AHC delete or not to delete on 100 series overlanding build (1 Viewer)

[Sooke]

Happy to help! @suprarx7nut gets the credit.

@suprarx7nut may have been the icing on the cake but it was the response from both camps that provided the pros and cons of each so I could make a decision based on the collective experience of forum members. This is why I am here. Thanks guys... I'll document and share my experience as the build progresses.. cheers

 

[suprarx7nut]

@suprarx7nut may have been the icing on the cake but it was the response from both camps that provided the pros and cons of each so I could make a decision based on the collective experience of forum members. This is why I am here. Thanks guys... I'll document and share my experience as the build progresses.. cheers

Most constructive board around for sure.

 

[MycoManiac]

.

In almost all cases, accurate AHC maintenance and upkeep is less time and money than a conversion.

My only rebuttal to this would be the time part.

IF you maintain the AHC system correctly, meaning replacing worn bushings on all the components front and rear, the time is the same.

Money will usually be less but the work, IMO, is the same amount. Unless you’re willing to ride around on 20 year old rubber that isn’t doing a single thing in the system.

I do miss being able to lower my truck to make it into the parking garage of a Mediterranean grocery store here in town. Never thought about that when taking it out.

 

[suprarx7nut]

My only rebuttal to this would be the time part.

IF you maintain the AHC system correctly, meaning replacing worn bushings on all the components front and rear, the time is the same.

Money will usually be less but the work, IMO, is the same amount. Unless you’re willing to ride around on 20 year old rubber that isn’t doing a single thing in the system.

I do miss being able to lower my truck to make it into the parking garage of a Mediterranean grocery store here in town. Never thought about that when taking it out.

Well you do have a point there, I suppose. If you're replacing the upper cushions on the shocks/rams, then you do approach a common labor input to a conversion. That said, lots of people live on those old cushions just about forever... [ducks head in shame with 16 year old cushions...]

Perhaps I should say:

For the level of freshness most owners maintain on their vehicle, the conversion to new conventional gear takes more time and more money than AHC upkeep.
For the folks really on top of it and replacing all rubber, the conversion to new conventional gear takes more money than AHC upkeep.


Generalizations are hard.

 

[MycoManiac]

Well you do have a point there, I suppose. If you're replacing the upper cushions on the shocks/rams, then you do approach a common labor input to a conversion. That said, lots of people live on those old cushions just about forever... [ducks head in shame with 16 year old cushions...]

Perhaps I should say:

For the level of freshness most owners maintain on their vehicle, the conversion to new conventional gear takes more time and more money than AHC upkeep.
For the folks really on top of it and replacing all rubber, the conversion to new conventional gear takes more money than AHC upkeep.


Generalizations are hard.

Meh. What you said was right.

I was just entirely surprised at how bad the rubber was when pulling it all out. I wonder if I had pics.

Either way, AHC is perfect for 99 percent of folks and the ride is phenomenal when maintained. And not hard to learn and plenty of resources around here. I agree with you on all that man.

 

[medtro]

Perhaps I should say:

For the level of freshness most owners maintain on their vehicle, the conversion to new conventional gear takes more time and more money than AHC upkeep.
For the folks really on top of it and replacing all rubber, the conversion to new conventional gear takes more money than AHC upkeep.

Globes and height sensors are not cheap, some may need a pump too. Conversion can be done with some used components for less if you are not paying someone or a shop for the work.

 

[suprarx7nut]

Globes and height sensors are not cheap, some may need a pump too. Conversion can be done with some used components for less if you are not paying someone or a shop for the work.

AHC repairs can be done with used components as well - often getting parts for free or nearly free. It's also very unlikely someone needs all new globes, all new height sensors and a new motor (nobody needs the entire new pump/motor/reservoir/block assembly). Most folks will encounter new globes and maybe a single height sensor. Replacing all this stuff pre-emptively is on the hyper-cautious side.

New comparisons:

Globes: $700 (brand new full set, Impex)
Height Sensors: $700 (full set brand new, Partsouq)
Motor: $200 (new, motor only, Partsouq)

Total: $1600

Ironman Foam Cell Pro kit: $1500-2500

Keeping both options similar in regards to new/used components I don't think there's a budgetary leg to stand on. In almost all cases it's only cheaper to convert if you or your mechanic is randomly throwing parts at AHC and/or paying the huge markups from a local dealer for counter parts.

 

[medtro]

AHC repairs can be done with used components as well - often getting parts for free or nearly free. It's also very unlikely someone needs all new globes, all new height sensors and a new motor (nobody needs the entire new pump/motor/reservoir/block assembly). Most folks will encounter new globes and maybe a single height sensor. Replacing all this stuff pre-emptively is on the hyper-cautious side.

New comparisons:

Globes: $700 (brand new full set, Impex)
Height Sensors: $700 (full set brand new, Partsouq)
Motor: $200 (new, motor only, Partsouq)

Total: $1600

Ironman Foam Cell Pro kit: $1500-2500

Keeping both options similar in regards to new/used components I don't think there's a budgetary leg to stand on. In almost all cases it's only cheaper to convert if you or your mechanic is randomly throwing parts at AHC and/or paying the huge markups from a local dealer for counter parts.

Not sure on the ideas of using used sensors and globes when there is no good ways to test for their condition or remaining life.

Ironman Foam Cell Pro kit can be had for $1200 if you are patient.

 

[harshjay]

Do you continue to run stock OEM AHC torsion bars and only change the coils depending on weight mods?

I put in Sway-away's TB, and they landed the pressures spot on, with plenty of room for further adjustment if they wear in softer.

 

[Sooke]

I put in Sway-away's TB, and they landed the pressures spot on, with plenty of room for further adjustment if they wear in softer.

Do you run a heavier bumper with winch on front?

 

[uHu]

... I do like the idea of removing the AHC system entirely to alleviate any potential failures in the future and run a standard suspension set up....

I'll start with an anecdote:
When my first 100 were still young, after 2-3 years of carefree driving, I took it onto a forestry/logging road. The road itself was good enough for a Corolla, but there were a few twigs and small branches lying about. After 10-20 meters on this road, a small pine branch managed to tip or twist up to bend the bracket of the rear height sensor. The result was that the AHC tried to compensate for the perceived wrong height by adjusting the rear shocks to one extreme. Can't remember now if it was all the way up until it was stinkbug high (fully extended), or riding the bump stops. But, since I had never examined how the AHC was put together, or knew where the different parts were located, I just had to drive the handful of miles home without a working suspension system.

I have since learned a bit, and I'm keeping the AHC, even after all the problems I had in the beginning because of an ignorant dealer. The AHC system do add a layer of complexity though, but for me the benefits count more (which are already mentioned in this thread). I guess that if I was to cross the antarctic, or the roadless parts of siberia, I would remove the AHC.
Otherwise, I recommend to keep it if you are capable of servicing it yourself. On a proper expedition I would bring spare sensors, with brackets and linkages, and a laptop running TechStream.

 

[Sooke]

I'll start with an anecdote:
When my first 100 were still young, after 2-3 years of carefree driving, I took it onto a forestry/logging road. The road itself was good enough for a Corolla, but there were a few twigs and small branches lying about. After 10-20 meters on this road, a small pine branch managed to tip or twist up to bend the bracket of the rear height sensor. The result was that the AHC tried to compensate for the perceived wrong height by adjusting the rear shocks to one extreme. Can't remember now if it was all the way up until it was stinkbug high (fully extended), or riding the bump stops. But, since I had never examined how the AHC was put together, or knew where the different parts were located, I just had to drive the handful of miles home without a working suspension system.

I have since learned a bit, and I'm keeping the AHC, even after all the problems I had in the beginning because of an ignorant dealer. The AHC system do add a layer of complexity though, but for me the benefits count more (which are already mentioned in this thread). I guess that if I was to cross the antarctic, or the roadless parts of siberia, I would remove the AHC.
Otherwise, I recommend to keep it if you are capable of servicing it yourself. On a proper expedition I would bring spare sensors, with brackets and linkages, and a laptop running TechStream.

Yes I have been educating myself as much as possible on the system. Lots of incredible information here on the forum. At first it was daunting since I didn't know much about the system but now I feel much more confident about keeping up with the general maintenance as well as preemptive replacement of the parts most likely to fail due to wear and tear (height sensors, globes, bushings).

I have a collection of spare parts that I will add to my "to bring" box. It has been reassuring to hear from other members on here that still have the AHC on rigs that have added weight due to bumpers, racks, storage systems, etc. I am learning what needs to be done to compensate for the added weight so that the AHC system remains in spec.

I do have a laptop running tech stream but I have had difficulties getting the VM to recognize the cable.

Thank you for your input.

How do you like the 1HD-FTE? I've been contemplating importing a JDM HDJ-100

 

[harshjay]

Do you run a heavier bumper with winch on front?

victory 4x4 front and rear steel, roof rack and tent, full BJ Landers camp kitchen (steel and baltic birch), smitty 12k winch, 2 dogs (60lbs each) 2 people.

 

[Sooke]

victory 4x4 front and rear steel, roof rack and tent, full BJ Landers camp kitchen (steel and baltic birch), smitty 12k winch, 2 dogs (60lbs each) 2 people.

That's pretty much the same I plan on running in terms of extra gear/ weight. What are you running for coils in the back? Sorry if you had already stated this. I couldn't find it in earlier posts

 

[trdcorolla]

In usual mud forum fashion, some advice for somebody who wanted to prepare and overland their AHC 100 with the least amount of drama.

Non-AHC torsion bars/springs will generally keep most moderately weighted folks afloat even if the AHC fails. You'll need 30mm socket to crank the torsion bars though. Timbren bumpstops will give you added support, should you experience failure. You could probably install Firestone airbags and leave in there at the minimum pressure, if you wanted further backup. If the system does fail, your ride will be horrible but at least you won't be stranded sitting on your bumpstops.

Most common failure are the AHC sensors. They are available through Toyota/Lexus but much cheaper if you buy Aisin (OE supplier).

Aisin sensors
HST-020 (Front Right) (Click here for some cheap ones)
HST-021 (Front Left)
HST-026 (Rear)

Toyota/Lexus fluid is recommended (maybe not lately with the batch of contaminated). I have not used anything else but I believe we can use Pertosin EHF fluid which is available in lots of auto parts stores. It is mineral based like OE Toyota fluid and used by Mercedes and other manufacturers in their Hydropneumatic suspension, similar to AHC with similar accumulators that have a rubber membrane.

There is also Pertosin CHF 11S, used for the same purpose but is synthetic. They say it is compatible with the EHF fluid but I don't know. Best to use the EHF fluid to be on the safe side (if Toyota fluid is unavailable). They do come in 1 and 5 liter quantities.

In the 20 years since I've had a lifted/loaded AHC 100, I've only had one issue, front AHC sensor went bad. YMMV. And I live in a rust-free area.

At what point do you think it's better to replace the AHC torsion bars with Non-AHC OEM LC torsion bars? I know people here are running AHC torsion bars with aluminum front bumpers and a winch (assuming they already have regular steel sliders and/or any metal front skids). I don't know much more adjustment these AHC torsion bars have after all of those mods.

 

[hoser]

The AHC bars can support additional steel bumper and winch (250lbs) up front, granted AHC is working properly. The suspension actually flexes well (or as well as it can be expected).

At 250lbs, non-AHC bars would improve high speed emergency handling, reduce bottoming out on higher speed desert terrain. So the choice depends on the individuals driving style and terrain.

In the event of a failed AHC, I don’t think AHC bars will do well trying to carry extra 250 lbs even if clocked and cranked as much as possible but I haven’t tried it.

 

[theferg]

Figured I'd add my AHC experience for others to consider....

We're now on our 3rd LX470. First was a 2000 LX470 we had for 3 years, then upgraded to a 2005 LX470 we've now had for 6 years, and I just picked up a lower mileage 2006 LX470 a month ago. The LXs have been the wife's grocery-getter/kid-duty/family-vacation vehicle for the last 9 years and we've always had a 2nd vehicle that I primarily used for daily and trail use.

Being the primary vehicle, the 2000 LX was left stock other than a Slee AHC over-ride switch and 285s. When I'd switch from driving my OME equipped Tacoma or GX470 into driving the LX on family trips and outings, I could barely tolerate how s***ty the AHC rode on the LX. But being my wife's primary vehicle, and her never complaining about the way it rode, I never touched it. After 3 years of my wife absolutely loving the LX, she got a bit jealous of the "newer feeling" interior my GX470 had, so we got a 2005 LX470 and I sold the 2000 to a buddy. That buddy promptly had me help him tear out the AHC and install an OME kit. I LOVED the way it rode with the OME kit and felt I shoulda done it sooner.

So I planned to do that at some point on the new 2005 LX470, which my wife also loved and never complained about how it rode. So after about a year of owning the 2005, I tore out the AHC and put in the same OME kit I did in the 2000 for my buddy. I loved it on this one too. My wife said it felt more stiff, but she was fine with it and I've never heard a single complaint. We've taken it a few times out on dirt roads from time to time and it has been great.

Fast forward 80k miles and 5 years, and we've relegated the 2005 to trail duty for me, and bought her the lower mileage 2006 LX470. I traveled by shuttle 4 hours away to pick up the new 2006 LX and then drove it home. The thing absolutely drove like a DREAM. I've never driven an AHC equipped rig that drove this nice. (I have even driven a handful of stock LX570s that were for sale and they did not drive this nice suspension-wise.) There is NO WAY I will be swapping out the AHC on this one any time soon. (And lucky for me, I kept all the AHC stuff I ripped out of the 2005 so I have lots of spare parts now. )

I used to be quite argumentative AGAINST the AHC (mostly in the FB groups) but not in terms of reliability, in terms of ride quality. But I have to say, I have DEFINITELY changed my tune a bit. I now believe that our first two LXs just must not have been maintained as well as our 2006 has been, because they definitely did not ride anywhere near as well as this 2006 does.

And also this:

And unlike most the other failures above, you can limp off the trail or even multiple states on the highway if AHC goes out. A dead sensor might just mean you're stuck in N or a random height. Not necessarily a huge deal. You still have a mobile vehicle. If AHC totally goes out (very unlikely unless it's rusted like a sunken ship), you're stuck on the bump stops. That sucks, but it's far better than a dead alternator, starter, brake booster, etc...

My 4-day trip into the Arizona Strip this past weekend was turned upside-down when my alternator died in the 2005 LX after 2 hours and about 20 miles of off-highway. Lucky for me I was with a small group and we were only 30 miles from my house so we were able to get me pulled back to my house and throw my gear into one of the other vehicles and continue the trip. Had it happened a day further into the trip though, it would have been a MUCH bigger ordeal getting me pulled back home. But I can def say I woulda rather have had AHC fail and still been able to drive myself back home instead of having to get towed.

Me in the rear-view getting pulled back home after the dead alternator:

 

[suprarx7nut]

At what point do you think it's better to replace the AHC torsion bars with Non-AHC OEM LC torsion bars? I know people here are running AHC torsion bars with aluminum front bumpers and a winch (assuming they already have regular steel sliders and/or any metal front skids). I don't know much more adjustment these AHC torsion bars have after all of those mods.

AHC bars are made for ~50% of the factory weight over the front axle. Non-AHC are made for 100%. Weight on the front tires tends to be around 2800 lbs before any mods on a 100 series.

Therefore: AHC T-bars meant for ~1400 lbs. Non-AHC meant for ~2800lbs. I believe AHC hydraulics hold around 1400 lbs at factory specs at neutral height. If we're considering function in N height I think the answer is almost always factory AHC bars. The non-AHC and stronger bars are just way too much spring rate for the factory damping range.

Considering H (as you should if you're going off grid or doing something more extreme like the Rubicon) means that excess spring rate helps to maintain acceptable pressures (and reliability) in H. The adjustments of the T bars for correct N pressure might fall short in H on a heavy rig (because T-bar adjustments change the preload, but not the spring rate).

If your goal is highway comfort in N, AHC bars all the way provided you can crank them enough to keep neutral pressures in check.

If your goal is long term capability in H at the expense of increased harshness, consider the non-AHC bars. Sway Away might be a good compromise in the middle appears to be even stronger than non-AHC.

 

[David*BJ70]

In the event of a failed AHC, I don’t think AHC bars will do well trying to carry extra 250 lbs even if clocked and cranked as much as possible but I haven’t tried it.

Once, a 10mm bolt fell off a front AHC sensor. The ride home from work was perilous (fortunately, only paved city road and highway (+/-20 miles)). The front was very bouncy and the TBs seemed to offer no decent support to my 100 equipped with an ARB front bumper.

 

[jLB]

If your goal is long term capability in H at the expense of increased harshness, consider the non-AHC bars. Sway Away might be a good compromise in the middle.

I was under the impression that the Sway-A-Way bars were a good bit thicker than the non-AHC OE bars.

T bars: OME vs. Ironman vs. ???

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