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

[Sooke]

Hey fellow mudders,

I have a 98 LX 470 with 180,000 kms that I've owned and religiously maintained since 80,000kms on odometer. It is currently bone stock except the removal of the factory running boards. I am looking at adding a front bumper with winch ( I do have the option to go with aluminum for weight savings), drawers in rear compartment, expedition style flat roof rack to accommodate a RTT, and possibly a rear bumper with dual or single swing out.

It will be used for overland travel with a family of four, not serious off roading and rock crawling. I will also be towing a smaller overland style trailer with a tongue weight of less than 300 lbs.

The AHC system runs flawlessly, has been flushed, new ride height sensors installed, and has new accumulators.

I plan on replacing the stock torsion bars with OME torsion bars and front and rear springs with OME coil springs to help with the increased vehicle weight and anticipated payload. I'll use tech stream to see the accumulator pressures after the build and adjust or re-index torsion bars as needed to keep accumulator pressures within spec.

So the big question is will the AHC be able to accommodate the increased vehicle weight, increased payload, the trailer tongue weight, and the rigours of overland travel?

I enjoy the ride quality and ability of switching the shock dampening as well as adjusting ride height based on how the vehicle is being used. But with that being said 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.

It would be great to hear from people who have done what I am proposing to keep the adjustability of the AHC and how it worked out for them as well as others who have removed the AHC in favor of conventional suspension set-up for reliability.

Thanks in advance for your input..

 

[MycoManiac]

First, that’s too much help for the AHC. Try springs out of a stock LC, and then stock LC coils. Or kings. The OME gear will give you a terrible ride. Too much of a load off of the system.

AHC works fine and is a nice system. My personal thoughts are that by the time you get the AHC up to par, you’ve put in the same amount of work and pain to switch to conventional, and possibly more money, depending on how thrifty you are.

I’ve pulled two AHC out of these trucks. Both times the trucks were 01. The bushings on every single end of every single shock was beyond toast.

I agree the system is wonderful and works well, but all that is pointless if your rubber is shot. And I’d rather replace with regular suspension. Personal preference.

The rubber is my only counter to the “keep the AHC “ crowd, and it’s rarely talked about. But it’s a big one for me. And I’d rather not have a height sensor or something else go out a hundred miles into nowhere. I know that you can have things break on a regular suspension, but I’ve never had that happen on any vehicle I have owned, and I had a couple issues with AHC. Regardless of the reason. My experiences with the two.


To add. There are several people here who run fully loaded rigs on AHC. I believe most have switched to LC torsion bars, eith 80 coils or stock LC coils. It’ll handle what you’re wanting to do.

 

[porkandcorn]

Alsolutely do NOT delete. I love my AHC system - in fact I sold my 04 and bought an 06 to get it, before my overland build. It's great for a daily driver, great for camping when you need to lower the vehicle down to comfort height, and great for trails when you need clearance. Understanding and tuning the system is not that difficult, and it's very robust. I can help you understand how to account for added weight, and all that. I'm running regular Non-AHC LC coils, cause I have an 8,000 lb. pig with me, my wife and my cat loaded up. Message me for my phone number, and we can talk about it.

 

[jLB]

Hey fellow mudders,

I have a 98 LX 470 with 180,000 kms that I've owned and religiously maintained since 80,000kms on odometer. It is currently bone stock except the removal of the factory running boards. I am looking at adding a front bumper with winch ( I do have the option to go with aluminum for weight savings), drawers in rear compartment, expedition style flat roof rack to accommodate a RTT, and possibly a rear bumper with dual or single swing out.

It will be used for overland travel with a family of four, not serious off roading and rock crawling. I will also be towing a smaller overland style trailer with a tongue weight of less than 300 lbs.

The AHC system runs flawlessly, has been flushed, new ride height sensors installed, and has new accumulators.

I plan on replacing the stock torsion bars with OME torsion bars and front and rear springs with OME coil springs to help with the increased vehicle weight and anticipated payload. I'll use tech stream to see the accumulator pressures after the build and adjust or re-index torsion bars as needed to keep accumulator pressures within spec.

So the big question is will the AHC be able to accommodate the increased vehicle weight, increased payload, the trailer tongue weight, and the rigours of overland travel?

I enjoy the ride quality and ability of switching the shock dampening as well as adjusting ride height based on how the vehicle is being used. But with that being said 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.

It would be great to hear from people who have done what I am proposing to keep the adjustability of the AHC and how it worked out for them as well as others who have removed the AHC in favor of conventional suspension set-up for reliability.

Thanks in advance for your input..

 

[GTV]

Alsolutely do NOT delete. I love my AHC system - in fact I sold my 04 and bought an 06 to get it, before my overland build. It's great for a daily driver, great for camping when you need to lower the vehicle down to comfort height, and great for trails when you need clearance. Understanding and tuning the system is not that difficult, and it's very robust. I can help you understand how to account for added weight, and all that. I'm running regular Non-AHC LC coils, cause I have an 8,000 lb. pig with me, my wife and my cat loaded up. Message me for my phone number, and we can talk about it.

I agree with this. It's essential to be familiar with the system if/when any issues do pop up. It's really very simple. Get comfortable with it.

Seconded that the OME springs will be way too much with AHC. I'm personally considering rear air bags to lightly assist with extra weight and they could also be pumped up in case there is a rear failure. They are inexpensive, won't ruin the ride and as a bonus they are adjustable from side to side (to easily level out at camp.)

I'd keep a set of height sensors on board. A faulty one can really ruin your day.

 

[porkandcorn]

I agree with this. It's essential to be familiar with the system if/when any issues do pop up. It's really very simple. Get comfortable with it.

Seconded that the OME springs will be way too much with AHC. I'm personally considering rear air bags to lightly assist with extra weight and they could also be pumped up in case there is a rear failure. They are inexpensive, won't ruin the ride and as a bonus they are adjustable from side to side (to easily level out at camp.)

I'd keep a set of height sensors on board. A faulty one can really ruin your day.

Agreed on coils:

I learned this, by trying all three unwittingly to get the right balance.

No weight mods: OEM AHC coils
Medium weight add: King Springs
Large weight add: Non-AHC coils

 

[trdcorolla]

I don't have off-road bumper's or a winch on my AHC 100 but I do have sliders, roof rack, skids and about 30lbs of junk behind the 3rd row. My front fender to center hub is 19.75" and my rear fender to center hub is 20.5". My front AHC pressure is 6.4 Mpa and my rear pressure is 5.9 Mpa. I have AHC torsion bars and King springs. With the weight your talking about, I don't think the King springs will be enough for you, you'll probably need OEM non AHC springs and maybe a 30mm spacer.

 

[David*BJ70]

The problem with the AHC is that it works fine but if one component fails, it doesn't work at all (nearly). It would be unfortunate to lose it all when you are far from civilization especially since replacement parts are only available from Toyota or Lexus, even the fluid AHC.

Being Canadian, (Québec), there is very limited support here for expertise and parts. Moreover, I venture into some REALLY isolated areas (such as Trans-Taïga or Anticosti Island). So I decided to remove my AHC to avoid transforming my overland trips into a nightmare My HDJ100 weighs 7500+.


It all depends on the reliability of your AHC and your risk tolerance.

 

[Sooke]

First, that’s too much help for the AHC. Try springs out of a stock LC, and then stock LC coils. Or kings. The OME gear will give you a terrible ride. Too much of a load off of the system.

AHC works fine and is a nice system. My personal thoughts are that by the time you get the AHC up to par, you’ve put in the same amount of work and pain to switch to conventional, and possibly more money, depending on how thrifty you are.

I’ve pulled two AHC out of these trucks. Both times the trucks were 01. The bushings on every single end of every single shock was beyond toast.

I agree the system is wonderful and works well, but all that is pointless if your rubber is shot. And I’d rather replace with regular suspension. Personal preference.

The rubber is my only counter to the “keep the AHC “ crowd, and it’s rarely talked about. But it’s a big one for me. And I’d rather not have a height sensor or something else go out a hundred miles into nowhere. I know that you can have things break on a regular suspension, but I’ve never had that happen on any vehicle I have owned, and I had a couple issues with AHC. Regardless of the reason. My experiences with the two.


To add. There are several people here who run fully loaded rigs on AHC. I believe most have switched to LC torsion bars, eith 80 coils or stock LC coils. It’ll handle what you’re wanting to do.

Thank you for sharing your AHC delete experience. Is changing the rubber out as simple as conventional shock mount rubbers? That's a very good point, I have overlooked mine, I'll take a look at the condition of mine. I have been replacing all other rubber bushings so I can add them to my list.

There have been a couple other who have said similar in terms of using the OME gear and creating a harsh ride. That is definitely something I don't want to do since the ride quality is the main reason for potentially keeping the AHC.

 

[Sooke]

Alsolutely do NOT delete. I love my AHC system - in fact I sold my 04 and bought an 06 to get it, before my overland build. It's great for a daily driver, great for camping when you need to lower the vehicle down to comfort height, and great for trails when you need clearance. Understanding and tuning the system is not that difficult, and it's very robust. I can help you understand how to account for added weight, and all that. I'm running regular Non-AHC LC coils, cause I have an 8,000 lb. pig with me, my wife and my cat loaded up. Message me for my phone number, and we can talk about it.

Thank you kindly, message being sent. I love my AHC. It has been our family daily driver for the past 8 years. Lots of family road trips, camping, etc. I have been reading as much as I can on here about the system so I do have a better understanding of how it works.

 

[MycoManiac]

Thank you for sharing your AHC delete experience. Is changing the rubber out as simple as conventional shock mount rubbers? That's a very good point, I have overlooked mine, I'll take a look at the condition of mine. I have been replacing all other rubber bushings so I can add them to my list.

There have been a couple other who have said similar in terms of using the OME gear and creating a harsh ride. That is definitely something I don't want to do since the ride quality is the main reason for potentially keeping the AHC.

My personal experience, nope.

The rear shocks and the resulting hardware for it all, is one of the most annoying things I’ve worked on on these trucks.
It’s not hard, just annoying. Hard to get spots. Tools make a huge difference.

I perosnallly don’t have a problem with OME suspension. It’s not a Slee ride, or Radflo, but I don’t find it near as harsh as people here like to parrot.

It’s a firm truck suspension. AHC rides better for sure. But it’s luxury versus truck ride. Not like you’re driving a horse drawn carriage. I think some people just like to repeat what they heard one or two folks say

 

[Sooke]

My personal experience, nope.

The rear shocks and the resulting hardware for it all, is one of the most annoying things I’ve worked on on these trucks.
It’s not hard, just annoying. Hard to get spots. Tools make a huge difference.

I perosnallly don’t have a problem with OME suspension. It’s not a Slee ride, or Radflo, but I don’t find it near as harsh as people here like to parrot.

It’s a firm truck suspension. AHC rides better for sure. But it’s luxury versus truck ride. Not like you’re driving a horse drawn carriage. I think some people just like to repeat what they heard one or two folks say

Ah yes. I don't mind a day of cursing and bleeding knuckles...

I am open to whatever suspension set up is needed to keep the ride quality. It is our daily family vehicle and when not used for overland camping etc will still be used as our daily.

Now riding in my 61 with OME is like riding in a horse drawn carriage if not fully loaded for the trails.. ha but it serves its purpose..

 

[Sooke]

I agree with this. It's essential to be familiar with the system if/when any issues do pop up. It's really very simple. Get comfortable with it.

Seconded that the OME springs will be way too much with AHC. I'm personally considering rear air bags to lightly assist with extra weight and they could also be pumped up in case there is a rear failure. They are inexpensive, won't ruin the ride and as a bonus they are adjustable from side to side (to easily level out at camp.)

I'd keep a set of height sensors on board. A faulty one can really ruin your day.

Thanks for the air bag suggestion. I have also read about the rear helper system timbren offers. It isn't an air system and won't allow for side to side adjustment. I just recently changed out all ride height sensors as preventative maintenance so I'll have a full set of spares to add to my parts kit.

 

[OwnerCS]

If you are keeping AHC for the long term, check the lower mount bushings for wear and consider replacing.

 

[ChaoticSquare]

If you are keeping AHC for the long term, check the lower mount bushings for wear and consider replacing.

View attachment 2929365

The lower mount is the “easy” one to replace. It’s getting the rear upper off that frustrates people. I’d keep AHC, but I understand the reasons to dump it thy people have.

 

[Sooke]

The problem with the AHC is that it works fine but if one component fails, it doesn't work at all (nearly). It would be unfortunate to lose it all when you are far from civilization especially since replacement parts are only available from Toyota or Lexus, even the fluid AHC.

Being Canadian, (Québec), there is very limited support here for expertise and parts. Moreover, I venture into some REALLY isolated areas (such as Trans-Taïga or Anticosti Island). So I decided to remove my AHC to avoid transforming my overland trips into a nightmare My HDJ100 weighs 7500+.


It all depends on the reliability of your AHC and your risk tolerance.

View attachment 2929280

I completely agree with you in the potential for failure of the system when away from any resources. I too live in Canada, in BC and have found that there isn't much at all for expertise and parts. I'm thankful for the collective expertise here on mud and the members willingness to share. Thats a great looking rig. On a side note how do you like the 1HD-FTE? Do you have an automatic or manual paired to it? I've been contemplating importing one. My only concern would be parts etc when overlanding with that engine not being offered in North America. I currently have a 61 with the 12H-T that I have traveled extensively through the US and mexico without issue.

 

[Sooke]

If you are keeping AHC for the long term, check the lower mount bushings for wear and consider replacing.

View attachment 2929365

With these type of bushings I'd imagine the whole shock has to be removed to facilitate getting the old out and the new in? These don't look to be ones that just pop out but need to be cut or pressed?

 

[Sooke]

Agreed on coils:

I learned this, by trying all three unwittingly to get the right balance.

No weight mods: OEM AHC coils
Medium weight add: King Springs
Large weight add: Non-AHC coils

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

 

[OwnerCS]

With these type of bushings I'd imagine the whole shock has to be removed to facilitate getting the old out and the new in? These don't look to be ones that just pop out but need to be cut or pressed?

No experience with replacement. I photographed those after removing them for replacement.

 

[jLB]

I perosnallly don’t have a problem with OME suspension. It’s not a Slee ride, or Radflo, but I don’t find it near as harsh as people here like to parrot.

It’s a firm truck suspension. AHC rides better for sure. But it’s luxury versus truck ride. Not like you’re driving a horse drawn carriage. I think some people just like to repeat what they heard one or two folks say

Parrot?

I’ll disagree here.

I’m one of those that’s not an OME shock fan.

We’ve had the OME shocks on my son’s 2000 TLC for about 8 years now. We’re just getting around to replacing them now.

Taken by themselves, the OME shocks have a firm truck ride, that can be somewhat tolerated.

When compared to some of the other aftermarket options, they just seem overly harsh and punishing, both on road and off.

I believe using the word “comfort” in the same sentence as “OME shocks” (the yellow twin tubes available for the IFS 100) should be illegal.

YMMV