The Aston Martin Vantage V8 uses a mechanical limited slip differential (LSD) that is more complex than an open differential. The LSD limits the independent movement of the driven wheels to prevent over slipping and enable better control of the large torque delivered to the wheels. Various components in the differential were analyzed for surface roughness, with measurements ranging from 161nm for a smooth disk to 6.17μm for a friction disk. The differential components help transfer torque from the engine to the wheels efficiently while remaining durable through features like cooling fins, seals, and a lightweight but strong aluminum alloy casing.

1. Aston Martin Dissection - Differential
Isabelle Yeung, Henry Oloyede, Marie Taylor,
Georgina Fisher, Lizzie Nuttall, Adam Vaslet
Limited Slip Differentials (LSD)
The Aston Martin Vantage V8 makes use of a
mechanical limited slip differential
(LSD), which is more complex than the more
common open differential and enables more
control of the large amount of torque being
delivered to the wheels.
The LSD limits the amount of independent
movement of both driven wheels, preventing
over slipping of one wheel.
Surface Roughness
• Various components had their surface roughness analysed using a Alicona machine:
• Friction disk: 6.17µm
• Smooth disk: 161nm
• Curved surface for bevel gears to sit on: 383nm
• Concave spring: 1.16 µm
• Smooth disk has deposits on it from rough disk suggesting a softer material
• The pump is used to circulate the gear oil within
the differential and gearbox.
• The tolerance on the gears is so fine that the
teeth wear away the inside of the pump.
• There are many seals in the pump to ensure the
lubricant remains in the casing and moves
through the gears effectively.
• 12 bolts are used in order to withstand the huge torque from the engine.
• The thick ribs provide increased strength to the casing.
• Very few signs of wear can be seen.
• Several cooling fins in order to transfer heat away.
• Corrosion coating on all of the outside.
• The casing is cast from AlSi7Mg Alloy, making it lightweight but strong.
• In spiral bevel gears there is less sliding
between teeth and a greater meshing surface
area allowing more efficient operation.
• The two roller bearings allow the differential
housing to rotate within the differential and
gear box casing are cone shaped – this allows
the axial forces transmitted from the
crankshaft to the pinion to cancel out.
• Makes use of a clutch pad system.
• Uses concave friction disks sat on the outside
surface of the differential housing for the pinion
and side gears.
• Produced the same effect of keeping the clutch
tight even after wear.
• Disks have a lower weight than springs, are
easier to machine, and have fewer stresses
acting directly on the gears, instead acting
on the gear housing.
Rough disk Profile of gear housing Smooth diskRough disk graph – shows surface roughness of 6.17µm