The change has seen the IS F gain a two second improvement in lap times around Japan's Fuji Speedway and joins other convenience and design feature upgrades in face-lifting the model.
The Torsen LSD redistributes the torque that is lost when a wheel loses traction during cornering, without limiting engine output. New differential oil has also seen the unit perform more smoothly as well as making it quieter.
IS F upgrades also include a revised satellite navigation unit with improved route guidance, functionality and map view.
The 14-speaker Mark Levinson audio system has been upgraded too and now features a new USB input for iPods along with new software to allow selection of tracks via the vehicle's touch screen navigation unit.
Interior revisions see the inclusion of folding rear head restraints, F logo on the ultra-thin card key, and a new steering wheel and centre cluster design.
The new steering wheel has added colour trim in the lower section of the rim and new "overcast" stitching pattern to provide a neater finish to the leather wrapped steering wheel.
The centre cluster has improved audio switches, as well as a new facia around the navigation system and air conditioning unit.
In addition, Lexus has redesigned the moonroof controls with seesaw-type switches in lieu of a dial-type switch, for greater ease of use.
"IS F has continued to outsell its allocation month on month, with the upgrades ensuring its sustained popularity," said Lexus Chief Executive, Mr John Roca. "The adoption of a mechanical LSD will deliver a greater drive experience on the road and on the circuit. IS F has been of critical importance in shifting Lexus' brand perception."
For a full review of the current Lexus IS F, click here.