Firestone Air Bags - Montana Owners Club

Jolu · 06-20-2009, 07:27 AM

Has anyone installed Firestone Air Bag Helper Springs on their newer Chevy 3500 DRW 4X4s?
What are the benefits of having them?

Countryfolks · 06-20-2009, 09:29 AM

Their primary purpose is to level a weight challenged, saggy rear[overloaded] vehicle. You shouldn't need them on your vehicle.

HughM · 06-20-2009, 10:36 AM

I had a 298RLS and with a 2500 Duramax we didn't need the air bags. But after buying a 13,000 lb rv we did put the air bags on so as to stop the 2-3 bounces we sometimes had. Now one bounce and that's it.

Art-n-Marge · 06-20-2009, 01:43 PM

Hey Jolu,

My rig combination (3/4 ton SRW, towing an Monty) warranted air bags - specifically we got the Firestone Air Bags. Prior to this my truck sagged under the weight (rode too low in the back) and this caused rear wheel shuddering when accelerating from a stop and too much jolting when driving on rough highways. HughM kinda touches on this when he upgraded his RV since he has a 3/4 ton.

Installing the air bags solved the shuddering since I could now raise the back end to a more level setting. It also smoothed out the ride when driving on rough roads.

In your case, your one ton DRW may not be exhibit these problems since your rear end is much stronger than mine, however, if you are willing to spend some dough to ease up the ride, then air bags are one solution since they can be inflated for a load and deflated when not carrying a load - i.e. provides flexibility. Hopefully other 1 ton dually owners will comment on the difference.

I also purchased an automatic compressor and controller so that any inflation/deflation is done from inside the truck's cab. The digital display controller enables me to alternately adjust either side as needed. Make sure you purchase the air bag system that supports your truck's rear end capacity! Refer to the RAWR for your truck for an idea what you need.

Other common improvements are MorRyde suspension for the RV and air bags at the pin hitch (Truck hitch or RV pin). Many other members have solutions recommendations for these.

exav8tr · 06-20-2009, 03:06 PM

Jolu, I have the same truck as you and do not feel that air bags are warranted, I am towing a "Fully" loaded 3400. When I had my 2500 I took the trailer and truck to a truck driving school and was advised to install air bags to: Keep the rig from bottoming out, sepecially on uneven surfaces. I did have them on the 2500 and recommend them for that truck, IF you are pulling a heavy trailer!!!! Hope this helps.

Jolu · 06-20-2009, 05:13 PM

Thanks to all of you for the replies. I think Art touched on something I have read in a couple of reviews about the bags smoothing out the ride when towing.
I guess I felt I really did not need them. The idea of perhaps maybe a little smoother ride when towing was an incentive to ask about them. I know several members who tow 5th wheels and have a hitch with air bags which gives a smoother ride for the trailer.

RickW · 06-21-2009, 03:16 AM

Jolu,

While I do think you have more then enough truck for your weights, I do think the airbags will give you a smoother more enjoyable ride.

I put airbags on my F250 when we were shopping for the Monty. Before the Monty we were pulling a 29' SOB. The 3400 is much heavier than our previous trailer. The first time we hooked up the Monty for the drive home from the dealer I noticed a big difference with the airbags. I wish I had done them sooner while still pulling the SOB. Personally I wish I had made the investment sooner. The airbags help my overweight issues but do not solve them. Only a bigger truck will solve the weight issues. The airbags will help soften your ride.

Chip · 06-21-2009, 04:33 AM

Jolu

I have them on mine as you can see by my signature. The truck did not need them at all. What made me put them on was (1) I had them from my previous 3/4 ton truck. (2) My Montana was not heavy enough to engauge the top overload spring but did settled the truck just enough that the spring would slap against the stop and create a loud noise when going over bumps. Drove me crazy.

So I took the top overloads off and added the air bags. Result was a much improved ride that I could adjust the way I wanted. Even with the overloads off, I don't think the truck needed them for this load however. I kept the springs so I can put them back on if I want to.

Drew

Countryfolks · 06-21-2009, 04:37 AM

Jolu, objectively an air bag is nothing more than an adjustable, progressive spring. Adding them to an existing leaf/coil spring setup increases the spring tension of the system, regardless of the amount of air in the bag. It's the same as adding a leaf to a leaf spring suspension. If you find you need added springing, by all means get them. If you're looking to smooth the ride while towing, look at one of the air ride hitches or pin boxes.
The newer light duty pickups have a spring system that uses light springs for unloaded use to promote a good ride, as the load increases the springs compress until the heavy duty springs are engaged for the trucks load rating. When the load rating is exceeded the truck squats and may ride on the axle bumpers, a rubber pad on the axle that prevents metal to metal contact.

richfaa · 06-21-2009, 07:33 AM

Humm. I do not understand the airbags giving a smoother ride?? Had them on my Previous Tv and did not note a smoothe ride towing or otherwise.. How do they provide a smoother ride?????

RonT · 06-21-2009, 10:01 AM

Like Richfaa I also wonder about the smoother ride. I added AirLift airbags since I also have a 10' truck camper and needed them on my F350 dually to level front to back and side to side. Prior to adding the airbags I had added Ranchero 9000 adjustable shocks to help with the sway caused by the truck camper. I love those shocks since I could adjust them down while going solo and that made a smooooth ride. After adding the air bags which I run a 5 psi (minimum allowed) while towing the 5th whl or going solo and the ride is now rough like the pre Ranchero days. With 5 psi the rear of the truck does sit a little low with the 39' SOB 5th wheel. Will see how the Montana sits when I get it in a couple of weeks. The SOB has a full 8 foot closet across the front which was packed full for the winter in Texas but the Monty does not have that big of front closet so pin weight should be less on it.

Tom S. · 06-24-2009, 06:05 AM

They smooth out the ride in two ways. First, by taking some of the load off the springs, they allow for more spring flex. On GM's, the springs are progressive, meaning the more compressed they become, the stiffer they get, so less compression equals smoother ride. Second, the bag acts similar to a shock absorber in cushioning some of the jarring bumps.

This is all predicated on using the correct air pressure for the amount of load of course. Too much air will causes a harsher ride as will too little.

Countryfolks · 06-24-2009, 07:41 AM

1. This would only be true if some of the energy of the load was transferred to some where else. In the case of added air bags [a second spring] the energy is still being transferred between the same places, ie. two springs in parallel dissipating 500# each are equal to a single spring dissipating 1000#.

2. Not true. If they did a basketball wouldn't bounce. They react just like a steel spring, compressing and rebounding almost instantly. A shock works by spreading impact energy over time.

Art-n-Marge · 06-24-2009, 08:19 AM

I am not sure about others' posts but in my case I towed my Monty without air bags for 2-3 trips. When the road is not smooth I could feel the trailer and truck bounce quite a bit. But the thing that concerned me most was the drop in the rear end and a shudder as I took off from a stop.

After installing the air bags and inflating them properly, the rear end problem was solved, the shudder was completely eliminated and I found a smoother ride on non-smooth roads when making the same trips we had made without the air bags. I will still feel a jolt on very rough bumps but it just doesn't seem as terrible as it was. This was further recognized by my wife who was impressed in the ride, so it wasn't just me.

However, since I have done nothing to improve the trailer (air hitch or moryde, etc.) I am pretty sure the trailer is getting smacked around pretty good. I try and keep my speed about 60-62 to help things out.

In Jolu's case the smoothness might be noticed as much. A precaution on the air bags: Check the weight rating on the system you select to ensure they help your truck. If you go through a dealer they should be able to help you make the proper selection if you bring it up.

Countryfolks · 06-24-2009, 08:54 AM

The shudder was probably caused by the drive shaft sections being too far out of line when the rear springs were compressed too far. My dealer suspected the same drive shaft mis-alignment when I had a shudder in my last truck. If you think about it, what you've done is add overload springs to a 3/4T in order to level a load that is nearing or past the design capacity of the stock springs. This addition is allowing the rest of the suspension to work properly. Steel overload springs would probably do the same thing [and cheaper], but without the adjustability of the air bags. I looked into this airbag/spring thing a bunch of years ago for a truck we had.

Tom S. · 06-30-2009, 01:41 PM

Quote:

quote:Originally posted by Countryfolks

1. This would only be true if some of the energy of the load was transferred to some where else. In the case of added air bags [a second spring] the energy is still being transferred between the same places, ie. two springs in parallel dissipating 500# each are equal to a single spring dissipating 1000#.

2. Not true. If they did a basketball wouldn't bounce. They react just like a steel spring, compressing and rebounding almost instantly. A shock works by spreading impact energy over time.

I have on board air, with a gauge. You can watch the air pressure increase then decrease with jolts in the road. Am I wrong then in believing the bag is absorbing and dissipating some energy? Ever try to bounce an under inflated basket ball? Doesn't it absorb the energy? The spring example is true, but with air bags, are you not in effect changing the rating by increasing/decreasing air pressure? If you don't think so, I would offer to take you for a ride with them set at 15 psi and at 100 psi.

Countryfolks · 06-30-2009, 03:50 PM

When the airbag is compressed the air pressure increases because the volume is decreased. Yes, the airbag is absorbing the energy, but it releases it as quickly as it absorbs it. If you transfer this energy from the input object to a separate output object the input object would not rebound and would feel 'softer/smoother'. Airbags absorb the energy created between the frame and the axle assembly when they are pushed towards each other, the problem is, when the airbags release the energy , it is released back to the same two objects. Hard to explain. Yes, increasing/decreasing air pressure is changing the [spring] rate, That is why I called it a progressive [or variable] rate spring. You would get the same effect [15 psi vs 100 psi] by doing the same thing using metal springs. Chip described the way to use airbags, as a replacement for overload springs. Yes, I've bounced an under inflated basketball, there's not as much 'spring'.

Delaine and Lindy · 06-30-2009, 04:55 PM

The benefit is to help take the sag out from the weight of the 5th wheel. But some do think it helps the ride. We have Air ride suspension (Large Air Bags) and Air ride seats with a Trailer Saver air ride 5th wheel hitch. However the Air ride suspension transfer the bumps upward. The 5th wheel rides on the Air ride 5th wheel hitch. The good ride comes from the Air ride seats. I owned several GM 3500 1 ton Trucks and actually had the Mor/Ryde reaf leaf rubber to make the ride better it did help some but we only run the Truck about 600 miles with the Mor/Ryde system. But as for sag on the GM Trucks I never had that problem. And the 5th wheel we have owned like the Cambridge 358 about a 3600 lb pin weight and the 5er we have now has a 3800 lb pin weight our Chevy 3500 1 ton didn't have any sag it set level when the 5er was hooked up. I really don't think the Air bags will make a difference in the ride of the 3500 1 ton. Good Luck with your choice. GBY....

Art-n-Marge · 06-30-2009, 05:35 PM

Hello Delaine and Lindy... a little off topic, but what does GBY stand for? Thanks.

sreigle · 07-01-2009, 07:03 AM

I had the Firestone airbags on a couple of my Fords. I also had the incab controls with air compressor. The advantages I found was ability to level the rear of the truck, eliminating sag, and also being able to smooth out the ride on the fly when we hit some of those roads that cause the herky-jerky motion. I could not eliminate the motion but was able to adjust the air pressure to make the ride acceptable in those situations.

I also could drop the pressure to zero when solo. The manual says to keep 5 psi in the bags when the bed is empty so the bags are not damaged should you bottom the suspension. On my trucks, there is no way I'm going to bottom that heavy rear suspension when empty so I dropped them to zero. I used the bags on those two trucks over several years and never had a problem with them.

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