The Model DS ROAMERDRIVE is an upgraded version of our model DX first introduced in 2006. The upgrades on the DS model include a more open front-end architecture that enables oil shared with the transfer case to be circulated more efficiently. An Archimedes screw on the main shaft retains oil behind a ‘dam’ in the front cover to ensure efficient lubrication at high speeds and on steep inclines. A crush washer on the nose of the overdrive provides bearing preload on all variations of transfer case.
Other than the use of epicyclical gear technology, the DS has little in common with other designs of overdrive sold for five speed Land Rovers in the past. The overdrive has no electrical components or cone friction clutches and no dedicated oil sump. It is a very compact unit that shares oil with the transfer case and does not interfere with exhaust pipes or other fittings on the Land Rover.
The DS overdrive can be fitted to any five-speed 90, 110 or 130 model Defender Land Rover from the time of introduction in 1985 up to and including the TD5 model. Apart from the specific exceptions listed below, the DS-B overdrive will fit all models of 90, 110, and 130 DEFENDER type Land Rover with the following motors:
2.5 Diesel Military
The DS model can also be fitted to vehicles with popular replacement engines such as the International 2.8 and TD5 engines that have been modified to produce more power. Some restrictions apply to such modified vehicles see installation instructions ».
The overdrive takes about three hours to install and is supplied as a complete kit that includes everything required to make the installation apart from lubricating oil.
The overdrive is engaged using a simple hand lever. The lever is conveniently located on the centre console immediately adjacent to the Hi/Low range knob.
The DS-B will not fit in the following cases:
- Models fitted with four speed gearboxes.
- Models fitted with 230 transfer case suffix A and B found on early 90 and 110 models. You would need to fit the later suffix transfer case used up to the TD5 model.
- Models that have been retrofitted with Discovery transfer cases.
- Models that have been retrofitted with six speed gearboxes. You would need to fit the suffix transfer case used up to the TD5 model.
DRIVING WITH A DS ROAMERDRIVE
To engage the overdrive when on the highway, wait unit you are travelling at about 50 mph (80 kph) in fifth gear. Depress the clutch and move the actuating lever forward exactly as you would when changing gear. When the clutch is released the engine RPM will drop by 28% and the noise level in the cab of the Land Rover will drop significantly. As changing traffic and gradient dictate, you can engage and disengage the unit.
In urban driving you can engage and disengage in third and fourth gear to get the best working ratios. You will find for example that it is much easier to engage the ROAMERDRIVE in fourth gear than to shift the main gear lever into fifth.
In off road conditions when driving in low range the overdrive is useful for raising the ratios making it unnecessary to engage and disengage the high range lever.
Driving a Land Rover with a Global Roamer overdrive is a pleasant experience as it is possible to have a normal conversation at relatively high motoring speeds
The inclination to drive faster with the overdrive negates considerable fuel savings to be had if one retains one’s original driving patterns. Our experience shows that drivers who use the ROAMERDRIVE at moderate speeds will save up to 15% on their fuel costs. The long-term saving of less wear and tear on engine and drive line components are also considerable. Bear this in mind and your overdrive will pay for itself quickly.