AHC Disappointment

[ycookmd]

For the first year I've had the Land Cruider, I've been very happy with the AHC, using it just a few times for light offroading. However, I've had 2 recent experiences that make me think AHC was the wrong way to go, and I'd advise new purchasers to steer away from AHC.

A few weeks ago I drove out to the deer lease to fill the feeders. The load consisted of me, a cooler with a few drinks, some assorted gear and 12 40-pound bags of corn. The total load could not have been more than 750 pounds maximum, but when I got to the lease and attempted "high" to get around and through some of the rutted areas of the road, the vehicle would not go into high mode.

This past weekend, I was returning from a kayaking trip to the coast. The load consisted of 3 people, 3 kayaks, and a good amount of cold weather and camping gear. The total weight was probably 900-1000 pounds, maybe a bit more. On the return trip, the vehicle settled into "low" and would not raise even to "normal." Considering that the truck is set up to carry 4 people and 4 boats with gear, this was a major disappointment.

I realize that there is a stated weight limit for the system, and -- at least in the second case -- I *may* have exceeded that, but I still am a bit miffed about the whole thing. I guess I expected there to be a bit more "overbuiltness" in this vehicle given its heritage and reputation. This is supposed to be Toyota's flagship offroad adventure vehicle. How much adventure can I have if I can't even get 4 people and 4 boats somewhere to paddle?

I'm not going to whine and bitch about it , but if there are any would-be buyers reading this -- consider your use before you buy AHC and give yourself a good margin of error in doing so.

 

[hkeller]

What year and how many miles on your LC? This does not sound normal. I had trouble with my system in the past, which was repaired by Lexus. Sinces the, I've had the truck full of gear, stuff on the roof, and a hitch packer full of fire wood on the back. On occasion, i had to get everybody out of the car and close the doors to raise it to High. But that was when I had probably close to a couple thousand pounds of stuff in it. After it got to high, it never leaked down.

I wonder whether your sphere are low and putting extra stress on the system.

 

[twstrchasr]

Man, that's kind of surprising. I could see if you had really loaded it up, but I would think there should be a fair amount of leeway built into the system. Just wait till your Nav system goes out on ya once you are just out of warranty (like mine did)! You will be a little more than just miffed !!

 

[hedydd]

I often have this 'problem'. Ignore it if you can and let the bottom scrape a bit and pick a route that is easier rather that more harder IYSWIM.

This problem is at its worse when I have something on the drawbar jaw with a vertical load rather more than recomended A ten cube rotary muck spreader for instance o-) Empty of course.

 

[Jim_Chow]

Sounds a little low. The stock system should hold ~1200 lbs (maybe less if going up a big hill?) for passengers+gear. If your 3rd row seats are still in, they are like 100 lbs. If you have aftermarket bumpers, etc., that only subtracts from the max load. I've only put about 700 lbs in mine w/o issues running in N. When I ran it on H going uphill, I only was day trippin', so I had less gear. Are your boats on a trailer or on the roof? If on a trailer, maybe there's too much tongue weight?

 

[ycookmd]

Thanks for the replies.

The kayaks are carried on a roof rack. They are maybe 50-60 pounds a piece. Inside gear is always loaded with the weight centered over the rear axle rather than towards the tailgate.

I have 2006 with 38K miles. I have the extended Platinum warranty, though. I might take it in and have the dealer run a diagnostic whatever on it and see if anything comes up. It seems to work fine when it's not heavily loaded.

 

[uzj100]

Sounds like a warranty issue.

 

[ats4x4dotcom]

I'd advise new purchasers to steer away from AHC.

900-1000 pounds, maybe a bit more. I realize that there is a stated weight limit for the system, and -- at least in the second case -- I *may* have exceeded that, but I still am a bit miffed about the whole thing. I guess I expected there to be a bit more "overbuiltness" in this vehicle given its heritage and reputation. This is supposed to be Toyota's flagship offroad adventure vehicle. How much adventure can I have if I can't even get 4 people and 4 boats somewhere to paddle?

I'm not going to whine and bitch about it , but if there are any would-be buyers reading this -- consider your use before you buy AHC and give yourself a good margin of error in doing so.

The load carrying is 270kg or 594lb, so because you bought a vehicle with this feature, and it wont exceed that limit, you have a problem with it?

Just add heavier coils, and keep the hyd system within its range loaded, and the problem you created is solved.

its not rocket surgery, and certainly no fault of the manufacturer, that i can see, unless they held a gun to your head to make you buy AHC without researching it.,......

 

[ycookmd]

The load carrying is 270kg or 594lb, so because you bought a vehicle with this feature, and it wont exceed that limit, you have a problem with it?

Just add heavier coils, and keep the hyd system within its range loaded, and the problem you created is solved.

its not rocket surgery, and certainly no fault of the manufacturer, that i can see, unless they held a gun to your head to make you buy AHC without researching it.,......

Page 246 of the manual states that the total load capacity is 545 KILOS. That's 1200 POUNDS (2.2 pounds per kilo). My estimated load was just at or under that.

If you feel the need to write a smart-ass reply, get your facts straight first.

 

[cpcc]

Now, Now Mudders, lets play nice.

 

[ats4x4dotcom]

Page 246 of the manual states that the total load capacity is 545 KILOS. That's 1200 POUNDS (2.2 pounds per kilo). My estimated load was just at or under that.

If you feel the need to write a smart-ass reply, get your facts straight first.

I have, and its not a smart ass reply, its the truth, do research before purchasing, and dont expect the world to bend to what you "think" it should do, and you wont have issues, simple really.

Now, back to the "its not rocket surgery" mathmatics, divide 545 x 2 and you get the axle load the suspension will lift each end, not total at one end.........

Works out 270 does it?



I thought so......



So, if you had more than 270kg one end, it does what you described, because it exceeds the manufacturers specification, put firmer springs in to get the suspension back to lifting no more than 270kg, and you have the problem solved, or do some research, and buy a standard truck that suits your requirement......

 

[ycookmd]

I have, and its not a smart ass reply, its the truth, do research before purchasing, and dont expect the world to bend to what you "think" it should do, and you wont have issues, simple really.

Now, back to the "its not rocket surgery" mathmatics, divide 545 x 2 and you get the axle load the suspension will lift each end, not total at one end.........

Works out 270 does it?

I thought so......

So, if you had more than 270kg one end, it does what you described, because it exceeds the manufacturers specification, put firmer springs in to get the suspension back to lifting no more than 270kg, and you have the problem solved, or do some research, and buy a standard truck that suits your requirement......

That makes no sense at all. Either you honestly mistaken, or you are just attempting to cover your mistake.

The stated load carrying capacity of the vehicle is not supposed to be divided in two and separated between the axles. If I'm not mistaken, the passenger and cargo areas lie behind the front axle. Generally speaking, your passengers and cargo fit into those areas. I doubt the Toyota engineers expected people to read the manual, and then take half their passengers and cargo and strap them over the hood.

Like the helpful posts before you came along suggested, I'm going to take it in and see if it's a warranty issue.

If it's not a system failure, I stand by my opinion that the AHC is a bit of a disappointment. 1200 pounds comes to 300 pounds per person for a full load of 4 with outdoor gear, which is what I estimated when I purchased the vehicle. When I researched the purchase (which I did thoroughly), that sounded reasonable. As always in life, hindsight provides a clearer picture.

The point of my post was to enlighten new purchasers with what I learned. Though it sounded right initially, that load capacity doesn't leave much of a margin, especially for long trips with 4 people. It also doesn't allow any margin for unanticipated uses (for example, I didn't have the deer lease at the time of the purchase). If the limit is 1200 pounds, and there is no "over-engineering" then I'd advise new purchasers to steer away from the AHC system, or heavily overestimate their needs before they buy.

 

[ShottsUZJ100]

That makes no sense at all. Either you honestly mistaken, or you are just attempting to cover your mistake.

The stated load carrying capacity of the vehicle is not supposed to be divided in two and separated between the axles. If I'm not mistaken, the passenger and cargo areas lie behind the front axle. Generally speaking, your passengers and cargo fit into those areas. I doubt the Toyota engineers expected people to read the manual, and then take half their passengers and cargo and strap them over the hood.

Like the helpful posts before you came along suggested, I'm going to take it in and see if it's a warranty issue.

If it's not a system failure, I stand by my opinion that the AHC is a bit of a disappointment. 1200 pounds comes to 300 pounds per person for a full load of 4 with outdoor gear, which is what I estimated when I purchased the vehicle. When I researched the purchase (which I did thoroughly), that sounded reasonable. As always in life, hindsight provides a clearer picture.

The point of my post was to enlighten new purchasers with what I learned. Though it sounded right initially, that load capacity doesn't leave much of a margin, especially for long trips with 4 people. It also doesn't allow any margin for unanticipated uses (for example, I didn't have the deer lease at the time of the purchase). If the limit is 1200 pounds, and there is no "over-engineering" then I'd advise new purchasers to steer away from the AHC system, or heavily overestimate their needs before they buy.

Don't let him bug you. He knows everything.

His math of 594 pounds would make it far and away the record low for even a Wrangler let alone an 8-passanger SUV. Two potbellies like me and a suitcase and you're at capacity.

Payload for my 2001 was 1745 lbs. You telling me the Lexus version drops it to 594?

I still have not seen any pics from this guy where his suspensions out-flex mine! Come on Darren......where's the pics? Beat this. (And I hope you actually can because any improvement is credible) Come on Darren.....no body lift here. This is a 100% bolt-on suspension.

Sorry for the hijack. I just get tired of this guy's holier (intentionaly mis-spelled) than thou attitude with nothing to back it up.

 

[twstrchasr]

holier ----You are correct. Doesn't look right though, does it?

 

[ats4x4dotcom]

That makes no sense at all. Either you honestly mistaken, or you are just attempting to cover your mistake.

The stated load carrying capacity of the vehicle is not supposed to be divided in two and separated between the axles. If I'm not mistaken, the passenger and cargo areas lie behind the front axle. Generally speaking, your passengers and cargo fit into those areas. I doubt the Toyota engineers expected people to read the manual, and then take half their passengers and cargo and strap them over the hood.

Like the helpful posts before you came along suggested, I'm going to take it in and see if it's a warranty issue.

If it's not a system failure, I stand by my opinion that the AHC is a bit of a disappointment. 1200 pounds comes to 300 pounds per person for a full load of 4 with outdoor gear, which is what I estimated when I purchased the vehicle. When I researched the purchase (which I did thoroughly), that sounded reasonable. As always in life, hindsight provides a clearer picture.

The point of my post was to enlighten new purchasers with what I learned. Though it sounded right initially, that load capacity doesn't leave much of a margin, especially for long trips with 4 people. It also doesn't allow any margin for unanticipated uses (for example, I didn't have the deer lease at the time of the purchase). If the limit is 1200 pounds, and there is no "over-engineering" then I'd advise new purchasers to steer away from the AHC system, or heavily overestimate their needs before they buy.

Well, I can tell you its designed to lift 270kg, and when its heavier than that it goes to low setting. Wether you believe it or not, is up to you, given its your truck, but we modify the AHC and suspension on these models all the time, as well as doing suspension lifts on them, and we need to know the facts, to get the hyd pressures correct with the load required to carry, so no lifting doesnt happen.

The fact we can do this, and get it right, and not complain about it says to me, we may just have a little more idea about it than you, even after researching your purchase.

Change the rear springs to something more suitable, and your problem will be solved.

 

[siglo]

ats4x4dotcom is right, I've had the same problem with my AHC and it was straight forward to solve. I bought my 100 brand new and during the first couple of months I loaded it with some gardening supplies (fertilizer, sand, etc). The weight was way less than 500KGs and I was very surprised to see the 100 drop to the low position. The short answer solution is to install heavier springs and adjust the pressure back to the factory level.

I've experimented with all springs from OME and IIRC the 866 was the most balanced one on and off road. I've had a kaymar rear bumper and the long ranger combo tank at the time. After playing with the AHC system for a while, I decided to remove it completely. I do miss it sometimes especially during long highway travel, but my 100 performs much better without it off road now.

ShottsUZJ100, please stop posting the same pics over and over in every thread you venture into :shotts:

 

[pint]

This is good info, although disappointing. Looking at a newer LC or LX next spring for the wife. I was thinking one with AHC and I would take it over in a few years! If the AHC system can't handle some armor, as well as a reasonable load, I can't go that way. Just like ycookmd said in his original post...this may be good info for future buyers.

Is anyone running the stock AHC system with aftermarket (Slee/ARB/TJM) bumpers, a winch, oversized tires, drawers, etc?

 

[Texasoil]

LHC load capability

Remember that weight in the gas tank is part of the 'load capacity.' A full tank of 40 gal is some 250#Toyota is very conservative in all their operating stress/load considerations.

If enough folks are interested, I can certainly design and offer a modest cost 'fix' that will increase the load carrying capacity of the AHC system. Hell, I can even make it user adjustable!

Note however installation will probably void warranty on load related issues and heavier loads will negatively impact stopping distance, handling stability, emergency situation roll-over resistance. Can't ignore physics and gravity. :whoops:

 

[dclee]

Is anyone running the stock AHC system with aftermarket (Slee/ARB/TJM) bumpers, a winch, oversized tires, drawers, etc?

Lots of Lexus owners, including Christo Slee. But as Darren mentions, they do have to modify the suspension to compensate. In Christo's case, he also reset the system so that he could override the automatic raise/lower behavior under different conditions. Should be lots of posts on MUD about his build.

 

[dclee]

That makes no sense at all. Either you honestly mistaken, or you are just attempting to cover your mistake.

Just a heads up, ats4x4dotcom has probably forgotten more about Cruisers, off-roading, and vehicle dynamics than most of us will ever know. I know you don't have the context yet, but give some thought to what he says. Not that Darren needs me to speak up for him, but he has a lot of good knowledge that you can benefit from by reading his posts on MUD, so don't throw away a good resource.

BTW, the idea of splitting load evenly between axles is not a new one. It's kind of a common sense thing, actually. Also, I don't have AHC, but even in my 2004 owner's manual Toyota does say to "Be careful to keep the vehicle balanced. Locating the weight as far forward as possible helps maintain the balance." Also remember that axles are load rated. Each has a separate load rating independent of the other axle. That's why weigh stations don't just weigh the entire weight of a vehicle over four tires, but individually at each axle. That difference does matter.

Anyway, I'd be interested to see what Lexus says about this. It should be fairly easy for them to test the hydraulics on the AHC system and see if they are at factory spec (which I suspect they are). But let us know either way, that would be good info to share.

My $0.02,