Thinking of Buying a LX. AHC Concerns

[OG 91 LC]

What up fellas.

I'm so close to buying a 98 LX, two owner, 93k miles, So Cal vehicle for $10k.


Records show it was a lease vehicle and was serviced at Lexus dealer every 10-15k miles up until 57k.

I've been reading on the AHC system and its def a concern for me.

Globes. Fluid. Sensors. Tech Stream. All this stuff is new since I'm more 80 series oriented.

I read that people def dig the AHC system, but there's def a concern.

In the 80 series world we worry or dread the head gasket going out.

In the 100 series world, one that involves AHC, is the AHC system a system you want to avoid????

If there's a thread with this conversation already discussed please paste the link.

I have a check ready to buy, but need advice and your opinions.

Worst case scenario?
AHC stuck in hi/low?

If the system fails in neutral does the system need to be removed to add OME???

Thanks fellas

 

[TXLX100]

I don't think its a system to be avoided. It works really well and very few actual failures. The biggest concern is the ride quality can become poor eventually. The infrequent failures I'm aware of are height sensors and the system being overworked (which can be addressed with maintenance). It's as reliable of a system as any other major system on the vehicle. If it was air suspension, I'd define lay say dump it.... But it's not.

Everyone's hair is on fire because of the price to replace accumulators is somewhat expensive compared to vehicle value. It will cost similar to have the system removed and a decent lift and shocks installed. If it's going to be an on-road / medium off-road vehicle, AHC seems like a winner if it's working properly.

Nice price on the one you are looking at if its in decent shape.

 

[OG 91 LC]

I did forget to mention it drove very well and the AHC system worked just fine. Is it normal for one to press the hi/low function and have to wait a few seconds before the systems lowers or elevates???

Also. This vehicle will become family travels and roof top tent camping vehicle. Mild off-road.

This 100 is in good to great shape. Current owners have driven an average of 2k miles per year in the last 13-14 years. Garaged. Interior/exterior in great condition.


No 90k service.

Fellas. What else should I be looking for in the engine bay/under carriage that may be of concern that I may have missed the first time???

 

[TheForger]

Check common rust-prone areas such as lower shock mounts, sway bar links, and around the spare tire and exhaust.

 

[PADDO]

I did forget to mention it drove very well and the AHC system worked just fine. Is it normal for one to press the hi/low function and have to wait a few seconds before the systems lowers or elevates???

It can take up to 15 seconds to stabilize on a raise and 8 sec to stabilize on a lower, so sounds normal. If the damping is good and responsive to the comfort select switch; it raises/lowers without issue; and you have more than 7 graduations difference on the reservoir when the vehicle is raised from L thru to H then I'd say you're good to go. Ideally you'll be prepared to baseline the AHC fluid (along with all the other fluids I'm sure) and invest the $35 in techstream to tune your pressures and conduct whole vehicle and AHC diagnostics if needed. Its also well worth investing some time to understand the system too and you'll be rewarded with an incredibly capable and versatile system.

 

[TexasCrane]

The AHC is a good system. There are plenty of examples of the it lasting well past 200k miles. If you don't add much additional weight to the vehicle, it's very reliable.

People tend to replace it because when it does eventually fail (and it will because it's a mechanical system just like everything else on a vehicle), it's very expensive to replace the components. It's quite a bit cheaper to remove the AHC and replace it with a traditional suspension.

The only other reason to replace it is if you add bumpers/armor/racks/fridges/etc to the vehicle. The weight just gets too heavy for the AHC. You can address that to a certain extent with heavier duty coils and torsion bars, but that introduces other potential issues. It's generally a safer bet to swap the system out if that's the position you find yourself in.

 

[OG 91 LC]

Are we talking $$$$ thousands $$$$$ to remove/swap the system????

 

[nahtnoj]

Stock for stock, the AHC is vastly more capable than that LC suspension. But if you are planning to lift (and it sounds like maybe you are), get an LC. You'll make things easier on yourself.

 

[TexasCrane]

Most ome kits will run from $1100 to $1800 depending on the options. Install will run about $1k on an ahc vehicle.

 

[OG 91 LC]

I went to pick up the vehicle today. I inspected the AHC fluid reservoir. It was low. It looked dark and not the light pink I have seen on some pics.

As we were driving the seller let me know her husband had fixed some $80 sensor. And boom! Check engine light came on. We tried to get the code read. No deals. (Autozone) She asked if we should take it to Toyota. I asked her to address the issue and smog the vehicle and that I would be back the following weekend.

This LX drives so buttery compared to my '96 80, but there was a (very) slight vibration after 70+. Normal?? tires? Bearings?

I'm really digging this LX.

 

[jemsec]

Most likely tires need balancing.

 

[Mixelplix]

I made the exact same decision you're struggling with. Just yesterday I bought a LX coming from my 91 FJ80.

I read some good advice, which I'll share - someone said (I'm paraphrasing) 'LX AHC's regularly go 200k miles without issue. In 200k miles your conventional suspension should likely be 100% overhauled as well, although people don't. If you're going to have a worn out suspension in a few 100k miles, you should enjoy a superior one while you're doing it'

 

[dasgeek]

I like the ACH system. I have over 230K on mine. I think the globes are starting to weaken as the ride has stiffened slightly. I my decide to pull the ACH and replace with LC setup with a slight lift. I read in one thread on removing the ACH that it weighs about 400lbs so you gain some weight for armor. If you are wanting to make it a little more of an off road setup.

Replace the fluid. It sounds like it needs it. Here is a good thread on changing the fluid. It is a one banana job. You will want two cans of the Toyota fluid.

Enjoy your new truck. They are incredible vehicles.

 

[hankinid]

I like the ACH system. I have over 230K on mine. I think the globes are starting to weaken as the ride has stiffened slightly. I my decide to pull the ACH and replace with LC setup with a slight lift. I read in one thread on removing the ACH that it weighs about 400lbs so you gain some weight for armor. If you are wanting to make it a little more of an off road setup.

Replace the fluid. It sounds like it needs it. Here is a good thread on changing the fluid. It is a one banana job. You will want two cans of the Toyota fluid.

Enjoy your new truck. They are incredible vehicles.

I cannot understand how 4 globes and their mounts, an accumulator and a pump, and the steel tubing connecting everything can remotely approach 400 pounds. Add in 4 shocks which may be heavier than non-AHC shocks by a little, and a few liters of hydraulic fluid and I'm still baffled.

Other than that, I do enjoy the AHC.

Steve

 

[OG 91 LC]

I'm looking forward towards ownership of this LX. I really dig the AHC. I just want to make sure all is good with the system. I still would like to know what Tech Stream does for the AHC. If my understanding is correct it reads values for pressure with in the hydraulic system. The software does or does not adjust levels???

Thanks fellas for your replies and opinions. I have one more week of questions before I make my decision to pick it up.

 

[jhanley]

I've only had my LX a few months, but, ACH has been nothing like the horror stories posted.

Very good ride in comfort mode, great clearance when raised. Pleased so far....

 

[Wilsil]

I cannot understand how 4 globes and their mounts, an accumulator and a pump, and the steel tubing connecting everything can remotely approach 400 pounds. Add in 4 shocks which may be heavier than non-AHC shocks by a little, and a few liters of hydraulic fluid and I'm still baffled.

Other than that, I do enjoy the AHC.

Steve

I have 4 spare globes from someone who removed the AHC system from his car and these globes are heavy.
Add the accumulator and it is starting to go up quickly.

 

[ylexot]

Sounds like a great price for a low miles LX. 90k mile service is due. Sounds like you need fresh AHC fluid too, stat.

I debated the LX vs LX mostly concerned about the AHC. My AHC worked ok for the first few months of ownership. Now I have diagnosed that one or more globes have failed. I'm working on getting replacements. They are expensive and I knew that 150k miles was a typical lifetime, so I was right on the edge. However, compared to the cost of Icon shocks, for example, and the added functionality, I'm going to repair my AHC rather than go OME. Lift when you want it off road, flat towing, drop down to get into low spaces or let short passengers, and cruise around at stock height to save gas. I've even day dreamed about putting one of these suspensions on a project 60 -- not sure if it would work, but I like them that much.

The Techstream is a cheap way to get an ODB2 code reader. Get the Toyota version and you can read the codes and adjust some settings for any Toyota it is programmed for. For the AHC, the Techstream will read AHC pressures and suspension sensor heights. You can't edit anything from them.

On a Level surface drop to Low, look at the fluid reservoir level. Go to High. Look at the reservoir again. If your better than 7 ticks different, you're in serviceable shape. 10-12 is better. My globes are about 6 between High and Low and the ride is pretty rotten: bouncy harsh at the same time. It's terrible. I can't wait to get my AHC back in working order.

 

[OG 91 LC]

Just read your post.

That's my concern. I don't want to buy this LX and then have the system fail within a short period of time. It's a gamble. With the LC no worries, right?

 

[jhanley]

Just read your post.

That's my concern. I don't want to buy this LX and then have the system fail within a short period of time. It's a gamble. With the LC no worries, right?

Dude, stop worrying so much. ANY factory suspension will need replacement after 200k miles.

Use the ACH while it lasts, it's great. Then, replace with OME.