Long Travel AHC (2 Viewers)

[Killacaviar]

Added more notes as to why in the write-up above here - Long Travel AHC - https://forum.ih8mud.com/threads/long-travel-ahc.1287237/post-14493235



Wondering if that is the limiting experience you're looking to improve on?

Awesome, certainly brings some
clarity to my situation. My lack of droop is certainly the major issue. Even in N with a sensor lift it’s not doing it.
This all seems really easy to do and above anything…affordable. I just ordered a few of the items last night and I’ll get going on this in July. At this point if I can get 1.5-2in of added droop in H it won’t be useless. As for the higher speed stuff I enjoy so much, N is just fine and the 35s already give me enough clearance for those situations the added droop there would a major change.

At this point based on the time/effort and price it would be foolish to not try.

I may add a tundra front end into the equation as well, simply to allow an easier transition to conventional coilovers if this doesn’t fit the bill.

Question: with the longer front studs and ahc line connection modification, do you think stacking two10mm OEM LC spacers would add any value to the setup? Or be doable at all?

 

[grinchy]

Excellent resource and work @TeCKis300.
I don’t love sensor lift, would the front spacers allow it to be set to default of even less than default levels?

 

[TeCKis300]

Awesome, certainly brings some
clarity to my situation. My lack of droop is certainly the major issue. Even in N with a sensor lift it’s not doing it.
This all seems really easy to do and above anything…affordable. I just ordered a few of the items last night and I’ll get going on this in July. At this point if I can get 1.5-2in of added droop in H it won’t be useless. As for the higher speed stuff I enjoy so much, N is just fine and the 35s already give me enough clearance for those situations the added droop there would a major change.

At this point based on the time/effort and price it would be foolish to not try.

I may add a tundra front end into the equation as well, simply to allow an easier transition to conventional coilovers if this doesn’t fit the bill.

Question: with the longer front studs and ahc line connection modification, do you think stacking two10mm OEM LC spacers would add any value to the setup? Or be doable at all?

Great point on price. $1400 in parts is chump change compared to aftermarket systems . Of course, the added labor, but IMO, the end results would be hard to beat.

Definitely this strategy can be expanded upon. And taken further with Tundra long arm. That should see something like +3" travel up front. I'm still trying to keep some daily balance and MPG efficiency in my setup, but that would be awesome for the right rig!

I see no issue stacking 2x LC (20mm total) spacers and the studs I used can accommodate that. You might be able to find a single Tundra spacer of the right thickness, and possibly even avoid the need to change studs. Most Tundra spacers are a bit too tall. You'll just have to watch the bump stops, and maybe space them down a bit so the front shocks don't become the hard compression limiter.

Here's what mine look like at the moment. Enough extra stud length. AHC line still has come clearance.

Couple other notes:
- Watch the brake line length and you may need extended ones. I have extended Tundra lines as part of my BBK upgrade
- I think you mentioned that your bump travel in AHC high felt really firm. That may be the accumulators/globes being worn out. Might consider fresh globes as part of this upgrade.

 

[TeCKis300]

Excellent resource and work @TeCKis300.
I don’t love sensor lift, would the front spacers allow it to be set to default of even less than default levels?

Curious why you don't love the sensor lift? Definitely a balance between useful sensor lift, and too much given stock travel. The 100-series guys have a rule of thumb to keep ~2.5" droop travel when sensor lifting.

I'll need to touch on this in the write-up, but there is the impact of AHC pressures. It should be done holistically.

The front spacers would pre-load the coil springs at normal ride heights. So some lift would bring neutral pressure back inline. This would need to be considered with the amount of added weight in any aftermarket armor, etc.

At the rear, in contrast, this does not change coil preload. That has to be separately handled at the coil spring. Again, need to look at it holistically between sensor lift, added weight, and max payload situations. No reason all of it can't be optimized which is my goal as I still need it to handle 2k payload between my 1200lb tongue weight trailer, aux tank, and people/gear. My solution for a 1" rear sensor lift is 30mm of coil spacer, and air-bags to have adjustability for more extreme loads.

 

[grinchy]

Curious why you don't love the sensor lift?

As I understand it (which is dimly), it flat out steals droop. Since H mode also uses droop, sensor lift exacerbates the situation you describe with potentially not enough droop.
I guess in my beginner suspension 'goals', I'd want N and H (and H+) to both have more than plenty droop, and both be in 'middle' of the full suspension stroke territory.
I also want the COG to be as low as possible for the situation. In my mind this is the real 'win' for AHC, we only need to run compromising levels of lift when it serves some other useful utility (crawling or whatnot).

 

[1UZJ80N60]

Did someone do thicker spacers with built in studs recently or did I imagine it? I believe that person also had to grind down the AHC brackets. How much more travel do the shocks have in them

Did someone do thicker spacers with built in studs recently or did I imagine it? I believe that person also had to grind down the AHC brackets. How much more travel do the shocks have in them?

Maybe that was one of my post you seen... I did use a 1.25" tundra spacer... and it was definitely pushing the limits as I had to notch the spring tower... I also had to clock the coil over which resulted in clocking the AHC hard line which resulted in leaving off one of the 4 stud bolts... I like what tecki300 is on to because of all 4 studs are being used.

 

[1UZJ80N60]

Rear Axle - 4.5 out of 5 banana job (fabrication and PITA to remove/install rear shock)​

Special tools: Long or offset 14mm box wrench , press, grinder or band saw, welder, lots of patience

Parts:
- New AHC rear shock
- AHC fluid

View attachment 3040870

The rear axle recipe is custom fabrication to extend the shock. As the rear motion ratio between shock and suspension travel is 1:1, it's about re-locating the lower eyelet by 1". 1" isn't really a magic number, but based on my assessment it was a reasonable balance between maximizing droop while still keeping the shock safe under full compression such that it doesn't take the full impact of being the first or primary bump limiter. I could see maybe expanding this to 1.5" for someone that's willing to be more aggressive or lower the frame bump stop accordingly.

I checked the witness marks and there seems to be lots of clearance potential, at least for my driving style, and airbags minimally at 5PSI.
View attachment 3040897


Easiest way in my mind was to lop off the partial eyelet on a new shock so it becomes a standoff bracket, take the harvested eyelet off the old shock, and burn them together. There potential to modify the axle side lower shock mount by relocating that higher, but I figured it was cheaper, easier, and reversible if I modified the shock.

Steps:
1) Depressurize AHC system by bleeding the rear accumulators. Bleed twice.
2) Remove AHC line from top of shock (2x 12mm bolts). This is going to be an exercise in patience.
3) Remove lower shock bolt
4) Remove sway bar link at top nut
5) Remove upper shock nut. More patience. Fortunately the LX shock piston is keyed. Unfortunately working from the inside of the frame with an boxed offset wrench turns only 30 degrees at a time.
6) Remove shock
7) Mark all components and note alignment and orientation. Dissemble coilover.
8) Press out lower bushing of both new and old shock
9) Cut full eyelet off old shock
10) Measure twice, and cut new shock eyelet to work as standoff to old eyelet hoop
11) Fabricate inner ring support with 1/4" steel
View attachment 3040900
12) Burn it all together, minimizing heat going into the shock body (undercut and need another cover pass here)
View attachment 3040901
13) Spray paint
14) Press new bushing in
15) Reinstall
16) Check brake line length, may need to bend some locating brackets to get more slack
18) Optionally shim frame bump stop down (I used a 1/4" shim). I may remove these as I shake things down, to maximize travel.
View attachment 3040898
19) Optionally shim sway bar end link down 1/4"

Rear Axle - 4.5 out of 5 banana job (fabrication and PITA to remove/install rear shock)​

Special tools: Long or offset 14mm box wrench , press, grinder or band saw, welder, lots of patience

Parts:
- New AHC rear shock
- AHC fluid

View attachment 3040870

The rear axle recipe is custom fabrication to extend the shock. As the rear motion ratio between shock and suspension travel is 1:1, it's about re-locating the lower eyelet by 1". 1" isn't really a magic number, but based on my assessment it was a reasonable balance between maximizing droop while still keeping the shock safe under full compression such that it doesn't take the full impact of being the first or primary bump limiter. I could see maybe expanding this to 1.5" for someone that's willing to be more aggressive or lower the frame bump stop accordingly.

I checked the witness marks and there seems to be lots of clearance potential, at least for my driving style, and airbags minimally at 5PSI.
View attachment 3040897


Easiest way in my mind was to lop off the partial eyelet on a new shock so it becomes a standoff bracket, take the harvested eyelet off the old shock, and burn them together. There potential to modify the axle side lower shock mount by relocating that higher, but I figured it was cheaper, easier, and reversible if I modified the shock.

Steps:
1) Depressurize AHC system by bleeding the rear accumulators. Bleed twice.
2) Remove AHC line from top of shock (2x 12mm bolts). This is going to be an exercise in patience.
3) Remove lower shock bolt
4) Remove sway bar link at top nut
5) Remove upper shock nut. More patience. Fortunately the LX shock piston is keyed. Unfortunately working from the inside of the frame with an boxed offset wrench turns only 30 degrees at a time.
6) Remove shock
7) Mark all components and note alignment and orientation. Dissemble coilover.
8) Press out lower bushing of both new and old shock
9) Cut full eyelet off old shock
10) Measure twice, and cut new shock eyelet to work as standoff to old eyelet hoop
11) Fabricate inner ring support with 1/4" steel
View attachment 3040900
12) Burn it all together, minimizing heat going into the shock body (undercut and need another cover pass here)
View attachment 3040901
13) Spray paint
14) Press new bushing in
15) Reinstall
16) Check brake line length, may need to bend some locating brackets to get more slack
18) Optionally shim frame bump stop down (I used a 1/4" shim). I may remove these as I shake things down, to maximize travel.
View attachment 3040898
19) Optionally shim sway bar end link down 1/4"

Wondering why you didn't go woth this design...it allows gains you 2 in of droop amd allows you to cut 2in of bottom of shock mount for better clearance....that is unless you did and did yourshock mod in conjunction woth that design?...it I've still yet to do my rear.... but hoping to in the next couple weeks before coal mine classic on July 14. Regardless good work buddy... way to push the envelope!!!

 

[TeCKis300]

Wondering why you didn't go woth this design...it allows gains you 2 in of droop amd allows you to cut 2in of bottom of shock mount for better clearance....that is unless you did and did yourshock mod in conjunction woth that design?...it I've still yet to do my rear.... but hoping to in the next couple weeks before coal mine classic on July 14. Regardless good work buddy... way to push the envelope!!!

I was really considering this strategy. Agreed it has the benefit of creating even more clearance under the axle.

It came down to a few things
- wanting to maximize suspension travel and I'm not sure that there would be enough room at full compression to still stuff the tires
- modding the shock was easier than working on the axle
- fully reversible modifying a $75 part (x2)

Still think it could be a great idea for the right rig.

 

[NKP Garage]

Great work so far. Following closely to see how your process goes.

 

[TeCKis300]

Liking it! Did you happen to measure front shock length at full compression?

I'll be doing a more thorough write-up and cut the shock apart in the near future. But here's some key dimensions.

Measuring from center of eyelet to shoulder of shock piston
Compressed - 18.75"
Extended - 24.5"
Piston diameter - 30mm

 

[TeCKis300]

Got her out on the dirt this past weekend for a couple days of slogging. Happy to report, the setup did great.

Heartbreak Ridge in Big Bear rated intermediate to difficult with rock gardens and ruts. But there were lots of optional lines to flex and test, and the long travel mod really took the rig to the next level. Both clearance with the additional sensor lift and a added flexiness / articulation at the higher positions. Honestly, nothing particularly tested the rig and it was easy street. Not even close to dragging any bumpers or underbody with the added sensor lift putting the chassis at almost 7" total lift.

I didn't get any good media on the harder stuff as the rest of the group was too busy coping and dragging. This section might as well be a mall parking lot.

 

[tbisaacs]

Money shot. The extra droop is really apparent. It’s almost like you have KDSS.

I Know heavy bumpers are against the ethos of this build, but man, This thing would be a monster without all the tupperware in the back.

 

[Killacaviar]

I’m knocking out a new steering rack at the moment. Your process is next on the list after l’m Baselined. I’ll be doing a whole flush and glove replacement as well. Looks great man. The descriptions alone in your post prove to me this could be my problem Solver. I have had my LX on 3 wheels too many times to count at this point… can’t wait.

 

[NKP Garage]

Got her out on the dirt this past weekend for a couple days of slogging. Happy to report, the setup did great.

Heartbreak Ridge in Big Bear rated intermediate to difficult with rock gardens and ruts. But there were lots of optional lines to flex and test, and the long travel mod really took the rig to the next level. Both clearance with the additional sensor lift and a added flexiness / articulation at the higher positions. Honestly, nothing particularly tested the rig and it was easy street. Not even close to dragging any bumpers or underbody with the added sensor lift putting the chassis at almost 7" total lift.

I didn't get any good media on the harder stuff as the rest of the group was too busy coping and dragging. This section might as well be a mall parking lot.

Looks like it did pretty darn well!!

 

[TeCKis300]

View attachment 3058494

Money shot. The extra droop is really apparent. It’s almost like you have KDSS.

I Know heavy bumpers are against the ethos of this build, but man, This thing would be a monster without all the tupperware in the back.

I don't believe AHC gives up articulation to KDSS. At least stock for stock. Maybe to your point, most every enthusiast LC suspension is not stock with the benefit of longer droop travel. Not from KDSS, but from the longer aftermarket shocks. Which is the reason for this mod to break through that previous limitation.

As for armor, as much as I'd like to build the car in that image, the reality is that it doesn't add capability. Too much weight decreases performance, sometimes substantially. Until the bumpers touch down of course, and where it does earn it's value. I was going to cut the rear bumper and fabricate tube sliders. With the added sensor lift, the reality is that there's so much clearance and breakover, I'm not close to touching down even in difficult rated trails. Until I go beyond that, then maybe revisit the idea.

 

[linuxgod]

I don't believe AHC gives up articulation to KDSS. At least stock for stock. Maybe to your point, most every enthusiast LC suspension is not stock with the benefit of longer droop travel. Not from KDSS, but from the longer aftermarket shocks. Which is the reason for this mod to break through that previous limitation.

As for armor, as much as I'd like to build the car in that image, the reality is that it doesn't add capability. Too much weight decreases performance, sometimes substantially. Until the bumpers touch down of course, and where it does earn it's value. I was going to cut the rear bumper and fabricate tube sliders. With the added sensor lift, the reality is that there's so much clearance and breakover, I'm not close to touching down even in difficult rated trails. Until I go beyond that, then maybe revisit the idea.

Go run Fins N Things in Moab and get back to me on whether you still don't need a rear tube bumper. (Or something harder even). I'll be you a hot trail lunch you change your mind then

For your normal trail use though I suspect you're right, you really don't need the extra protection with all the lift you've got. Moab last year really changed my build plans for me.

 

[TeCKis300]

Go run Fins N Things in Moab and get back to me on whether you still don't need a rear tube bumper. (Or something harder even). I'll be you a hot trail lunch you change your mind then

For your normal trail use though I suspect you're right, you really don't need the extra protection with all the lift you've got. Moab last year really changed my build plans for me.

Definitely got to get out there! It very well may change my mind (or force my hand) on the bumper. Mostly the rear corners though as we all know departure angle is often the first limitation with the 200-series geometry.

While on the topic, many steel bumpers may provide better height clearance, but just and many reduce approach and departure angles with how far they are projected past the stock body lines. Win some, loose some?

 

[GatorBait1551]

Definitely got to get out there! It very well may change my mind (or force my hand) on the bumper. Mostly the rear corners though as we all know departure angle is often the first limitation with the 200-series geometry.

While on the topic, many steel bumpers may provide better height clearance, but just and many reduce approach and departure angles with how far they are projected past the stock body lines. Win some, loose some?

Solve the problem of weight and clearance with a Dissent

Subd for more long travel AHC good work!

 

[outlaw4shrt]

Great job! Very inspiring.

 

[Killacaviar]

Stock Arms and AHC: roughly 11.3 inches of front travel and 12.5 inches in the back and a full 5l fluid flush. This thing drives better around town and flexes just as well as my old 2.5 king setup. Can’t wait to go play in the mountains this weekend.

I was all by my lonesome so I apologize for the “poser” shots with no one driving. But just wanted to check rubbing.

I’ll get some video and proper photos this weekend.