Using stock lx470 torsion bars with ome shocks (1 Viewer)

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Was looking into getting a old man emu set for my lx470 as I have no interest in trying to fix the ahc .
My question is why does everybody reccomend you must replace the torsion bars on lx470 if getting rid of the ahc. I've read that some people switch to the landcruiser oem tbars on the lx and work with that and lots of people leave the stock torsion bars on the Toyota model and add new shocks and springs without issues.

I'm not looking to create an off-roading beast just want the most simple best regular suspension setup for my lx 470 as I noticed one shock has leakage around it.

Previous owner said the ahc was removed but I have no way of determining that either perhaps some people on here could help. The truck rides pretty high currently. I drove beside another lx470 on the weekend and that thing appeared to be very low it's ahc must have been stuck on low or maybe my truck actually does have the ahc removed. I added 18" trd pro rims without any rubbing at and the truck looks incredible.
 
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Here is couple pics

IMG_3820.JPG


IMG_3821.JPG
 

ga12r1

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Was looking into getting a old man emu set for my lx470 as I have no interest in trying to fix the ahc .
My question is why does everybody reccomend you must replace the torsion bars on lx470 if getting rid of the ahc. I've read that some people switch to the landcruiser oem tbars on the lx and work with that and lots of people leave the stock torsion bars on the Toyota model and add new shocks and springs without issues.

I'm not looking to create an off-roading beast just want the most simple best regular suspension setup for my lx 470 as I noticed one shock has leakage around it.

Previous owner said the ahc was removed but I have no way of determining that either perhaps some people on here could help. The truck rides pretty high currently. I drove beside another lx470 on the weekend and that thing appeared to be very low it's ahc must have been stuck on low or maybe my truck actually does have the ahc removed. I added 18" trd pro rims without any rubbing at and the truck looks incredible.
You need to use regular TLC torsion bars or ome, Iron Man, Etc because the LX bars are not strong enough to support the weight of the cruiser without the supplemental help of the ahc “shocks” (they’re not shocks at all). The ahc system supplements the static torsion bars, and makes the ride height and comfort level adjustable.
 
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Do you really think they are not as strong ?
From an engineering standpoint one would think the torsion bars on the suspension that goes up and down would be engineered to be stronger ?
 
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There is many people who have been driving on blown ahc systems so would the lx stock suspension not pickup the weight of the lx470 which is probably heavier than a landcruiser?
 
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YardPig

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You need to use regular TLC torsion bars or ome, Iron Man, Etc because the LX bars are not strong enough to support the weight of the cruiser without the supplemental help of the ahc “shocks” (they’re not shocks at all). The ahc system supplements the static torsion bars, and makes the ride height and comfort level adjustable.

He is correct, the stock AHC TB's will be too thin for a lifted application. I would recommend LC stock torsions for nice ride quality if you don't plan to start pounding on the weight or OME torsions if you don't mind it stiff. I went with stock torsions on my LC with Toyota shocks and 860 OME rear springs and am very happy with the ride quality even with an ARB up front.

Here are some specs from another mud member thread;

Non-ACH TBs are 28.87mm, which is about 1.1 inches, while the ACH TBs are 25.5 mm, which is 1.01 inches.
 
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Thank you this was the response I was looking for. 3mm difference in thickness doesn't seem like a lot but probably is.

The shipping on the torsion bars from USA is very expensive .
Wonder if anybody in Canada has any for sale ?
 

YardPig

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Finding a 100 LC in Canada is not an easy exercise, especially one being parted out.

I would maybe post on the MUD wanted classifieds for some used LC torsions. Shipping shouldn't be too bad.
 

BEG

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You could technically crank the LX torsion bars, even re-index them if necessary, to get the LX up to the right height. However, the spring rate of the LX bars will never be right.
 
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Thank you this was the response I was looking for. 3mm difference in thickness doesn't seem like a lot but probably is.
Correct, when talking torsion bars thickness matters. If left fitted without the hydraulics you may be able to reindex and torque AHC bars to get something resembling a normal height whilst parked but you need to consider how safely those stressed bars are going to perform when the vehicle is fully loaded at speed, cornering etc.

From a previous post.

“The question as to the adequacy of AHC (25.5mm) torsion bars being left in service after the AHC system has been gutted, instead of replacing them with the correctly rated bars (28.8mm) - or heavier if going aftermarket - often comes up. Here's some fun facts regarding the engineering behind torsion bars. All else being equal if you double the thickness of a torsion bar you increase its rate by 16 times so that extra 3+mm in diameter the conventional torsion bar has over the AHC bar provides significantly more effective torsional force - about 60% more actually. You can go to a site such as swayaway.com and in their Tech Room they have a cool TB rate calculator. Using conventional LC bars at 1.13in v AHC bars at 1.0inch (bar length and lever arm lengths are arbitrary as we're just looking at ratios) you'll see that the thicker bar provides approx. 60% more effective torsional rate at the front wheel. Working on the premise that Toyota's design engineers had big brains, plenty of time and billions of yen I'd like to believe they chose torsion bars appropriately rated for their respective applications. Accordingly anyone who seriously believes they can just reindex underrated AHC bars in a non AHC application and safely get away with it in the long term will ultimately be disappointed.”
 
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Q: is there any advantage to replacing the stock LX TB with the thicker LC TB while still keeping the functional AHC? Is more better in this case?
When my AHC fails I do plan to go OME or the like. So wondering if I do the TB now would I benefit while overlanding etc?
 

BEG

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Q: is there any advantage to replacing the stock LX TB with the thicker LC TB while still keeping the functional AHC? Is more better in this case?
When my AHC fails I do plan to go OME or the like. So wondering if I do the TB now would I benefit while overlanding etc?
The suspension is a system that all needs to work in unison for best results. If you increase the spring rate, you would have to increase the weight in order for the spring to do its job. If you increase the weight, you have to adjust the damping accordingly. The AHC is a very adaptable system that has a damping range that it can operate within. It could potentially work at the top of its range with the LC bars but you'd have a rough ride if you're not heavily loaded up.

Personally, I'd love to get some LC bars turned down to 27mm but I haven't had any luck getting responses from suspension companies willing to do so. I think that would be the perfect rate for an offroad/overland setup (combined with some heavier rear springs) with armor and camping gear.
 
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Ok so you are seeking the Goldilocks zone..
TBH I'm happy with the AHC for what I do. I'm anticipating changing out the wear items and looking to understand what I need to swap out and what I need to upgrade. Wonder if there's a comprehensive LX suspension guide.....
 

BEG

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Ok so you are seeking the Goldilocks zone..
TBH I'm happy with the AHC for what I do. I'm anticipating changing out the wear items and looking to understand what I need to swap out and what I need to upgrade. Wonder if there's a comprehensive LX suspension guide.....
There is a thread called "Definitive list of AHC maintenance items." It's about as comprehensive as it gets.
 

bamabrock

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Ok so you are seeking the Goldilocks zone..
TBH I'm happy with the AHC for what I do. I'm anticipating changing out the wear items and looking to understand what I need to swap out and what I need to upgrade. Wonder if there's a comprehensive LX suspension guide.....
 

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