Sunday, April 26, 2015

The 2008-2014 Subaru Impreza Clutch Weld Failure Fix

The Subaru Clutch Failure Weld Fix

The 2008-2014 Subaru Impreza WRX and STI have a design flaw where the pedal mounting box is spot-welded to the firewall using only a handful of tiny spot welds. The firewall itself is of a weak design and inherently has quite a bit of flex and over time and normal use these spot welds fail from too much stress and the pedals will begin to squeak, creak, pop and eventually the pedals will move away from the firewall when depressed. Once this happens the clutch will no longer properly engage or disengage and the car will no longer be drivable. We have a permanent solution which involves welding the pedal box to the firewall with a continuous seam weld along the circumference of the mounting tab.

The 2008-2014 Impreza WRX and STI firewall has quite a bit of flex. If you press down on your clutch pedal and watch the clutch master cylinder in the engine bay, you can see that it moves forward and backward quite a bit. This excessive flexing stresses the tiny spot welds that hold the pedal mounting box to the firewall. Once these welds start to fail there will be a lot of force applied to the other welds, creating a domino affect that quickly pulls the spot welds out of the firewall one-by-one. This occurs with normal driving and OEM clutches. There is no warranty or TSB fix for this from Subaru, so we have taken steps to solve this issue on our own.

One solution is to prevent the welds from breaking before the issues occurs. We designed a Clutch Master Cylinder Brace (CMCB) which shores up the clutch master cylinder area and greatly reduces the amount of movement there. This will help keep excess stress off the spot welds and can help prevent the spot-weld failure before it happens. We also recommend the use of this brace even if you need to have the firewall welded, as the welding is on the cabin side of the firewall, and the brace reduces flex on the engine bay side. You can read about the brace and purchase it here:

Now once you get to the point of having your spot welds fail, there is only one permanent solution, which is to weld the pedal mounting box tab directly to the firewall using a continuous weld, thus creating a solid fusion between the firewall and pedal box. This not only prevents the pedal box from separating fro mthe firewall but it also gives a more solid pedal pressure and greater clutch feel and engagement.

Our process for the clutch welding fix on the Subaru WRX and STI is to first remove the dashboard. We carefully unplug every clip and sensor, and set the dashboard aside in a safe area to prevent any damage. The steering column must also be dropped to gain access to the areas that needs to be welded. We then prep the interior of the car by draping welding blankets over the interior and taping cardboard to the windshield. This will prevent any sparks or welding spatter from damaging your delicate interior. We then sand down and prep the metal surfaces for welding.

We weld in sections to prevent heat build-up and damage. By the end of our welding process we will have completely welded the pedal-box mounting tab to the interior of the firewall. Creating a permanent fix for the infamous clutch squeak and clutch weld issue on the Subaru Impreza WRX and STI. We then paint the area that was welded and sanded leaving behind an OEM look and to prevent corrosion. The dashboard is re-installed, the steering column replaced, and the interior cleaned. It will be inconspicuous that any welding was ever done at all, you'll just have a solid feeling pedal box and no more popping or squeaking!

We offer this service for all Subaru Impreza, WRX and STI models from year 2008-2014. These are the model years affected by this clutch weld issue. The cost varies depending on what needs to be done so contact us to go over your cars needs and we will be glad to help!

Circuit Motorsports is a performance automotive shop located in Orlando, FL and specializing in Subaru performance, repair, tuning and engine builds.

subaru wrx clutch squeak fix
subaru sti clutch squeak fix
subaru impreza clutch squeak fix
subaru wrx clutch weld fix
subaru sti clutch weld fix
subaru impreza clutch weld fix


  1. Extremely helpful post. This is my first time i visit here. I discovered such a large number of intriguing stuff in your blog particularly its exchange. Truly its extraordinary article. Keep it up. metal welding

  2. I'm located in Los Angeles, southern california area. Do you recommend any shops out here that can fix my problem. The spot welds on my 2008 WRX have broken and the bracket has also broken from my firewall thus restricting me from engaging my reverse gear half the time. I'm in dire need of help and a shop.

  3. Electric resistance welding
    The world owes the invention of electric resistance and spot welding to Englishman Elihu Thomson. This engineer has several patents in the field of spot welding to his name.

    Electric resistance welding consists in assembling by autogenous fusion the parts to be welded under the pressure of two metal parts. Who says welding says heat, with resistance welding the heat necessary for welding is provided by the Joule effect (which is the thermal manifestation of electrical resistance, this heat occurs when an electric current passes through any material conductor) of a current of high intensity and low voltage, passing through the parts to be assembled. Indeed, it takes a lot of amps and little voltage. The application of a forging force makes it possible to ensure the metallic interpenetration.