Rear Shocks 3500 with Air Suspension

[DonRam240]

I just sent the KYB tech email address this query, will report reply if it doesn't show up here first:
"KYB tech: Following up on "Rear shocks 3500 with Air Suspension" thread on Turbo Diesel Register website. I see from another person's post that you now have a part number for a rear shock to fit my 2018 Ram 3500 with the factory rear air self leveling suspension.
Can you say how the valving for low speed bumps, especially for jounce, compares to the factory shocks? It's the relatively mild, low speed bumps with low suspension velocity that cause bottoming (and back pain) with factory shocks when I have the heavy pickup camper in the bed."

THE RESPONSE FROM KYB is below. I had been planning to invest in custom shocks from Thuren Fabrication, probably a $1200-or-so pricetag. Now, given the KYB Gas-a-Just's increase in damping rates, which looks likely to be a solution, I think that will be the first experiment to try. Results to follow, after installed and I have the next chance to drive the truck with camper onboard.
Don
"On average our Excel-G has a 10-15% increase and the Gas-a-Just has 25-30% increase over the OE damping rates.
Regards,
Technical Support
KYB Americas Corporation
techsupport@kyb.com"

 

[EZeis]

THE RESPONSE FROM KYB is below. I had been planning to invest in custom shocks from Thuren Fabrication, probably a $1200-or-so pricetag. Now, given the KYB Gas-a-Just's increase in damping rates, which looks likely to be a solution, I think that will be the first experiment to try. Results to follow, after installed and I have the next chance to drive the truck with camper onboard.
Don
"On average our Excel-G has a 10-15% increase and the Gas-a-Just has 25-30% increase over the OE damping rates.
Regards,
Technical Support
KYB Americas Corporation
techsupport@kyb.com"

They don't make a Gas-a-just for this application. It's a Excel-G line only 3450014. Also their reply is a generic average and not application specific to the 3450014. It could provide little to no improvement over the OE shocks. Their cost at 50 bucks each, a red flag that I'd be disappointed.

Earl

 

[HarryOlson]

I don’t have the part numbers but FOX Shocks does have adjustable reservoir shocks for 2019 and later 3500 SRW trucks. Below are pictures of mine installed. They are very nice but expensive.

 

[HarryOlson]

 

[EZeis]

I don’t have the part numbers but FOX Shocks does have adjustable reservoir shocks for 2019 and later 3500 SRW trucks. Below are pictures of mine installed. They are very nice but expensive.

Specifically for air suspension models or did you install for non air suspension?


Earl

 

[HarryOlson]

Mine is for 2019 air suspension.

 

[EZeis]

Mine is for 2019 air suspension.

Cool, I will look into those. If the shock length isn't correct, the air bag turns into the suspension limiter and they will eventually fail. So it's important to have the same shock stroke as OE to protect the bags from over extension.


Earl

 

[EZeis]

View attachment 125165 View attachment 125166

Just checked their web site application and their download catalog. No mention of air suspension at all on 3500. I would believe they aren't compatible with air suspension as they would be a separate part number like mopar and KYB for air suspension.


Earl

 

[Cummins12V98]

I probably have said it but I see no reason to change out the OE rears.

I have Bilstein on the fronts but they could stand improvement.

 

[EZeis]

I probably have said it but I see no reason to change out the OE rears.

I have Bilstein on the fronts but they could stand improvement.

Yes, you have, numerous times! Mine aren't worth a flying ****. Everyone has different tastes and opinions. If I didn't have to drive over bridges and dips, I'd probably be happy with the factory rear shocks, for now. That said, I never cared for any factory shocks/struts. They spend little time and money on their development. Also they never last long. These rears will be gone as soon as I find a fully completely compatible better high quality shock. Unfortunately bilstein aren't making them. KYB are the only ones that make one specifically for air suspension. I have no experience with them and their price point puts them in the low quality group.


Earl

 

[HarryOlson]

Well Earl I believe you believe that FOX does not have shocks that are compatible with our air ride trucks. If you choose to ignore the shocks installed on my truck by FOX, that’s your choice. If, in fact, you want more and accurate information, why don’t you call FOX direct here in Southern California? They should be able to give you all the information you need. Regards, Harry

 

[EZeis]

Well Earl I believe you believe that FOX does not have shocks that are compatible with our air ride trucks. If you choose to ignore the shocks installed on my truck by FOX, that’s your choice. If, in fact, you want more and accurate information, why don’t you call FOX direct here in Southern California? They should be able to give you all the information you need. Regards, Harry

That is correct as they don't list air suspension on the 2500 or 3500 on their website or catalog. Also they specifically say no on 1500 air suspension trucks applications. Not ignoring you or your kick ass shocks. I don't believe they are fully compatible with stock unlifted air suspension trucks. I believe you have shocks for non air suspension 3500's. Do you have a manual or something that says they are completely compatible with unmodified air suspension 3500's? I will see if they have an email contact. If their site and catalog doesn't list them, I doubt they have anything. Hard to sell something you don't make public/advertise. For you I will email them, if they list an email. I'd be extremely shocked if they do, to which I will inquire as to why they don't publish them.

Earl

 

[AEdelheit]

You guys are wayyyy overthinking this, the important specs on a shock is the extended length, collapsed length and valving.

I have seen Fox and King shocks on air ride trucks with massive improvement over stock due to the increased rebound dampening. The only length we are really concerned about is the extended length as if that is correct the collapsed length will be fine in this application, the air system has no clue what shocks are on the truck and as long as they are not too long causing the bags to overextend then it doesn't care what shocks are used.

Just because a book doesn't say they will fit does not mean they will not, just that the manufacturer has not spent the time for such a small application. If someone feels the stock shocks work well then good for that person but they also have no idea how much of a difference a good shock can make as the stock ones are terrible.

 

[EZeis]

You guys are wayyyy overthinking this, the important specs on a shock is the extended length, collapsed length and valving.

I have seen Fox and King shocks on air ride trucks with massive improvement over stock due to the increased rebound dampening. The only length we are really concerned about is the extended length as if that is correct the collapsed length will be fine in this application, the air system has no clue what shocks are on the truck and as long as they are not too long causing the bags to overextend then it doesn't care what shocks are used.

Just because a book doesn't say they will fit does not mean they will not, just that the manufacturer has not spent the time for such a small application. If someone feels the stock shocks work well then good for that person but they also have no idea how much of a difference a good shock can make as the stock ones are terrible.

Yep, that's why I've been anal about the proper application. You don't want the air bags to become the suspension limiter! The shocks need to remain the limiter. But no one that changed their rear shocks has come forward with the OE shocks lengths. So we have no idea if the OE air suspension shocks have the same lengths as OE non air suspension trucks. Is it just valving? Is it just lengths? Or both? That's not overthinking, that's protecting the air bags from the wrong shock lengths. There is a reason why Mopar and KYB have separate parts numbers. It's it different lengths? Different valving? Both? That's the extremely important thing, lengths. Sorry I'm not! Lol others can throw whatever shocks they want on with no regards to their air bags, but not this guy. Ram won't warranty an overextended air bag from improper shocks.

I did email Fox yesterday. I will post what they reply. I have no experience with them either. Looking at their price point, they are either extremely high end or just overpriced for the name. Their basic shock starts out at 170.00 compared to KYB's 50.00.


Earl

 

[EZeis]

Just got the reply from Fox. I copied it word for word. They don't offer shocks for factory air suspension trucks, which is why they aren't listed on their site or catalog. Now if the shock length for air and non air are the same, you could use any shock for non air trucks. But will the valving be good for air bags? The mystery of the OE air suspension shock lengths. Lol if the lengths were correct, an adjustable shock would work too and could be fine tuned. They confirm they don't even know about fitment, the most important thing. So back to waiting for a direct application high end shock.

Hello Earl,

Unfortunately we have not done any testing on the air-ride models and cannot confirm fitment or performance.

Many customers have used our shocks on their vehicles with aftermarket load assist systems and provided good feedback, however we do not explicitly make a product for that application.

Thank you,

Ryan G
Sales Department
Offroad Division
Truck | SUV | Offroad Race | Defense
orsales@ridefox.com
619-768-1800 // 750 Vernon Way Ste. 101 El Cajon, CA 92020
ridefox.com // @fox // #ridefox
For Order placement/ Order status/ Cancellations, please contact ororders@ridefox.com
http://ridefox.com/truck_info

 

[AEdelheit]

Yep, that's why I've been anal about the proper application. You don't want the air bags to become the suspension limiter! The shocks need to remain the limiter. But no one that changed their rear shocks has come forward with the OE shocks lengths. So we have no idea if the OE air suspension shocks have the same lengths as OE non air suspension trucks. Is it just valving? Is it just lengths? Or both? That's not overthinking, that's protecting the air bags from the wrong shock lengths. There is a reason why Mopar and KYB have separate parts numbers. It's it different lengths? Different valving? Both? That's the extremely important thing, lengths. Sorry I'm not! Lol others can throw whatever shocks they want on with no regards to their air bags, but not this guy. Ram won't warranty an overextended air bag from improper shocks.

I did email Fox yesterday. I will post what they reply. I have no experience with them either. Looking at their price point, they are either extremely high end or just overpriced for the name. Their basic shock starts out at 170.00 compared to KYB's 50.00.


Earl

Yes I did also mention length but the bags dont care about valving, the shocks have no connection to the air ride system other then keeping the bags from overextending. The cheap small OEM shocks can not have enough rebound valving to really control the bags, they would overheat so a large benefit to larger shocks is better valving so I dont care what valving is in the oem shocks.

If someone was really overly concerned about overextending the bags then put limit straps on, at that point shock length in not an issue.

 

[EZeis]

Yes I did also mention length but the bags dont care about valving, the shocks have no connection to the air ride system other then keeping the bags from overextending. The cheap small OEM shocks can not have enough rebound valving to really control the bags, they would overheat so a large benefit to larger shocks is better valving so I dont care what valving is in the oem shocks.

If someone was really overly concerned about overextending the bags then put limit straps on, at that point shock length in not an issue.

Yep, one could buy a high end adjustable shock at about any length and use limit straps to keep the OE shock extended length. My truck is a street truck, so I don't need or want limit straps. I will continue to wait for a direct fit shock for the application. KYB did, I'm sure more will follow, eventually.

I will email KYB for the specs between the air and non air part numbers to see if they are the same lengths.

Earl

 

[EZeis]

KYB actually had their shock data on their site.

3450014 for air suspension 21.61 extended length, 12.75 compressed length and 8.86 stroke.
345062 for non air suspension 27.55 extended length, 16.5 compressed length and 11.05 stroke.

Wow 6" difference on the extended length between the two KYB shocks. So a non air suspension KYB shock has 6 more inches on the extended length. That's huge! Makes me wonder if the two OE shock applications match KYB numbers.


Earl

 

[NonFord]

I installed the Eibachs on my truck. I measured the rears as well as the fronts compressed and extended. They were identical to the stock shocks, both rear and fronts. Also, when folks put on aftermarket bags, why isn't this much chatter that the shocks will not work now????? I also see no disclaimer from the shock companies to NOT USE AIR BAGS with our shocks. I agree with AEdelheit, way too much overthinking. I have 18K on this setup and couldn't be happier.

 

[EZeis]

I installed the Eibachs on my truck. I measured the rears as well as the fronts compressed and extended. They were identical to the stock shocks, both rear and fronts. Also, when folks put on aftermarket bags, why isn't this much chatter that the shocks will not work now????? I also see no disclaimer from the shock companies to NOT USE AIR BAGS with our shocks. I agree with AEdelheit, way too much overthinking. I have 18K on this setup and couldn't be happier.

What were those lengths? Part numbers? Never heard of Eibacks. Where they for air suspension or non? More info please.

You're one to point fingers for overthinking, you measured the shocks, original and replacement. You overthinker, you! Lol

Aftermarket bags kits are typically for stock ride height. So when the shocks are replaced they are typically the same spec as the truck is most likely stock. I added air bags to my 07 with factory shocks and later replaced with bilstein 4600 series. They were the same lengths. Also aftermarket air bag instructions clearly state the bags can't be the suspension limiter or they will become damaged. That is the shocks or limit straps job.


Earl