Steeda Rear Subframe Alignment Kit IRS Mustang 2015-2023

99% of 100


  • Aids In Alignment Of Sub Frame
  • CNC Delrin Construction
  • Easy Installation
  • No Increase In NVH

Steeda IRS Subframe Alignment Kit for 2015, 2016, 2017, 2018, 2019, 2020, 2021, 2022, and 2023 Mustangs.

The team over at Steeda went hard to work coming up with a simple solution the moment they noticed a lot of people were having issues with their 2015-2023 Mustang's rear subframe being misaligned from the factory. This kit from Steeda guarantees that your Mustang's subframe will be bolted to the same location every time it is lowered, thus eliminating the need for multiple unnecessary alignments!

Features and Benefits:
- Easy Do-It-Yourself Upgrade
- Does Not Require Any Permanent Modifications
- No Additional Hardware Needed for Installation
- Top-Notch CNC-Machined Delrin Construction
- Aids in Perfect Alignment of the Rear Subframe to Chassis
- Absolutely No Increases in NVH (Noise, Vibration and Harshness)
- Made in the USA

Unfortunately, the subframe mounting holes found on the S550 Mustang are very large in comparison to the subframe mounting bolts. Since there is a significant difference in the size of the bolt versus the hole size, the subframe can potentially be misaligned to the left or right up to a 1/2" from the factory. The Steeda IRS Subframe Alignment Kit is made from CNC-machined Delrin. The Delrin sleeves will slide into your subframe mounting holes to fill the extra space left between the subframe mounts and the factory mounting bolts that attach to the rear subframe.

Please Note: Like with many suspension components, CJ Pony Parts highly recommends getting an alignment after installation. Mainly due to the fact that your subframe could have been misaligned from the factory and with it now being squared in the chassis, some adjustments might need to be made.

California Residents: Proposition 65 Warning

Installation Difficulty


Novice skill is required for this installation.

Installation Videos

Video Transcript

Since I recently lowered my 2018 Mustang, time for an alignment. But before I do that, I'm going to make sure the subframe is properly aligned with help from Steeda.

This Steeda IRS Subframe Alignment Kit is going to fit all 2015 through 2022 Mustangs. The way it works, it comes with four of these sleeves. These sleeves are made of CNC-machined delrin, which is a very nice firm material. What these are going to do is go around the bolt that holds the subframe to the chassis. This will make sure the subframe is properly aligned and it'll make it much easier to align the vehicle as well. These are made in the USA and are a fairly easy installation.

For this installation a lift or a jack and jack stands, 3/8" ratchet, 13mm socket, 1/2" ratchet, 21mm socket, a 6" extension, and a Torq wrench.

The subframe bolts are going to be located here and here and then the same thing on the other side. Now this install will of one of two ways. If your subframe is nicely aligned by Ford, literally you can pull the bolt out, put the sleeve in and replace the bolt. Now if the bolt doesn't line up and doesn't go easily, that means the subframe has to adjusted. In that case, you'll actually want to loosen all four and then you can align them as you go.

We're going to start up here with the front. Now what you'll want to do is remove these two bolts first and then remove the subframe bolt because the bracket will have to come off to install the insert. Now you want to be careful when you grab the inserts. They all look very similar but they are different diameters. The thinner diameter goes in the back. The larger one will go up front. Now we'll take the insert and slide it into place. I've put a little grease on these, basically it just helps hold it up in place so we can install the bracket. Like I said, if everything's aligned from the factory, the bolt will go right in.

What you're going to want to do now is repeat the process with the other three inserts and then when we're all finished, we're going to go back and torque each one of them to 129 foot pounds. The Steeda Subframe Alignment Kit, as you saw, is going to be a pretty simple installation. It's going to make sure that not only is the car aligned, the whole subframe is going to be straightened to make for much better alignment. The installation overall is going to take you less than an hour and be back on the road in no time.

Vehicle Fitment

This product will fit the following Mustang years:

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