Allston Auto Repair

Subaru’s symmetrical all wheel drive gives confident traction in New England weather, yet it is picky about one thing that many drivers overlook. The system expects all four tires to roll at the same speed. When diameters do not match, even by a small amount, the center differential and clutches work harder than they should. Over time, that stress shows up as binding in tight turns, warning lights, or expensive driveline wear. A few simple checks each fall can prevent that headache before winter hits.    Why Equal Rolling Diameter MattersYour Subaru splits torque front to rear through a center differential or an electronically controlled clutch pack, depending on the model. Those parts allow a small difference in rotation while cornering, then return to a balanced speed on straight roads. If one tire is taller, it must travel farther on every revolution, which forces the center unit t ... read more