Rear Shocks 3500 with Air Suspension

[AEdelheit]

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

Something seems odd here as a leaf spring truck does not have 4" less up travel then an air ride truck, the shock mounting points are the same regardless or air ride so I suspect the part numbers or the measurements are wrong.

 

[AH64ID]

Something seems odd here as a leaf spring truck does not have 4" less up travel then an air ride truck, the shock mounting points are the same regardless or air ride so I suspect the part numbers or the measurements are wrong.

The non-air trucks do sit 2" higher than air trucks statically. Between that and different bumpstops I wonder if it's possible?

 

[EZeis]

Something seems odd here as a leaf spring truck does not have 4" less up travel then an air ride truck, the shock mounting points are the same regardless or air ride so I suspect the part numbers or the measurements are wrong.

Part numbers and specs from their site. I triple checked the part numbers and specs. If their is an error, it's in their specs and/or application listings.

Earl

 

[EZeis]

The non-air trucks do sit 2" higher than air trucks statically. Between that and different bumpstops I wonder if it's possible?

The non air spring pack is a lot thicker than the couple leafs on an air truck. That would be a difference between the two as well. That could be the 2" you mentioned?


Earl

 

[AH64ID]

The non air spring pack is a lot thicker than the couple leafs on an air truck. That would be a difference between the two as well. That could be the 2" you mentioned?


Earl

I think the difference is designed ride height, not spring pack difference. The non-air trucks need to sit higher to allow for sag underload, while the air trucks do not.

 

[EZeis]

I think the difference is designed ride height, not spring pack difference. The non-air trucks need to sit higher to allow for sag underload, while the air trucks do not.

If that's the case, the difference in spring pack thickness could make up most or all of the 6" difference. A 3500 spring pack is pretty damn thick. The air trucks only have a couple. But they could use spacer blocks or different size ones. Who knows. The guys that replaced their OE shocks didn't measure them or don't what to share it the info. I can disconnect 9ne of my shocks and measure the lengths, but without the non air truck length, it's useless as all applications expect KYB are for non air.

Earl

 

[AH64ID]

If that's the case, the difference in spring pack thickness could make up most or all of the 6" difference. A 3500 spring pack is pretty damn thick. The air trucks only have a couple. But they could use spacer blocks or different size ones. Who knows. The guys that replaced their OE shocks didn't measure them or don't what to share it the info. I can disconnect 9ne of my shocks and measure the lengths, but without the non air truck length, it's useless as all applications expect KYB are for non air.

Earl

The non-air spring pack isn't that much thicker than the air spring pack. I haven't put a tape to it, but it doesn't look much different to me.

Maybe someone can measure theirs. The air spring pack is 3" thick at the u-bolts.

 

[EZeis]

The non-air spring pack isn't that much thicker than the air spring pack. I haven't put a tape to it, but it doesn't look much different to me.

Maybe someone can measure theirs. The air spring pack is 3" thick at the u-bolts.

I can only guess as I have an air truck and haven't looked at an non air truck. I don't know anyone with a 4th gen. I'd have to look at the dealer. But the late trucks might be different.


Earl

 

[AH64ID]

Just measured a 19+. Spring pack is a 1/2” thinner on non air, but the blocks are different so the top spring is at the same height above the axle, or nearly the same height. Air has 1 ~3/8” shim and non-air has 3 ~3/8” shims.

 

[NonFord]

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

Earl

I didn't physically put a tape on them, just lined them up on the floor. Stretched and compressed the same lengths. I did this only as a quick reference because of all the talk air vs non air. Also, when I started this journey the shock debate goes even further than air vs non air. There is also a OEM shock for excluding 20" wheels on air suspension trucks, that's a head scratcher too.
Eibach Part # Front: E60-27-006-03-10 Rear:E60-27-009-02-01

https://eibach.com/us/c-56-car-truck-suv.html

 

[EZeis]

I didn't physically put a tape on them, just lined them up on the floor. Stretched and compressed the same lengths. I did this only as a quick reference because of all the talk air vs non air. Also, when I started this journey the shock debate goes even further than air vs non air. There is also a OEM shock for excluding 20" wheels on air suspension trucks, that's a head scratcher too.
Eibach Part # Front: E60-27-006-03-10 Rear:E60-27-009-02-01

https://eibach.com/us/c-56-car-truck-suv.html

Well I be ******! Another variable!!?? Lol My air truck has 18" wheels.

Your aftermarket shocks take care of the pogo effect like when hitting dips and some bridges? Or the delayed bounce when it isn't pogoing? When loaded that is. That's my complaint. I tow a 12.5k 5th wheel with 2700 lbs of pin weight (scaled). Loaded normal and alternate ride heights don't seem to differ it either.

Earl

 

[NonFord]

Yes, the pogo effect has been nicely reduced (your not like a bobblehead doll now). I carry a Lance 855s slide in camper, and I can tell you that I actually smoothed out the ride with this beast. Additionally, I did have the factory 20's on and took those off , put on factory 18's (vibration when empty gone now). Once I made these changes, truck runs very nice, especially loaded down.

 

[AH64ID]

I can’t say I’ve experienced the pogo effect. Are both your trucks SWB?

 

[NonFord]

I can’t say I’ve experienced the pogo effect. Are both your trucks SWB?

Mine is...

 

[EZeis]

I can’t say I’ve experienced the pogo effect. Are both your trucks SWB?

No I'm long bed. my truck stats. 2018 tradesman crew cab long bed 4wd SRW aisin. 2700 lbs of 5th wheel pin weight. All stock. 18" wheels.

Earl

 

[sarj]

I had them all - and they are all junk compared to an High End Shock that is valved for the exact application.
A truck with such shocks is like a flying carpet, perfectly smooth but the same time firm on the road.
Uncomparable.

Ron you said you have money to waste - so waste it for a set of custom valved King or Fox and you'll feel the difference, and in the end the money will not be wasted. You would be amazed how much better your truck drives.

I saw this is an old thread and I didn't follow it all the way through, but if the issue is still up, what Ozy said is exactly true. I met The King folks at an off-road show, and ended up upgrading from bilsteins to Kings, and the money is not wasted. I'd do it again with no reservations. With my short lift/leveling I added when the truck was new, I was looking for something with the right travel and valving. Not sure about the air suspension issue, but I've been catching up on new trucks in this forum since I'm looking for something adequate to pull a pending 5th. It's nice their factory is just up the ways from me so I can stop in, but I wouldn't hesitate to call King to see what they have.

 

[DonRam240]

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

I couldn't find a clearly identified Gas-a-Just application, either. The reply to my email from KYB tech was this, when I told them I couldn't find a Gas-a-Just application with a note to the effect of "for vehicle WITH factory air suspension," though there is one now (5550006) that doesn't have the note "NOT for .... air suspension."
"The part numbers are Excel-G 3450014 or Gas-a-Just 5550006. These are the rear shocks to be used with factory rear air suspension."
I've ordered a pair of 5550006, estimated ship date from Summit Racing is Dec. 8th, will report results as I have a chance to use truck with camper on it in coming months. Between the "15-25%" firmer valving and higher gas pressure to better maintain that firmer damping with heavier cycling under the camper load, I'm cautiously optimistic.
Don

 

[lpennock]

Would be nice if you did a collapsed and extended length compare between them and the factory shocks, also.

 

[EZeis]

I couldn't find a clearly identified Gas-a-Just application, either. The reply to my email from KYB tech was this, when I told them I couldn't find a Gas-a-Just application with a note to the effect of "for vehicle WITH factory air suspension," though there is one now (5550006) that doesn't have the note "NOT for .... air suspension."
"The part numbers are Excel-G 3450014 or Gas-a-Just 5550006. These are the rear shocks to be used with factory rear air suspension."
I've ordered a pair of 5550006, estimated ship date from Summit Racing is Dec. 8th, will report results as I have a chance to use truck with camper on it in coming months. Between the "15-25%" firmer valving and higher gas pressure to better maintain that firmer damping with heavier cycling under the camper load, I'm cautiously optimistic.
Don

Please keep us posted. Please measure the eye center to eye center length of the OE and replacement shocks as well for extended length and compressed length.

Earl

 

[DonRam240]

Please keep us posted. Please measure the eye center to eye center length of the OE and replacement shocks as well for extended length and compressed length.

Earl

Thanks, yes, have measured OEM's already and will measure KYB's before installation the same way.