4 HA LSD Torque Biasing diff, specially altered & adapted by ourselves to fit  Aston Martin DB2/4 MkII 4 HA axle, also fits Jaguar Mk2, 240 & 340 with solid axle.

This diff has most of the advantages of a plate LSD, it has the advantage of being quiet - instead of being noisy like a plate type diff, but if one rear wheel lifts fully of the ground the diff wont lock, so no good for a competition car - see Footnote

This is a Torsen Gleason gear type diff, which contain no noisy plates rubbing together, it also last a lot longer because of this, a description of which is below:

The ATB Helical LSD differential sold by Four Ashes for Aston Martin models with live 4HA axle. A direct replacement for the standard Salisbury open differential, the ATB Helical LSD differential transforms your car’s performance.

Unlike a conventional plate-style limited slip differential, the Aston Martin ATB Helical LSD differential relies on gears rather than clutch plates for its operation. That means it is much smoother & quieter in operation.

The Four Ashes modified ATB Helical LSD differential never locks harshly with a set pre-load of wheel slip across the driven axle, like a conventional LSD. Rather, the  ATB Helical LSD differential automatically biases the torque away from the spinning wheel across the axle, to a constantly varying degree, and never locks.

The ATB Helical LSD differential has many benefits over a standard open differential, including maximising traction and minimizing wheelspin, eliminating torque steer and snatching in front wheel drive cars compared to conventional LSD units, and a maintenance-free design which retains the standard EP90 oil lubrication.

Footnote

We also sell plate type LSD's that are quiet, these are not Power Lock diffs as originally fitted, they are much more advanced !!

Both types of LSD listed above are available for Solid or Independent diffs, specify which when enquiring.