Download file Free Book PDF Land Rover Overdrive Manual at Complete Installation Manual Series Land Rovers Options Fairey Overdrive. OVERDRIVE UNIT AND SELECTOR MECHANISM. -. Ye |. 17 Gasket, overdrive to transfer box. Dipstick FITTING INSTRUCTIONS. (in). Fairey Overdrive Fitting Instructions. Page history last edited by Stephen Jarman 10 years ago. Download: Fairey Overdrive Fitting

Author: Dilmaran Ninos
Country: Libya
Language: English (Spanish)
Genre: Personal Growth
Published (Last): 2 June 2012
Pages: 299
PDF File Size: 16.17 Mb
ePub File Size: 12.67 Mb
ISBN: 530-7-53669-444-9
Downloads: 56442
Price: Free* [*Free Regsitration Required]
Uploader: Gogar

This is known as the point of maximum power.

Relevant discussion may be found on the talk page. One should refer to the car’s owner’s manual for the proper speed to run at overdrive.

The first unit to be created was the A-type overdrive, which was fitted to many sports cars during the s, and into the late s. Newer vehicles have electronic overdrive in which the computer automatically adjusts to the conditions of power need and load.

The device for achieving an overdrive transmission was usually a small separate gearbox, attached to the rear of the main gearbox and controlled by its own shift lever. Today, most petrol and diesel cars and trucks come with an overdrive transmission because of the benefit to fuel economy. This article relies largely or entirely on a single source. This page was last edited mmanual 13 Septemberat mankal An overdrive consists of an electrically or hydraulically operated epicyclic gear train bolted behind the transmission unit.

Fairey Overdrive Fitting Instructions

Retrieved from ” https: These produce two primary forces slowing the car: For other uses, see Overdrive. These had a direct 1: This allows the vehicle to achieve better fuel efficiency, and often quieter operation on the highway.

Indeed, in modern vehicles this is common. A knob connected to a bowden cablesimilar to some emergency brake applications, was also provided to lock out the unit mechanically. Another British company, the former aircraft builder Faireybuilt a successful all-mechanical unit for the Land Roverwhich is still in production in America today.


The most fundamental meaning is overdrivs of mabual overall gear ratio between engine and wheels, such that the car is over-gearedand cannot reach its potential top speed, i. Given a curve describing the overall drag on the vehicle, it is simple to find the speed at which the total drag forces are the same as the maximum power of the engine.

Under certain conditions, for example driving uphill, or towing a trailer, the transmission may “hunt” between OD and the next highest gear, shifting back and forth. Since the overdrive function, if enabled, could be shifted by simply easing up on the accelerator without depressing the clutch pedalthe action was much like a semi-automatic.

But as more powerful cars appeared, especially during the s, this disparity between the maximum power point and desired speed grew considerably. Overdrive simply adds effective ranges to the gears, mahual overdrive third and fourth become in effect “third-and-a-half” and a fifth gear. By using manua, site, you agree to the Terms of Use and Voerdrive Policy.

In older vehicles, it is sometimes actuated by a knob or button, often incorporated into the gearshift knob, and does not require operation of the clutch. Such add-on overdrive boxes were available from the s to the s for cars and light trucks. Overdrive was widely used in European automobiles with manual transmission in the 60s and 70s to improve mileage and sport driving as a bolt-on option but it became increasingly more common for later transmissions to have this gear built in.

Every cycle of the engine leads to wear, so keeping the engine at higher RPM is also unfavorable for engine fairsy. The purpose of such a gear may not be immediately obvious. The final drive then took this output and adjusted it in a fixed-ratio transmission arrangement that was much simpler to build.


Borg Warner provided the box that was factory-installed between the overddive and a foreshortened driveshaft. In this case, switching it off can help the transmission to “decide”. The higher speeds on the driveshaft and related parts can cause heat and wear problems if an overdrive and high differential gearing or even very small tires are combined, and create unnecessary friction.

Overdrive (mechanics) – Wikipedia

With the early development of cars and the almost universal rear-wheel drive layout, the final drive i. Please help improve this fariey by introducing citations to additional sources.

Also, an electrically operated solenoid would deactivate the unit via a switch under the accelerator pedal providing the equivalent of the kickdown of the automatic. Using overdrive with the main 3-speed transmission in 2nd gear was similar in ratio to 3rd gear, and with the main transmission in 3rd, the overall ratio was fractional i.

The first production vehicle to feature the Laycock system was the Standard Vanguard Saloon. The rotation speed overdrkve comes into effect when the differential gearing is a high ratio and an overdrive is used to compensate. The impetus is to minimize overdrive use and provide a higher ratio first gear, which means more gears between the first and the last to keep the engine at its most efficient speed.

The Volvo version kept the same package size as the J-type but with the updated 18 element freewheel and stronger splines through the planet carrier. If a vehicle is equipped with a bolt-on overdrive e.