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HOW TO INSTALL A FLOWMASTER PRO SERIES AXLE-BACK FOR YOUR 2005-2010 MUSTANG GT AND GT500

Installation Time

1 hours

Tools Required
  • 15mm Socket
  • 13mm Socket
  • Socket Wrench
  • 13mm ratcheting box-end wrench or adjustable wrench
American Muscle
Shop Parts in this Guide

Installation

Step 1

Pick a side to start with. Loosen the nut on the clamp that connects the mufflers to the over-axle pipe with a 15mm socket (no need to remove it). 


Step 2

Each muffler has two hangers supported by two bolts each. Use a 13mm socket to remove them on the rear most hanger first. 


Step 3

Now do the last hanger on that side. As the bolts become loose, try to support the muffler just to be safe. 


Step 4

Now slide the muffler off the over-axle pipe. 

Repeat these steps 1-4 for the other side. It should look like this. 



Step 5

With a 15mm socket, remove the nut from the clamps supplied in the kit and slip a little grease on the threads for anti-seize purposes. Slide these onto the Flowmaster mufflers. 

Step 6

Slip on the muffler hangers to the Flowmasters (the left side for the left muffler and right side for the right muffler). 



Step 7

Pick a side. Take the muffler for that side, and slide it on the over-axle pipe until the knob on the pipe is inside the cutout on the muffler pipe. While supporting it, tighten the clamp a bit and keep the support for safety’s sake. 


Step 8

With the 13mm, install the rear hanger since it is easier. You may remove the muffler support 


Step 9

Install the second hanger with the 13mm socket. NOTE: the bolt above the muffler will be hard to reach, so using a 13mm ratcheting box-end or adjustable wrench will make it much easier. 


Then tighten the muffler clamp all the way once the hangers are in place. 

Repeat steps 7-9 for the remaining side.  Here’s how it will look. 


If one of the mufflers does not sit centered in the bumper cutout, it is because of the H-pipe. Loosen the 2 H-pipe clamps and the muffler clamp, and then adjust it to your liking. 

Installation Instructions Written By AmericanMuscle Customer Carmine Lomonaco 6.25.2013 

This guide applies to Mustang years: 2005, 2006, 2007, 2008, 2009, 2010 and Submodels: Bullitt, GT, GT500