The air-lock differential is a direct-replacement differential. It can be used either as a conventional differential or as a 100 % locked one — whether front or rear. When engaged, it locks both half-shafts and thus transmits the driving force to both wheels 50 % : 50 % for maximum traction. The locking mechanism is controlled by the driver via a button on the vehicle’s dashboard. The front lock may be activated when driving over slippery surfaces with reduced grip and de-activated when driving on surfaces with good grip, in order to achieve optimal cornering control. For safety reasons, the front lock cannot be used unless the rear one is already activated.
 
What the kit includes
The kit contains everything necessary for installation of the differential lock, plus instructions for the work. Installation at an authorised service centre is recommended. 
 
The supplier provides a 3-year warranty.
 
Technical information:
Weight: 15 kg 
Dimensions: 28 × 28 × 28 cm 
 
Compatible models (Rover)
 
Range Rover (1993-96) 24 spl — front diff lock, rear diff lock 
Discovery (1993-96) 24 spl — front diff lock, rear diff lock 
Discovery Series II (all models except P38A, after 2002) — front diff lock, rear diff lock 
Defender 110, 130, County (after 1993, all models with 24 splines) — front diff lock 
Defender 110, 130, County (after 2002, all models with 24 splines) — front diff lock 
Defender 90 (after 1993, all models with 24 splines) — front diff lock 
 
How it works
Since the lock is activated by compressed air, a compressor or another source of compressed air is required. The compressor is activated by the driver via a dashboard button. The pressure in the expansion tank is monitored by a regulator in the working range of 5.9 bar to 6.9 bar. When the air-lock button is pressed, the pneumatic valve opens and allows compressed air to reach the differential via an air line connecting them.