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Air Spring Identification Tips
Air Spring Identification Tips

Step 1

The easiest and fastest way to identify Firestone air springs is by the part number stamped on the top plate. If this is not present, look for the bellows number stamped on the rubber. The bellows number is normally molded directly underneath the Firestone logo.

Enter the last four digits of the part number into the search box on our site. If you do not know the Firestone part number or bellows number, you may enter and search using other parts numbers such as: Goodyear Part Number, Goodyear Bellows Number, Triangle Part Number, Triangle Bellows Number, Manufacturers number (Hendrickson, Neway, etc.) 

Step 2

Measure and compare dimensions. The cross sectional view of the Airide spring shows dimensional information in inches on uninflated diameter, maximum height, and collapsed height. Measure the bead plate diameter and molded (uninflated) diameter of the rubber bellows (please note that the molded diameter can grow slightly with years of service). Then measure from the bottom of the piston to the top of the bead plate while the part is uninflated and extended.

Step 3

Identify the top (bead plate) and bottom (piston) of the air spring. The same rubber bellows is used with many different combinations of bead plates and pistons, so be sure to check closely. Compare the bead plate and piston with the pictures from the “Cross Section View”, “Bead Plate Top View” and “Piston Bottom. You can view the images of the top plates and pistons by clicking on the “more images” button on the air spring product page. The piston can be further verified by reading the identification numbers inside the pistonand comparing these with those shown in the “Piston Bottom View”.


The bellows number (number 1T15M-6 in step 1 ) is the number of the rubber that is used on the air spring and is not the actual part number used to order an air spring. The same bellows number can be used on multiple air springs. It is very helpful in narrowing down the search, but is not the actual part number. The part number (assembly number) is a combination of the top plate, bellows and piston numbers and will typically look like W01-358-9082 is step 1.

Firestone Hardware Key

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Since 1926, Michigan Truck Spring has been installing and using the same high quality truck parts that you'll find on our website. In fact, we install everything we sell, and have been selling online as TruckSpring.com since 2001.

Whether you're looking to overhaul your truck suspension, or make a minor repair, our mission is simple - to make sure you have the quality parts you need, and to become your trusted source for truck parts.

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