Range Rover Classic Diff Lock Selector

Range Rover Classic Diff Lock Selector

Introduction
The 4 sp gearbox, fitted to all manual Range Rovers from 1970 to 1983, has a transfer box which is integral with the gearbox assembly and is, therefore, inseparable from it.

The 5 sp manual gearbox, introduced in July 1983, has a separate transfer box as follows:

• 1983 to approx. 1984 models are fitted with Land Rover's LT230R unit, which is gear-driven and incorporates a manually selectable diff-lock.
• 1984 (approx.) to Oct 1988 models are fitted with Land Rover's LT230T unit, similar to the LT230R but with taper bearings on the intermediate shaft instead of the previously used needle roller bearings.
• Oct 1988 onwards models are fitted with a Borg Warner chain-driven transfer box, incorporating a viscous differential lock.

Automatic models also have separate transfer boxes, as follows:

• 3-sp autos are fitted with either the LT230R or LT230T transfer boxes.
• 4-sp autos to Sept 1988 are fitted with the LT230T transfer box.
• 4-sp auto vehicles from Oct 1988 onwards are fitted with the Borg Warner chain-driven transfer box.

This section includes fully reconditioned transfer gearboxes, as well as the components associated with the transfer box, such as the speedo cable. Also included is the parking brake, since this operates on the rear of the transfer box rather than the rear wheels, as is conventional.

As with the main gearbox, we have only listed a limited selection of internal components, because repair is rarely as cost-effective as replacement with a recon unit.

Unit Identification
Identification of the transfer box fitted to your Range Rover is fairly straightforward:

• 4-sp. All 4-sp manual vehicles have an integral transfer box.
5-sp/LT230R. LT230R transfer boxes fitted to 5-sp vehicles have a serial number (located on the rear lower face of the transfer box) which begins 15D.
• 5-sp/LT230T. LT230T transfer boxes fitted to 5-sp vehicles have a serial number beginning 27D or 28D.
• 5-sp/Borg Warner. Vehicles fitted with the BW transfer box are easily identified from the transfer gear lever inside the car, which has a simple fore & aft plane instead of the H-gate of earlier vehicles.
• 3-sp Auto/LT230R. LT230 transfer boxes fitted to 3-sp auto vehicles have a serial no. beginning 14D.
• 3-sp Auto/LT230T. LT230T transfer boxes fitted to 3-sp autos have a serial no. beginning 26D.
• 4-sp Auto/LT230T. 4-sp auto vehicles with the LT230T transfer box have a serial no. beginning 28D.
• 4-sp Auto/Borg Warner. These vehicles are easily identified by the transfer gear lever inside the car, which has a simple fore & aft plane instead of the H-gate of earlier vehicles.

Gear Ratios
The high-gear ratios of the transfer boxes are as follows:

• LT230R
• 14D (Auto) 1.003:1
• 15D (Manual) 1.192:1
• LT230T
• 26D (Auto) 1.003:1
• 27D (Manual) 1.192:1
• 28D (Manual & Auto) 1.222:1
• Borg Warner (Manual & Auto) 1.206:1