Range Rover Classic LT-230 Transfer Case Conversion

A Brief Overview:

     As more and more people have began to purchase Land Rovers and Range Rovers in the interest of using them for more serious off-road adventures, the weak spots of the vehicles become readily apparent. In this article we will address the conversion of the 1989-1995 Range Rover Classic conversion from the Borg-Warner transfer case to the Land Rover LT-230 transfer case.
     The Borg-Warner case is a chain-driven transfer case which relies on a viscous coupling to engage the transfer case into “locked” mode in which full power is sent to both front in rear axles. In comparison, the Land Rover LT-230 is a gear driven transfer case which utilizes a locking center differential in order to transmit full power to the front and rear axles. This design, makes for a much stronger and more reliable transfer case. In fact as the LT-230 cases are becoming more readily available, enthusiasts of other marques are adapting these transfer cases to high-torque and horse power motor and transmission setups, a testament to their strength.

Obtaining a Land Rover LT-230 in North America:

     The Land Rover LT-230 transfer case was available in the 1988 Range Rover Classic before the switch was made in 1989 to the Borg-Warner unit, as well as being available in all 1994-1999 Land Rover Defenders and Land Rover Discoveries.

Our 1995 Discovery Donor

     For the Range Rover Classic swap, the ideal donor candidate would be the1994-1999 Series I Land Rover Discovery with the ZFHP22 automatic transmission, the same one used in all the 1989-1995 Range Rovers. Ideally when one obtains the LT230, they will want to also make sure to retain the LT-230 shifter linkage and parking brake drum, cable and the frame mounts as well. Some also chose to obtain the center console pieces from a 1988 Range Rover Classic, which used the LT-230 transfer case, and had provisions for a light which would illuminate when the center differential lock is engaged.

Removing the Borg-Warner Case:

     First thing you’ll want to do is of course disconnect your vehicles battery as a safety precaution, because the engine/transmission/transfer case will be rotated about the engine mounts and if rotated too far with a connected battery and the right cable being pulled taught, the starter might try to start the engine, and you do not want this. So once you’ve pulled the battery cable and made the proper safety provisions (jack stands, lift, wheel chocks, etc...) you’ll want to drain the Borg-Warner and disconnect the parking brake cable as well as removing the front and rear drive shafts. You will also need to remove the exhaust at the manifolds. Once you have done this you will want to place a transmission jack under the transfer case for support and then unbolt the transmission and transfer case mounts from the frame. Once this has been done you will lower the transmission jack and unbolt the Borg-Warner transfer case from the transmission and gently work it off of the transmission output shaft. Also do not discard the Borg-Warner’s mechanical speedometer cable, you will re-use this on the LT-230.

Borg-Warner Transfer Case Removed

Installing the Land Rover LT-230 Transfer Case:

     Once you have removed the Borg-Warner transfer case check the transmissions out put shaft for any excessive wear. If it appears worn you will want to obtain a new one.

The LT-230 Input Seal

     Also while the Borg-Warner case is removed you will want to replace the transmission output seal and remove the lockout solenoid. To do this, simply unbolt the cover plate, remove the solenoid and re-install the cover plate, making sure to use the appropriate sealant.

LT-230 Lockout Solenoid

     You will also need to remove the LT-230’s electronic speedometer unit if your LT-230 came from a Discovery and replace it with the mechanical unit you removed from the Borg-Warner case. Also make sure to install a new input seal on the LT-230 before it is installed, as well as check for any play in the outputs, as this could be indicative of a bearing preparing to let go.

LT-230 Output

     This is also a good time to replace the rubber transmission and LT-230 mounts. Also if you bought a used LT-230, make sure to have emptied the case before you try to install it, the lighter the case is the easier it is to install. So now that the LT-230 is prepped you’ll want to raise it into position and CAREFULY slide it on to the output shaft of the transmission until the faces mate, and then bolt it in place to the back of the transmission.

LT-230 Installed

     Take great care to make sure the shifter linkage makes it through the transmission tunnel. You may need to make some modifications to the tunnel/console to make the shifting linkage fit and allow for full unobstructed movement of the shifter. Next bolt the transmission and LT-230 back in place to the frame and attach the parking brake drum cable to the parking brake. You may have to adjust the cable

Another view of the installed LT-230

accordingly later on. Now here comes a critical part, the drive shafts. Some chose to use the front and rear drive shafts from a 1988 Range Rover which came with an LT-230 or U-jointed Discovery drive shafts, since they can be had for cheap, but if one is looking to build a lifted trail capable rig, we would recommend going ahead and installing some heavy duty custom drive shafts. Once everything is installed, and back together, and making sure to fill the LT-230 with gear oil, it’s time to take the truck out for a drive, testing the shifter linkage and listening for any unusual sounds. Some gear whine and clunking when shifting is normal from these cases, especially a used one, but anything abnormally loud or harsh should be investigated.

Please E-mail us with any corrections or information you might want to share regarding this conversion.

The information contained within these tech pages are for information and reference purposes only. The owners of RoverUnited and providers of the information cannot be held liable for any accident, damage or injury incurred while trying to perform any of the modifications or installations detailed on this site. If you are uncomfortable performing a task, contact a professional Rover shop, they will be more than happy to help you.