The 034Motorsport Upper Dogbone Mount Insert (patent pending) recommended for any MkV/MkVI Volkswagen Golf/GTI/R/Jetta/GLI and 8P Audi A3 & 8J Audi TT/TTS/TTRS using any dogbone mount and dogbone mount insert, and is strongly recommended when using the OEM dogbone mount and a lower insert. Aggressive driving that causes violent drivetrain movement, such as burn-outs that induce wheel-hop, will cause the upper and lower dogbone mounts to exert a bending moment on the dogbone mount arm, causing it to bend, and in some cases fail. When this failure occurs, the bottom of the engine is unconstrained and the engine will cause damage to other components in the engine bay. The 034Motorsport Upper Dogbone Mount Insert eliminates these bending forces, allowing the dogbone mount to perform as designed during these violent events.
Any dogbone mount combined with a lower dogbone mount insert dramatically improves the feel and responsiveness of the drivetrain during spirited driving. However, this combination of modifications has revealed a scenario that applies forces to the dogbone mount arm that it was not designed for. These forces have been seen to break OEM dogbone mounts. While billet aluminum aftermarket dogbone mounts have proven to be significantly stronger than OEM and resist this bending force, adding the upper insert removes this bending force while evenly distributing forces on both the upper and lower dogbone mount pucks, reducing excessive wear on the lower puck.
The lower dogbone mount insert limits compliance of the lower dogbone mount puck by filling large voids in the puck. During normal and spirited driving, this reduction in compliance results in more direct transitional response of the drivetrain to accelerative and decelerative forces. The driver feels more direct throttle response through the drivetrain without introducing a significant amount of NVH.
However, violent drivetrain shocks, such as burn-out induced wheel-hop, introduce additional forces that can cause damage to the dogbone mount arm. In these violent events, the lower puck motion is limited by the dogbone insert, but the upper puck in unconstrained and is free to move forward.
This means that the entire puck assembly rotates forward at an angle towards the front of the car. Because the dogbone mount arm is clamped into the puck assembly, the rotation of the puck assembly generates a bending moment applied to the dogbone mount arm that it was not designed for.
Our engineering team developed the 034Motorsport Billet Upper Dogbone Mount Insert to solve the issue. This insert slips into the front void of the upper dogbone mount puck, limiting the forward motion of the upper puck to match the limited forward-motion of the lower puck with the lower insert installed. The result is an upper and lower insert package that eliminates the rotation inside the puck assembly during extreme drivetrain shocks, and keeps the forces acting on the dogbone arm in the direction the arm was designed for. Subsequent testing showed no signs of bending or stress in the dogbone mount arm with both the upper and lower dogbone mount inserts installed. Watch the demonstration video below to see how the dogbone mount pucks move with just the lower insert, and the upper and lower insert combined.