2020 1500 AT4 Firestone airbag install, spacers required?

sh!tmagnet · February 1, 2021

Hi everyone, new to the forum here and haven't seem to be able to find an answer after searching.

Purchased a 2020 1500 AT4 last summer(love the truck), and recently added the Firestone Ride-Rite kit to the rear(kit #2609). I also ordered the 2" spacer kit as recommended (kit #2366).

I'm having a bit of a problem with the install and was wondering if anyone else has added rear air bags to their AT4, and did you end up using the spacer or were you fine without it?

Problem is the air bags are slightly misaligned, and appear "under-inflated" with the spacer in there even when I have 10-20psi in them(there is about 500lbs in/on the box via a canopy and a Decked box system installed in the bed; I'd rather not have to try and remove these unless I absolutely need to, to diagnose the problem).

I know in the instructions it says to have 5.5-6.5" of space between the upper and lower mounts. So my next plan is to jack up the back of the truck enough via the hitch receiver to recreate the correct factory fender gap front to back(should be roughly 1.5" from the factory with no load if I'm no mistaken?), and then measure the distance between the new mounts.

Thoughts and/or someone who has added rear airbags to their AT4? I'd assume the Trail Boss would be very similar?

Cheers

calgator73 · February 1, 2021

19 minutes ago, sh!tmagnet said:

Hi everyone, new to the forum here and haven't seem to be able to find an answer after searching.

Purchased a 2020 1500 AT4 last summer(love the truck), and recently added the Firestone Ride-Rite kit to the rear(kit #2609). I also ordered the 2" spacer kit as recommended (kit #2366).

I'm having a bit of a problem with the install and was wondering if anyone else has added rear air bags to their AT4, and did you end up using the spacer or were you fine without it?

Problem is the air bags are slightly misaligned, and appear "under-inflated" with the spacer in there even when I have 10-20psi in them(there is about 500lbs in/on the box via a canopy and a Decked box system installed in the bed; I'd rather not have to try and remove these unless I absolutely need to, to diagnose the problem).

I know in the instructions it says to have 5.5-6.5" of space between the upper and lower mounts. So my next plan is to jack up the back of the truck enough via the hitch receiver to recreate the correct factory fender gap front to back(should be roughly 1.5" from the factory with no load if I'm no mistaken?), and then measure the distance between the new mounts.

Thoughts and/or someone who has added rear airbags to their AT4? I'd assume the Trail Boss would be very similar?

Cheers

I've been looking at modifying my AT4 with a set of the firestone bags and these:

https://www.daystarweb.com/product/air-bag-cradle-polyurethane-black

These would install on your lower spacer and allow full rear axle travel.

Got pictures?

sh!tmagnet · February 2, 2021

5 hours ago, calgator73 said:

I've been looking at modifying my AT4 with a set of the firestone bags and these:

https://www.daystarweb.com/product/air-bag-cradle-polyurethane-black

These would install on your lower spacer and allow full rear axle travel.

Got pictures?

Here's pictures, with and without spacer, passenger side and then drivers side. Each sitting at about 12-15 psi. Space between mounts was around 5.5" without the spacer in there, so I'm not really sure why every source I find for this kit recommends adding the 2" spacer???

Also not overly happy the bags don't sit totally vertical but there isn't much adjustment in these mounts(bottom mount has a slot about 2" long front to back.) The lower mounting bolt on the airbag is pushed as far forward in the slot as it will go.

calgator73 · February 2, 2021

You're right...that is hideous. are the tires on the ground or axle being supported with jacks in these photos? Comparing their kit with air lift it's interesting.

https://www.airliftcompany.com/content/manuals/MN-1085.pdf

The Ride-rite directions do not mention removing the spacer inboard of the springpack. They don't even show it exists.

Gangly · February 2, 2021

WHOA, that is definitely not right. Some of the spacers are angled, is it possible the spacers were put in backwards resulting in such an obvious misalignment? It looks like the rear axle is rotated resulting in non-parallel mounting surfaces.

**After looking further, it looks like the upper mounting plates are installed too far back. Is there anyway to shift the mounting location of the upper mounts?

Edited February 2, 2021 by Gangly

sh!tmagnet · February 2, 2021

6 hours ago, calgator73 said:

You're right...that is hideous. are the tires on the ground or axle being supported with jacks in these photos? Comparing their kit with air lift it's interesting.

https://www.airliftcompany.com/content/manuals/MN-1085.pdf

The Ride-rite directions do not mention removing the spacer inboard of the springpack. They don't even show it exists.

Tires on the ground.

I went with the Ride-Rite kit since it was a flawless install on my wife's 2015 F150. But with this setup, I'm not super impressed.

Maybe it has something to do with the leaf spring lift blocks for the AT4 and "rotating the pinion angle for the additional lift" that makes the axle bump-stop block(pictured in Airlift's setup but not in Ride-Rite's) mounting surface angled causing the misalignment?

sh!tmagnet · February 2, 2021

1 hour ago, Gangly said:

WHOA, that is definitely not right. Some of the spacers are angled, is it possible the spacers were put in backwards resulting in such an obvious misalignment? It looks like the rear axle is rotated resulting in non-parallel mounting surfaces.

**After looking further, it looks like the upper mounting plates are installed too far back. Is there anyway to shift the mounting location of the upper mounts?

The only adjustment on the whole mounting setup is the lower mount that has a slot for the lower airbag bolt. Upper mount has no adjustment and all mounts are the same side to side, ie: there is no way to install them backwards.

As for the spacers, the center hole was used, there is two outer threaded holes on the spacer was well, but I didn't try that, as I realized the spacer doesn't appear to be necessary.

Edited February 2, 2021 by sh!tmagnet

sh!tmagnet · February 2, 2021

For reference.

https://www.firestoneip.com/rr-kit-install-manuals/W217602609.pdf

calgator73 · February 2, 2021

17 minutes ago, sh!tmagnet said:

The only adjustment on the whole mounting setup is the lower mount that has a slot for the lower airbag bolt. Upper mount has no adjustment and all mounts are the same side to side, ie: there is no way to install them backwards.

As for the spacers, the center hole was used, there is two outer threaded holes on the spacer was well, but I didn't try that, as I realized the spacer doesn't appear to be necessary.

It looks like firestone is compensating for a short bag. The bags themselves are the same no matter what. (airlift two different length bags and no spacer) You might have to use them to keep you from overextending them during full droop. Their customer service have any words of enlightenment?

sh!tmagnet · February 2, 2021

9 minutes ago, calgator73 said:

It looks like firestone is compensating for a short bag. The bags themselves are the same no matter what. (airlift two different length bags and no spacer) You might have to use them to keep you from overextending them during full droop. Their customer service have any words of enlightenment?

They said as long as it's 5.5-6.5" between mounts (unloaded), then you're fine; which it is, based on a fender gap of 1.5"(approximately) difference front fender to back fender. But that also strikes me as a bit odd considering this has a 2" factory lift, so the distance between mounts on standard Sierra 1500 would be less no?

Any chance someone can double check their stock AT4 fender height front and back? I was sure it was around 1.5" or so.

calgator73 · February 2, 2021

50 minutes ago, sh!tmagnet said:

They said as long as it's 5.5-6.5" between mounts (unloaded), then you're fine; which it is, based on a fender gap of 1.5"(approximately) difference front fender to back fender. But that also strikes me as a bit odd considering this has a 2" factory lift, so the distance between mounts on standard Sierra 1500 would be less no?

Any chance someone can double check their stock AT4 fender height front and back? I was sure it was around 1.5" or so.

Just checked mine. Measured ground through center of wheel to fender lip. F 38 1/2 R 40 3/4 My comment regarding the short bags has to do with articulation. Max length on those is 8.4". This axle can really droop quite far without the bag. I think they are adding the spacer to preserve that articulation.

Part of the rear lift is a taller tire and a different block. I'm not sure if the spacer for the bumpstop increased or decreased in size from the normal trucks. you would have to measure both from the pad (no spacer) to the bump stop mount to confirm that relationship.

atxat4 · March 14, 2021

That definitely looks rough. I put the airlift airbags on my 2020 AT4. They have a kit specific to the At4. The spacers are built in and part of the package. The base for them looks a lot sturdier on airlift versus the ones in your pic. I’ve never installed airbags before but they went on pretty easily. Only downside is that I have the readylift level kit and they seemed to push the back end up off level without being inflated more than the minimum. Good news is that the readylift almost pushed the front end too high. I actually on had to add a 1/4” wedge ont the blocks to keep it from looking like the bed was sagging. The readylift level with the airbags essentially gave me the option to take it feom a level kit to making it look like the readylift sst 2” kit minus the 1/4” difference in the front. I just use the airlift app the goes with their wireless pump and bam... I have a lift in the back too. https://www.airliftcompany.com/shop/88388/

Edited March 14, 2021 by atxat4
Change to notify me if their is a response

atxat4 · March 14, 2021

The airlift kit really turned out nice

outlaw_country_fan · May 13, 2021

@atxat4 - How did your AT4 sit after the airlift kit was installed? Did it raise the rear at all?

Edited May 13, 2021 by outlaw_country_fan

atxat4 · May 15, 2021

The backend came up about an 1” bc I bought the one with internal jounce bumper. It should come back down once they’re broken in. Made it look like a lifted truck since it was already leveled. I like the jounce bc it protects the bags. 4wheel parts said they don’t install ones with jounce bc it raises truck back unless consumer wants them.