I replaced them in my garage with OEM accumulators from Japan via eBay
LX570 AHC “Basics” - Added as sticky thread for AHC Issues (3 Viewers)
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Awesome. Did that help the ride quality? How many miles did you have when you did the swap? Do you remember how much it was for all 4 accumulators? I assume you used fresh AHC fluid too?
I read that globes make a difference, but I think replacing shocks is what needs to happen. Damping control is in the shock and probably give up over time. I looked briefly and shocks are 500 bucks all around and should be pretty easy to replace.
I'm not an expert, but i don't believe this is correct. Most of the damping is in the 4 accumulator globes and the rest is in smaller accumulators attached to the damping force control actuators that feed the shocks.
I"m interested in what the failure mode is for tired globes. With a typical suspension I would think it would be less dampening, since once the shock absorbers give what gas/fluid they have within the strut, there would be less there to dampen anything. The failure mode for the AHC accumulators is to be overfilled with fluid as the nitrogen in the bellows escapes over time. To me this would mean that AHC suspension actually fails in the opposite way, in that the suspension stiffens as it ages.
This has probably been brought up before, but I haven't seen a specific conversation about it. Am I correct in my assumptions above?
I've ordered the ebay accumulators and plan to replace soon. I feel like my suspension is too stiff and doesn't dampen smaller imperfections in the road well. So I'm hoping my reasoning above makes sense and replacing the accumulators is going to help.
Most of the damping is done at the remote damping force control actuator. Some damping is also done within the front shock absorber/hydraulic cylinder as there exists some traditional shim stack there that I've seen. I believe the rear shocks are mostly passive.
If the globes fail or become marginal, there won't be enough fluid volume passing through the connected damping force control actuator, resulting in the symptom of lost damping.
EDIT: @lx200inAR got to it first and I agree
Good stuff! I take it back, I misread the FSM. I though it was implying it was part of the shock which didn't make sense. That diagram and the cost of the shocks now all make a lot more sense.
Sounds like you and I are of the same mind. Are you planning on replacing the shocks as well, or just the accumulators?
Pressurized N2 bladders have a finite life due to degradation of the internal elastomers. Seeing as these are essentially in constant dynamic use it makes sense they’re a consumable item. Just when to replace them is up to the user. I imagine I’ll replace the 4 globes at 150k of on-road driving.
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I'm at 105k on mine and will replace as soon as I have time. Not planning to do shocks yet. I have the rear set, as the first mechanic I took it to decided I had a leaky rear drivers side shock, but then didn't want to replace once he saw how hard it was to get to that top nut. So now I have shocks on the shelf. If replacing them doesn't make much difference, then front/rear shocks will be next on the list. I ordered the LC200 front spacers and plan to install those when I change out the accumulators. But that's just so I can lift the front a little and maintain stock pressures.
My problem is that my LX (of which i've only put 5k miles on) is the only land cruiser/LX I've ever been in. So I have no idea what it is supposed to ride like. My ride isn't bad now, and I can tell a difference between the different modes, as far as how the suspension changes. But I also don't feel like it rides like a vehicle anyone who paid 90k for would be happy with. But I may just be nitpicking, it is still a box sitting on top of a truck frame.
My problem is that my LX (of which i've only put 5k miles on) is the only land cruiser/LX I've ever been in. So I have no idea what it is supposed to ride like. My ride isn't bad now, and I can tell a difference between the different modes, as far as how the suspension changes. But I also don't feel like it rides like a vehicle anyone who paid 90k for would be happy with. But I may just be nitpicking, it is still a box sitting on top of a truck frame.
I agree and maybe part of are 20 inch wheels. It's an ok ride, but this is a body on frame truck with solid rear axle... I think the ride is a bit harsh but not terrible. I does corner pretty flat if you can hold being up in the sky. Mine has 135k miles and I use it A LOT. 20k miles this year mostly towing to race tracks and to FL. AHC is awesome for loading race car on the trailer.
I bought the truck at 98k miles:
- AHC fluid flush shortly after purchase. Mild ride improvement but much less time to raise up to high.
- Replaced all 4 shocks due to leaks ~ 115k miles. Shocks were cheap, maybe $500. No change in ride quality before or after.
- Replaced all 4 low pressure accumulators and fluid at ~130k miles. Substantial improvement in ride quality.
Is it a messy job to replace the globes? I assume you need to bleed afterwards?
Very little fluid comes out at the globe connections, and yes, full rebleed required after.
Thank you! I bought my 2011 with 97k miles and looks like my logic flows with what you experienced.
A couple questions for the crew:
TeCK's considerately provided figure shows the first gas chamber #2 for the fronts and the relief chamber (looks like a blow-off for rapid cycling). #2 looks like it controls dampening first, and #1 controls spring rate behind it.
So wouldn't you also want to replace the #2 chamber (or maybe do that first since it is doing a lot of work?)?
The parts list has the accumulator and the "accumulator subassembly" which looks like the relief gas chamber. Both are of course $500 usd.
The #1 in the rear also has an second cylinder accumulator, it is just cut off in the picture next to the globe.
So if the symptom is poor dampening are folks changing the correct part, or possibly the suspensions are so worn that even just the spring rate makes a discernible difference? I see from the mercedes with a similar system that they can see if the pressure globes have dropped, that corresponds to our tank level markings...sort of. (https://www.abcspecialist.nl/uploads/documents/active_body_control_uk_2019_watermark.pdf)
TeCK's considerately provided figure shows the first gas chamber #2 for the fronts and the relief chamber (looks like a blow-off for rapid cycling). #2 looks like it controls dampening first, and #1 controls spring rate behind it.
So wouldn't you also want to replace the #2 chamber (or maybe do that first since it is doing a lot of work?)?
The parts list has the accumulator and the "accumulator subassembly" which looks like the relief gas chamber. Both are of course $500 usd.
The #1 in the rear also has an second cylinder accumulator, it is just cut off in the picture next to the globe.
So if the symptom is poor dampening are folks changing the correct part, or possibly the suspensions are so worn that even just the spring rate makes a discernible difference? I see from the mercedes with a similar system that they can see if the pressure globes have dropped, that corresponds to our tank level markings...sort of. (https://www.abcspecialist.nl/uploads/documents/active_body_control_uk_2019_watermark.pdf)
One controls fine motion and one gross motion. Most of the damping we can perceive is to the gross motion.
teejnut
SILVER Star
Can we conclude there's no benefit of changing out the shock unless it's leaking?
Yes
Also, the chamber #2 is a much more robust contraption with a metal bellows rather than the elastomer one of chamber #1.
