current price delivered to USA is listed as USD205.13 each by DHL, and USD195.67 each by FedEx. Maybe the USD80 number mentioned by @Mrgreenej was just the shipping cost??

More ....

The AHC Rear 'Shock Absorbers' are not really shock absorbers in the conventional sense but relatively simple hydraulic struts used to adjust the height of the vehicle -- on the road as part of the automatic self-levelling Active Height Control (AHC) feature, or, in response to the console switch height settings, "LO", "N" or "HI". Damping is done by the Damping Force Control Actuator (to which the 'globe' is attached) working together with the 'globe'. Unless the AHC 'shock absorbers' are showing massive rust damage or really major leaks due to long term excessive AHC pressures, they should last almost indefinitely. It is the 'globes' that do require replacement, maybe every10 years plus/minus, not the 'shock absorbers'. Minor leakage at 'shock absorbers' might be overcome simply by ensuring that the AHC pressure are adjusted within the FSM-specified range. Some Owners do choose to change out the AHC 'shock absorbers' rather than replace the lower bush and upper cushion which when on the road can deliver 'clunks' due to age, wear and tear. Even then, the AHC 'shock absorbers' might be re-usable after new bushes and cushions have been fitted.

Removing and re-fitting of the rear AHC 'shock absorbers' is a major PITA task -- do-able but requires much determination. Search IH8MUD first for various tips. If not urgent, suggest save the money and the effort until it is unavoidable.

By the way, it can be helpful to check parts on Partsouq.com. This site provides pictures of most (but not all) parts and also provides alternative pricing. IMPEX pricing usually is sharp but does not always beat Partsouq. Many IH8MUD members use Partsouq.

A few more thoughts on the various Parts Traders can be found by opening the link below to Post #35 -- includes some suggestions at the end of that post about being a cautious Buyer on these sites and being aware of the Seller's conditions of sale.

LX570 accumulators vs LX470 accumulators

I don’t and honestly I probably won’t do it because it works, is 100x better than having blown out globes, and I’m too cheap to go have someone read the pressures. My globes had 400k on them before replacement and the truck is a 1999 and just my spare ride at this point in its life. Techstream...

forum.ih8mud.com

 

[Coin]

Impex is totally legit.

 

[IndroCruise]

See late edits added in original post #343

 

[PabloCruise]

Thanks guys! So, I'm on the IMPEX site. I have 4 accumulators, a steering telescope motor and am looking into rear springs. On their site they only have 48231-6A740 available and not the other side which is 48231-6A730. Are they the same though, should it matter?? Also, on their site there are no fotos to confirm anything and for the Springs it has a Japanese description. Is this site legit? A rear strut for only $80?? How many of you have actually used it??View attachment 3189527View attachment 3189529

P/N for steering column telescopic motor?

As for rear springs, check out the Kings...

 

[Mrgreenej]

P/N for steering column telescopic motor?

As for rear springs, check out the Kings...

Here is the part #8923260022 for the telescoping motor. Mine no longer goes in and out, only up and down and I think I found on some threads here where you need to replace the actual motor. I found it on IMPEX for only $150 instead of $350 through US based Lexus parts distributors.

 

[vvalker]

Please give me some more details and a picture or two. It's crazy that you just posted this because I literally was working on my car today and kicking the tire because I couldn't raise and lower it with the back hatch open.

Here are some photos of the install (Admins, please let me know if there’s a better place to post this, as it’s a little off topic). I have a video I can send, too, which demonstrates the functioning of the switch and how it affects the AHC. If there’s enough interest, I’ll figure out how to upload to YouTube and post a link (please let me know if there’s a better way to share here.)

Hope this helps.

 

[TreatSmash]

Here are some photos of the install (Admins, please let me know if there’s a better place to post this, as it’s a little off topic). I have a video I can send, too, which demonstrates the functioning of the switch and how it affects the AHC. If there’s enough interest, I’ll figure out how to upload to YouTube and post a link (please let me know if there’s a better way to share here.)

Hope this helps.

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Awesome looks easy enough, I have an extra switch just like that sitting right here.

I just don't understand exactly what the switch does other than allow AHC to raise and lower with the rear hatch up when its on (or off?).

Also the wires in the first pic, what were they originally connected to? Did you terminate them yourself?

Thank you in advance for explaining it to me like I'm a moron, I'll go pop the handle on mine this afternoon and see if I can figure out how you got there.

 

[vvalker]

Awesome looks easy enough, I have an extra switch just like that sitting right here.

I just don't understand exactly what the switch does other than allow AHC to raise and lower with the rear hatch up when its on (or off?).

Also the wires in the first pic, what were they originally connected to? Did you terminate them yourself?

Thank you in advance for explaining it to me like I'm a moron, I'll go pop the handle on mine this afternoon and see if I can figure out how you got there.

I cut the black/white wire and added the black wire, spade terminals that I crimped myself, and wire nuts.

I haven't traced it out to figure out exactly what's happening but here's what I imagine is happening: You're interrupting the white/black wire from the sensor that tells the vehicle computer (ECU?) If the hatch is closed. You're putting two switches in series. If either switch is open, the circuit is open, telling the ECU that the hatch is closed. Both switches have to be closed to close the circuit, telling the ECU that the hatch is open. As you know, the AHC won't modulate if any doors are open. But if you open the circuit with the switch, you'll trick the ECU into thinking all the doors are closed, and AHC will function even with the hatch open.

(As always, anyone that knows better, please correct me.)

Good luck!

 

[TreatSmash]

I cut the black/white wire and added the black wire, spade terminals that I crimped myself, and wire nuts.

I haven't traced it out to figure out exactly what's happening but here's what I imagine is happening: You're interrupting the white/black wire from the sensor that tells the vehicle computer (ECU?) If the hatch is closed. You're putting two switches in series. If either switch is open, the circuit is open, telling the ECU that the hatch is closed. Both switches have to be closed to close the circuit, telling the ECU that the hatch is open. As you know, the AHC won't modulate if any doors are open. But if you open the circuit with the switch, you'll trick the ECU into thinking all the doors are closed, and AHC will function even with the hatch open.

(As always, anyone that knows better, please correct me.)

Good luck!

Well in a moment of inspiration I just disconnected the sensor. I had the switch and wires ready to install like yours, but I was thinking I'm probably just going to leave it open. So I tested the AHC with the sensor disconnected and I'm not getting any dashboard, lights or anything so...

I have already installed rear hatch lights so the door light is of no consequence.

Assuming I just want the truck to raise and lower with the rear hatch open can you think of a reason why I couldn't just leave it disconnected without a switch?

 

[vvalker]

Well in a moment of inspiration I just disconnected the sensor. I had the switch and wires ready to install like yours, but I was thinking I'm probably just going to leave it open. So I tested the AHC with the sensor disconnected and I'm not getting any dashboard, lights or anything so...

I have already installed rear hatch lights so the door light is of no consequence.

Assuming I just want the truck to raise and lower with the rear hatch open can you think of a reason why I couldn't just leave it disconnected without a switch?

I suggest you try it and find out. The two things I’ve noticed that bother me when I forget to switch it back is that I can’t lock the doors from my remote (it thinks the hatch is open and makes that annoying tone) and the unlock-auto-relock logic fails if the hatch is open but thinks it’s closed. The difference between what I did and what you’re suggesting is I can just flip a switch if it annoys me. Maybe the things above won’t annoy you and your solution works better for your case. It’s certainly easier in the short term.

 

[TreatSmash]

I suggest you try it and find out. The two things I’ve noticed that bother me when I forget to switch it back is that I can’t lock the doors from my remote (it thinks the hatch is open and makes that annoying tone) and the unlock-auto-relock logic fails if the hatch is open but thinks it’s closed. The difference between what I did and what you’re suggesting is I can just flip a switch if it annoys me. Maybe the things above won’t annoy you and your solution works better for your case. It’s certainly easier in the short term.

Annnnnnnd I locked the keys in the car.

I closed the hatch after it auto locked haha.

Borrowed a coat hanger from the neighbor, got it open, and I'm back at it.

So disconnecting the sensor doesn't stop me from using my fob to lock and unlock the vehicle. It seems the only downside is if I have only the hatch open it thinks the vehicle is closed and I'm inside it so it auto locks.

I guess I have to decide what I find. More annoying, not being able to raise and lower the vehicle with the hatch open or the vehicle locking itself when I have to hatch open.

What I really need is to have a son or daughter and send them to engineering school.

Anyways, I guess I have it from here so thank you for your help.

 

[vvalker]

What I really need is to have a son or daughter and send them to engineering school.

Anyways, I guess I have it from here so thank you for your help.

Hahaha! Good idea! No problem. Happy to help.

 

[GTV]

How do we know if AHC fluid is from the bad batch?

I've got three liters in the plastic bottles that I purchased from McGeorge in May 2021. Closest thing to date codes I can find is an A-1-19, A-1-10 and A-1-24 on the bottom of each bottle, respectively.

 

[medtro]

I would filter it before adding to the reservoir. I used the 2.5L can AHC fluid and I didn't filter it before pouring it into the reservoir. I got gel substances in the reservoir after a few hundred miles.

 

[GTV]

What are we filtering with? Metal screen mesh? Cheesecloth?

 

[y5359]

What are we filtering with? Metal screen mesh? Cheesecloth?

I took out the screen from my ahc reservoir tank and used that.

 

[2001LC]

I would filter it before adding to the reservoir. I used the 2.5L can AHC fluid and I didn't filter it before pouring it into the reservoir. I got gel substances in the reservoir after a few hundred miles.

OH S**T!

You got gel from a 2.5L tin can. Toyota/Lexus very quietly reverted back to the tins. Never issuing a bulletin about gel from plastic bottles. You're first I read found gel, in other than the 1 L plastic bottle.

Have you heard/read of others with gel from a 2.5L tin?

 

[medtro]

OH S**T!

You got gel from a 2.5L tin can. Toyota/Lexus very quietly reverted back to the tins. Never issuing a bulletin about gel from plastic bottles. You're first I read found gel, in other than the 1 L plastic bottle.

Have you heard/read of others with gel from a 2.5L tin?

No, I haven't heard/read of others with gel issue from a 2.5L tin can AHC fluid.