Topic: Independently controlled air shocks supplementing rear suspension?

[a1gemmel]

I have an idea, wondering if anyone has done it before.

I'm thinking of adding a second set of shock mounts to the rear axle (leaf springs, rancho shocks existing) to run a pair of air shocks, the kind that you can inflate and deflate.
Then I'd wire a panel to inflate and deflate either side independently.
I have a few reasons for wanting this:
- load assist while towing
- level the truck on uneven ground for sleeping in the bed
- counter off-camber situations by maxing out the downhill shock

Is that last point even feasible? Would that work?
Anyone used air shocks on a crawler with leaf springs before?

[Gnarly4X]

I have an idea, wondering if anyone has done it before.

I'm thinking of adding a second set of shock mounts to the rear axle (leaf springs, rancho shocks existing) to run a pair of air shocks, the kind that you can inflate and deflate.
Then I'd wire a panel to inflate and deflate either side independently.
I have a few reasons for wanting this:
- load assist while towing
- level the truck on uneven ground for sleeping in the bed
- counter off-camber situations by maxing out the downhill shock

Is that last point even feasible? Would that work?
Anyone used air shocks on a crawler with leaf springs before?

While innovative automotive creativity is always fascinating.....

I don't think your idea is a good one.

Gnarls.

[ryantowry_81]

if you are going to go that direction why not go full airbag?

Dave Chappelle (Dirthead_Dave on IG) from Dirt everyday has done multiple airbag suspensions on off road trucks with great success. very adjustable and seem to perform well.

He has used airbags on his "moms spaghetti" project as well as the Mazda build they call "Maz-Grande"

lots of good airbag info on them out there.

I have been contemplating air bagging the rear of my FJ80 for the same reason. load balancing and i find it snow wheels better with a little higher rear than front, which goes away when i have three passengers and gear in the back.


IIRC alot of the big snow wheeling guya up in Canada use airbags for adjustable ride height then add triple bypass shocks for good dampening control.

[arlindsay1992]

The latest (or maybe the next to latest) issue of 4WDTO has an interview with BigMike about RCLT. BigMike mentions some stuff about forced articulation in the works for the front suspension to do exactly what you're talking about. I think it said it can be forced to both extend and retract.

[ryantowry_81]

https://www.universalair.com/Coil-over-Bag-Brackets-By-Universal-Air-p/02-cobag.htm

I always thought this concept with a good limit strap could be cool. then if your air fails you dont loose all height and can not ride bump stops all the way home.

[Gnarly4X]

Air lift or air ride systems have been around for decades.

For leveling a truck for a vehicle for hauling loads there are multiple options.

The use of air bags or dynamically adjustable air shock is silly for rock crawling.

First, how would the driver know which shock to adjust?

How much adjustment is necessary?

How long will it take to get the desired adjustment?

It’s bad enough being behind a vehicle on rock crawling trail and at every obstacle the driver fondles his twin sticks trying figure out what hell gear he’s in and if that gear is going to be the right one for him to look the level of “coolness” he needs to look!!

Then there is the BIG reliability issue.  Air bags, air shocks, and ARB’s have well documented history of reliability issues.

Isn't there enough inherent reliability issues for a seriously setup vehicle for off-roading without introducing any more? 

Gnarls.

[ryantowry_81]

my interest in variable height suspension is not really for each individual obstacle but basically to setup the spring rate to handle the vehicle loading for a particular load/day. I can tell in my FJ80 when it is just me and the dog it behaves alot differently than when it is all three kids, dog, gear and me. rear of the rig sits at least 1.5" higher empty. And that is just day trip loading, not camping.

[a1gemmel [OP]]

I wouldn't use straight air bags for reliability reasons - I wouldn't want to puncture/rip a bag and need to swap it on a difficult spot in a trail.
Leafs carry the load, air shocks increase the spring rate. The failure case of a blown air shock in my mind is... well... graceful degradation to the setup I have now.
I am keeping leafs (as opposed to links) because I tow regularly with this truck, and like the progressive spring rate leafs offer.

Love Dave Chappelle, the guy is an understated fabrication genius.

Gnarls, I think your control concerns are addressing a straw man. You could say the same about tire pressure, manual lockers, adjustable dampers, etc.
If a group is behind me, I let them pass. If you're part of my group, then you're stuck with me anyways 

[Gnarly4X]

I wouldn't use straight air bags for reliability reasons - I wouldn't want to puncture/rip a bag and need to swap it on a difficult spot in a trail.
Leafs carry the load, air shocks increase the spring rate. The failure case of a blown air shock in my mind is... well... graceful degradation to the setup I have now.
I am keeping leafs (as opposed to links) because I tow regularly with this truck, and like the progressive spring rate leafs offer.

Love Dave Chappelle, the guy is an understated fabrication genius.

Gnarls, I think your control concerns are addressing a straw man. You could say the same about tire pressure, manual lockers, adjustable dampers, etc.
If a group is behind me, I let them pass. If you're part of my group, then you're stuck with me anyways 

OK…. After 20+ years of hardcore rock crawling, I did not see or know anyone who had any air shocks that were dynamically adjustable.

A dynamically instantly adjusting shock would be "gain of function".... could cause a bad case of COVID-19!!

I did see guys with ARB's that failed to operate.

Shocks are for reducing shock.  I’m a long way from a suspension expert, so help me understand how air shocks increase the spring rate? 
 
“Preloading does not change spring rate but preload does change the force to start moving the shock and high preload dramatically reduces shock performance over smaller bumps and makes for a more harsh ride and worse traction. Spring rate is the force required to move a certain distance whereas preload adds a fixed force across the whole stroke.”


I don’t know about a straw man, but on the trail I would rarely change tire pressure, I don’t have to touch my Detroit locker, I’ve never had “adjustable dampers”.  I have had Rancho 9000 adjustable shocks, but only adjusted them once or twice with that little black knob, and not on the trail during a run.

On the rock crawling trails I've been on, if you are taking more than a minute to negotiate on obstacle, I would NOT be part of your “group”! 

That’s just my opinion – it may be worthless.

Gnarls.

[ryantowry_81]

i would not be so worried about the bags ripping as lines. their are air bags under semi trucks supporting insane weight for long periods with no maintenance. the military Growler uses them as well. they have some internally bump stopped air bags as well, like this one:
https://www.truckspring.com/Products/Firestone-Reversible-Sleeve-Air-Spring__W01-358-5429.aspx

different strokes for different folks.

Have you searched around for any longer stroke air shocks? i havent looked at air shocks since i had my old 68 el camino

[ryantowry_81]

also I have seen some hydraulic over spring setups used for ride height adjustment. a little more complicated but another avenue to investigate.

[Snowtoy]

I have a few reasons for wanting this:
- load assist while towing

Air bags will work for this

- level the truck on uneven ground for sleeping in the bed

Air bags will work for this

- counter off-camber situations by maxing out the downhill shock
Is that last point even feasible?

Air bags would have little actual benefit here, as the amount of lift would likely not change the center of
gravity enough to reduce the potential to roll, likely just make the driver feel better.  The only way to have
anything that would do what you are envisioning, is a hydraulic suspension like this. https://www.youtube.com/watch?v=EmzVWEAD6wA

[camhays556]

I have seen a few guys run air shocks in the rear on quick disconnects to help with load in the bed on prerunners. Idk how you would make them air up with nitrogen on the trail but you could def run air shocks as a secondary shock to help with weight

[a1gemmel [OP]]

I looked more at airbags... I kind of think the Airlift Ride Control is what I want. They don't list the compressed/extended length specs on the site that I could find so I'll have to shoot them an email.
If / When I get around to doing this, it'll be in my build thread. The projects never end!