Mustang Roush V6 Axle Back Exhaust (2011-2012) Installation Instructions

Tools Required:
  • Ratchets & Sockets
  • Torque Wrench
  • Jack & Jack Stands
Install Difficulty:
  • Difficulty
  • Moderate Project
1. The first step in the installaltion your new Mustang Roush 421144 V6 Axle Back Exhaust with Square Tips is to put your Mustang on jacks or a lift. A lift isn't necessary to complete this installation, since you can do this without difficulty by utilizing a hydraulic jack and jack stands.
CAUTION: Make sure the vehicle is on a flat surface. Utilize the parking brake and make sure that the vehicle is cold. DO NOT attempt to remove the muffler while the vehicle is hot.
For removal of the old exhaust and installation of the new one, I utilized a hydraulic jack and jack stands (as pictured below). The jack stands at the front of the Mustang are optional, as there was enough clearance with the rear jack stands only.
Mustang Roush Axle Back Exhaust Install Image
IMPORTANT: Consult your Mustang's manual for proper jacking/lifting instructions.
2. For this installation guide, the driver’s side of the Mustang axle back exhaust is being removed first. Once the vehicle is lifted and properly supported, proceed to loosen the bolt around the clamp using a 15mm socket and ratchet.
Mustang Roush Axle Back Exhaust Install Image
Note: Once the bolt is completely removed, the clamp will remain fastened to the muffler pipe, since it is spot welded. You should not bother to remove the OEM clamp from the muffler pipe, as you will have a new clamp that came with the Roush Muffler.
Mustang Roush Axle Back Exhaust Install Image
Mustang Roush Axle Back Exhaust Install Image
3. Now that the clamp is loose, you are ready to detach the muffler assembly. To do this, just remove hanger #1 from the rubber isolator (see the picture below).
Mustang Roush Axle Back Exhaust Install Image
4. Push the hanger through the rubber isolator. It is a little hard to do, but works best if you grab the rubber isolator with your hand and use your thumb to push the hanger through the hole. It may need a bit of force. The side view (showing where hanger #1 was mounted) and front view pictures are below:
Mustang Roush Axle Back Exhaust Install Image
Mustang Roush Axle Back Exhaust Install Image
This is where hangers #2 and #3 are mounted.
Mustang Roush Axle Back Exhaust Install Image
5. With hanger #1 removed from the rubber isolator and the clamp loose, detach the muffler completely from the Mustang X-pipe or Mustang H-pipe. Pull the muffler assembly away from the mid pipe and detach it completely by pushing the mid pipe towards the floor of the car. The mid pipe has enough play in it so that you are able to move it away from the muffler assembly.
6. With the muffler assembly detached from the mid pipe, you can now slide the muffler assembly towards the front of the car. This allows you to slide the hangers (#2 and #3) off each of the rubber isolators (shown above). You will need to push hanger #2 through the hole with a bit of force. Notice that hanger #3 does not have a knob at the end of the hanger.
7. If you have a lot of trouble pushing the hangers through the rubber isolators while on your back under the car, then you may want to remove the bolts that are holding the rubber isolators to the frame of the car. Both the front and back rubber isolators can be unbolted from the frame. This way you don’t have to be under the car to remove the hangers from the rubber isolators.
8. This will complete the removal of the driver’s side muffler assembly. Follow the same steps to remove the passenger’s side muffler assembly.
9. This installation assumes that you already have the Roush Rear Valance for Square Exhaust Tips installed. This valance is necessary to properly accommodate the Roush Axle Back Exhaust with Square Tips. To get started installing the new exhaust, sort out the parts and split them for the driver's side and passenger's side installations. Notice that the new muffler assembly is much smaller that the OEM muffler assembly. However, the hangers are in the exact same place. Once the square tip is installed, it will also be about the same length as the OEM exhaust.
Mustang Roush Axle Back Exhaust Install Image
10. Slide the new clamp onto the end of the muffler pipe that has the ridge.
11. Next, slide the two hangers that are parallel to each other into the pair of rubber isolators and pull them through the holes. This should be easier than it was to remove them.
Mustang Roush Axle Back Exhaust Install Image
12. With the muffler assembly now hanging from the rubber isolators, line up the two ends that will be connected by the clamp. The two ends should fit together without the clamp, then you can slide the clamp over the joint. Just do not tighten the clamp yet.
Mustang Roush Axle Back Exhaust Install Image
13. Slide the hanger at the far end of the Roush muffler through the rubber isolator near the exhaust. Do not tighten this clamp yet.
Mustang Roush Axle Back Exhaust Install Image
14. Take the exhaust tip clamp (which came in the kit) and slide it around the exhaust pipe prior to attaching the square tip. Then, attach the square tip to the Mustang axle back exhaust, but do not tighten the clamp yet.
Mustang Roush Axle Back Exhaust Install Image
15. Check to see how the exhaust tip lines up with the Mustang rear bumper cover and for clearance around the square tip. You do not want any part of the tip to touch the valance, as the valance might melt when the tip becomes hot.
Mustang Roush Axle Back Exhaust Install Image
Don’t worry about how far in or out the square tip sticks out, as you can adjust that later. For now, you just want the overall placement of the exhaust to be correct. You don’t want it to hang too low or be too close to the valance. There should be equal amounts of clearance the whole way around the tip of the exhaust as well.
It would be a good idea to have someone to help you with this step if you need to readjust any of these pieces.
16. Once you are satisfied with the way it looks, use a torque wrench to tighten the bolts according to the Roush specifications. These are listed on the documentation that is included with the exhaust kit.
However, if you need to adjust the exhaust so that it is centered properly, loosen the bolt and have a helper hold the exhaust tip in place. Then, tighten the clamp as described above.
17. You may want to adjust the square tip for how far it sticks out beyond the valance. Do not go beyond the point where the clamp will not properly hold the square tip. Once you are satisfied with the placement of the tips, you can tighten the bolt.
18. If everything looks good, you are done with this side. If not, loosen the bolts and re-adjust.
Mustang Roush Axle Back Exhaust Install Image
19. Follow the same procedure to install the passenger's side muffler assembly.
19. Once you're done with that, you will have just completed installing your new Roush Mustang V6 Axle Back Exhaust.
Mustang Roush Axle Back Exhaust Install Image