Anatomy of an AHC shock (2 Viewers)

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TeCKis300

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Fronts​

Measuring from center of eyelet to shoulder of shock piston
Compressed - 18.75"
Extended - 24.5"

Monotube. 5.75" travel. 30mm shaft with internal oil passage. 43.5mm piston. 54.5mm shock body.

Lower bushing - 16mm bolt hole, 53mm bushing shell

Has internal valving. ~11 element compression shim stack. ~9 element rebound stack. 1 large HD piston seal. 2 piece wiper seal.

Yellow/gold collar looks to be a droop stop bumper. Looks like there could be another 1"+ of travel if the stop collar were higher up.


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Missed some shims in this pic - reference here
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Rears​

Measuring from center of eyelet to shaft shoulder
Compressed - 17.75"
Extended - 26.25"

Monotube. 8.5" travel. 30mm shaft with internal oil passage. 45mm piston. 54mm shock body.

Lower bushing - 19mm bolt hole, 45mm bushing shell

Has internal valving. ~10 element compression shim stack. ~11 element rebound stack. 1 large HD piston seal. 2 piece wiper seal.

Yellow/gold collar looks to be a droop stop bumper. There's a tall ~.75" stop collar.

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Missed some shims in this pic - reference here
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Makes me want to tear into an LX600 AHC shock...
 
Finally got around to tearing this down eh? Thanks for sharing! While you are at it, can I ask for some measurements? Specifically the eyelet diameter at the bottom of the shock, and the cross sections on the metal outside the bottom mount bushings:

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Finally got around to tearing this down eh? Thanks for sharing! While you are at it, can I ask for some measurements? Specifically the eyelet diameter at the bottom of the shock, and the cross sections on the metal outside the bottom mount bushings:

View attachment 3275035

You got it. Added some bushing dimensions to the posts above.

For the dimensions you're looking for: 16mm bolt hole, lower shock eyelet outside dimensions: 66mm tall, 63mm wide.

Wondering what you're cooking up :)
 
You got it. Added some bushing dimensions to the posts above.

For the dimensions you're looking for: 16mm bolt hole, lower shock eyelet outside dimensions: 66mm tall, 63mm wide.

Wondering what you're cooking up :)
Toying with different designs for a LCA mount that will raise the lower bolt/eyelet mount...trying to come up with something "reversible" for an AHC lift on the front end. Many thanks for the measurements. It saves me having to try to disassemble. If you happen to possess an LX600 front shock, I would also be very interested in similar measurements.
 
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Way to go P!
This day was long time coming!

VV interesting the differences there front to rear... Any lip on the rear shock body that could catch a coil?
Im thinking rears up front? With a 19-16mm bushing for the eyelet bolt?

What are YOUUU cooking up???
 
I figured there had to be some damping built into the shock itself, with what the AHC system does augmenting that baseline control.

LX600 shocks are about 250 front and 650 rear. Rear appears to have an electronic component built into the shock per parts diagrams.
 
Now that you’ve seen them apart, is there a potential non-destructive path inside?

I’m interested in the washer thicknesses and order for the front vs rear shims stacks too.

Also I now know where my calipers ended up, just return those when you have a chance. No rush.
 
Dad really is crazy.
 
I figured there had to be some damping built into the shock itself, with what the AHC system does augmenting that baseline control.

LX600 shocks are about 250 front and 650 rear. Rear appears to have an electronic component built into the shock per parts diagrams.

Yea that confirms it. I wrongly assumed they were just dumb hydraulic rams.
 
Has this been posted up here yet? It appears that the AHC pump and accumulators and valving are responsible for dynamic spring rate changes (both static and dynamic) but doesn’t mention damping. This is also 300-specific and things have changed.

 
Has this been posted up here yet? It appears that the AHC pump and accumulators and valving are responsible for dynamic spring rate changes (both static and dynamic) but doesn’t mention damping. This is also 300-specific and things have changed.

Each corner has an 16-step adjustable damping valve. It's part of the mechanism where the accumulators attach. I believe that stayed the same between the 200 and 300.

There is a large document detailing the 200 series AHC/AVS from the FSM floating around.
 
Has this been posted up here yet? It appears that the AHC pump and accumulators and valving are responsible for dynamic spring rate changes (both static and dynamic) but doesn’t mention damping. This is also 300-specific and things have changed.

Interesting.. that diagram doesn't show the actuators mounted on the rear shocks on some LX600s. Toyota denotes those as F-sport and "AVS".. @TeCKis300 wasn't that the name of the system on 200-series AHC? Or was that AVSS?
 
So are yall thinking to restrict the internal valving or something? Also aren’t these internal bypass channel valve shims interchangeable? So one could do the reverse…

@bloc’s comment had me wondering a bit. You are essentially thinking of trying to impede the internal damper correct?

I believe increasing the fluid viscosity might accomplish the same effect. Yall will know much more than i do here.
 
Are there fluid volume limitations in the system? In other words adding stroke would imply adding fluid, but can the system handle the excess?
 
Interesting.. that diagram doesn't show the actuators mounted on the rear shocks on some LX600s. Toyota denotes those as F-sport and "AVS".. @TeCKis300 wasn't that the name of the system on 200-series AHC? Or was that AVSS?
AVS is the vairiable valving. It’s all integrated, but AHC is the lift part and AVS is the vairiable damping control/high spring rate part. It was called this on the 200 as well.

Someone already bought a lx600 rear shock I believe. They didn’t mention the price being crazy high. Are you sure the shock you are looking at is the AHC shock and not the standard suspension one. Or I guess possibly some crazier F-sport version.
 
Are there fluid volume limitations in the system? In other words adding stroke would imply adding fluid, but can the system handle the excess?
Based on measurements above it would take about a 3rd of a liter to move all 4 corners 2” (based on the 45mm piston listed above).
 

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