PFF76-923BLK Upper Gearbox Mount Insert is an affordable and easy-to-fit bush insert made from our Black 95A Durometer high-performance material, which works to significantly stiffen the OEM upper gearbox mounting for performance on the race circuit or the rally stage. This reduces twist of the engine under acceleration and during gear changes, giving the pedals a more direct feel, as well as reducing wheel-hop and letting you get the power down that little bit quicker. We recommend fitting PFF76-923BLK alongside the other Yaris GR powertrain inserts (PFF76-920BLK & PFF76-925BLK), as they perform much more effectively as a full set. There will be an increase in NVH when fitting Black series inserts.
