Add to Cart Quaife Fiat Siena Quaife Atb Helical Lsd Differential, Qdh2K-20 $841.12 Quaife ATB Helical LSD differential for the Fiat Siena is a direct replacement for the standard Fiat Siena open differential. The Quaife ATB Helical LSD differential transforms your car’s performance. Unlike a conventional plate-style limited... $841.12 Add to Cart