10-08-2024, 01:57 PM
This seams to be the topic of much discussion and many doubts on availability. I'm not going to pay over 250 for an airbag. The key things to look for when changing them to a newer style is the bellows, bolt spacing, and compressed height. The base is irrelevant, unless your base/pedestal is broken. the main section of the bellows can be removed from almost every bag and replaced with the base you have on your coach. With that being said here are the closest and least fabrication needed bags to use as replacements for the Firestone 9447 bags.
First we'll start with the dimensions of the "stock" 9447 bags that are impossible to find.
You'll notice the key features are the impossible 1 inch inlet and the center plug is a 3404. collapsed height is 4.80 inches total ride height is 13.80 inches not counting any over lift that might be used.
Next we compare this to 9477
This bag will work for you with only needing a 1inch to 3/4 reducer on the air inlet. lets say you cant find this bag (or in my case they wont ship to Alaska) we can look at other bags that will work.
This bag will also work. Same thing needs a 1 inch to 3/4 reduction bushing. This bag is also readily available here. https://www.truckandtrailer.parts/contit...-001804591 You will need to remove the center bolt and reuse your existing pedestal. It is 1/4 inch taller when collapsed so you'll need to droop the suspension to get it in there
This bag will also work the downside is you will have to jack up the coach and "droop" the suspension because the collapsed height is 3/4 inches taller than stock. You will also need the 1 inch to 3/4 reduction bushing and reuse your existing pedestal. This bag is also readily available at the same place.
If for some reason you cant reuse the existing pedestal grab a Dremel tool with a tiny cutoff wheel and remove the 2 studs from the bottom of the new base. Remove the center bolt holding the pedestal onto the bellows. Then before installing into your coach get some new standard center studs and reinstall using the center stud to hold everything together.
Ill be replacing all 8 with 9376 as i can get these locally from Trailercraft or Peterbilt for 165 each. However this will be done in the spring as there's no point doing it now just to let it sit outside and freeze. I've also added the firestone catalog and the goodyear to the bottom as PDF files As well as a link to the best cross reference site i have found.
https://www.truckandtrailer.parts/air-sp...ences.html
First we'll start with the dimensions of the "stock" 9447 bags that are impossible to find.
You'll notice the key features are the impossible 1 inch inlet and the center plug is a 3404. collapsed height is 4.80 inches total ride height is 13.80 inches not counting any over lift that might be used.
Next we compare this to 9477
This bag will work for you with only needing a 1inch to 3/4 reducer on the air inlet. lets say you cant find this bag (or in my case they wont ship to Alaska) we can look at other bags that will work.
This bag will also work. Same thing needs a 1 inch to 3/4 reduction bushing. This bag is also readily available here. https://www.truckandtrailer.parts/contit...-001804591 You will need to remove the center bolt and reuse your existing pedestal. It is 1/4 inch taller when collapsed so you'll need to droop the suspension to get it in there
This bag will also work the downside is you will have to jack up the coach and "droop" the suspension because the collapsed height is 3/4 inches taller than stock. You will also need the 1 inch to 3/4 reduction bushing and reuse your existing pedestal. This bag is also readily available at the same place.
If for some reason you cant reuse the existing pedestal grab a Dremel tool with a tiny cutoff wheel and remove the 2 studs from the bottom of the new base. Remove the center bolt holding the pedestal onto the bellows. Then before installing into your coach get some new standard center studs and reinstall using the center stud to hold everything together.
Ill be replacing all 8 with 9376 as i can get these locally from Trailercraft or Peterbilt for 165 each. However this will be done in the spring as there's no point doing it now just to let it sit outside and freeze. I've also added the firestone catalog and the goodyear to the bottom as PDF files As well as a link to the best cross reference site i have found.
https://www.truckandtrailer.parts/air-sp...ences.html
Carl Little
1996 Coach 435 Detroit 60