Friday, May 29, 2009
Materials:* 12 Pack Case of Dexron III/Mercon ATF (Costco has Chevron brand ATF for $10.79/ case)* 4' Length of clear Vinyl tubing with a 1" Inside Diameter (available at Lowes or Home Depot for $2/ft or from IPD.)* 1" Hose Clamp* 14mm wrench* 17mm open end wrench* 1" open end wrench* Metal Hangar* 3 1-gallon jugs (or equivalent sized bucket) with quart markings-I used an old antifreeze bottle with the markings already on it and a sight line on the side.* Funnel with ½" outside diameter hose about 1½' long-Used to fill transmission through dipstick hole.Procedure:Start by pulling the dipstick. On 960s, there isn't a dipstick handle. It's easiest to reach under the car from the driver's side and follow the dipstick tube up OR if you have a long ½" extension bar, you can push it into the top of the dipstick and pull it out. Without a ½" bar, push up the dipstick until it's all the way out (and either grab it or let it drop to the floor). Unwind and bend one end of the hanger so it will hook in one or more of the holes on the dipstick. Insert the tube from the funnel into the dipstick tube.you'll probably have to push it in from underneath the car. Pull it up on ramps (if you have them)-the transmission pan is angled in the rear where the drain plug is so this drains more fluid (14mm drain plug). When finished draining, pour what you drained into a premarked bottle and pour that amount of fresh ATF into the tranny (approx. 2qts). Push the car down the ramps onto level ground.Unscrew the top cooler line at the radiator by using a 1" wrench as a counter hold so you don't break the connection. Pull the cooler line out of the 1" brass screw and push it gently aside. With the hose clamp already over the 1" vinyl hose, push the hose over the 1" brass screw and tighten the hose clamp (real tight 'til it begins to form to the sides of the brass nut). Put the end of the hose in the bottle/bucket. Have helper start the engine and let it idle (do not push the accelerator). Fluid will begin to fill the hose and bottle. If the hose is inserted into an antifreeze bottle with a tight fit, push the hose in slightly at the mouth to allow the bottle to vent (otherwise it may expand and explode). Allow 2qts to drain (Tell the helper to shut off the engine just shy of 2 qts as some in the hose will continue to drain when the engine stops). Add two qts of fresh fluid (+or- depending on how much you drained. Repeat until you've drained 8 qts and you see clean fluid. Tip: as you do this, drain each 2 qt run into gallon jugs so you can keep an accurate tally of how much you've taken out relative to the number of empty bottles of fresh ATF you put in. Carefully remove the hose and drain any fluid in it into the jug.note how much and add that amount in fresh fluid. Replace the cooler line and dipstick. Run the engine and shift through the gears. Take it for a short spin to heat up the fluid for measurement. While running the engine in Park, pull the dipstick, clean it off, reinsert it, and pull it again to measure.note the position on the HOT markings. If its low, add a little (keep in mind that if the HOT marking says you're ½ qt low, it won't take ½ to fill it because the ATF from the bottle will expand when heated. If it's overfilled, open the drain plug slightly to get some out. That ought to do it.enjoy your revamped transmission! As a side note: this will not replace all the transmission fluid. The torque convertor will still be full. To completely flush the system you will need to bring it to The Wright Import at
2636 b Business Drive Cumming Georgia 30028. 770-888-0100
Sunday, May 24, 2009
Citroën CX in high position.
Height adjustment is most often achieved by air or oil compression used for the "springs" of the vehicle - when the pressure is varied - the vehicle body rises or lowers.
Height adjustable suspension from 1954 - also high position.
The first instance of a production vehicle with adjustable suspension was on the 1954 Citroën 15CVH. This vehicled featured a self-leveling, height adjustable hydropneumatic suspension. Since this time, these systems have appeared continuously on Citroën models, including the DS and CX.
Height adjustable suspension was banned in the United States from 1974 to 1981, due to the stringent interpretation of passenger vehicle bumper height regulations by the U.S. government agency NHTSA.
Many Modern SUVs use height adjustability as part of active suspension systems to improve the vehicle's versatility on and off road. The Range Rover offered this feature from 1993. New models of the Ford Expedition have a computer-controlled system designed for convenience, which lowers automatically when the doors are unlocked by remote, returns to normal height when the vehicle is started, and (on 4-wheel-drive models), raises when the 4x4 system is engaged.
Some sports cars use these systems to improve the vehicle's handling by lowering the vehicle's height during higher speeds - a current example being the Mercedes-Benz Active Body Control system.
Height adjustable air suspensions are also equipped on "Low-floor" city buses or "Kneeling Buses". This allows the floor to be lowered at a bus stop, to allow handicapped passengers to board more easily.
Aftermarket height adjustable suspension installed on 1964 Chevrolet Impala lowrider.
Adjustable suspensions have become intrinsically associated with lowrider vehicles. The popular image of these vehicles is of one "hopping" on its suspension, or sitting with one wheel completely off the ground.
These systems were initially adapted from the hydraulic pistons, valves and pumps used to adjust the flaps on aircraft. Today however, many aftermarket companies produce parts and equipment specifically designed for lowriders.
In recent years "air bag" systems (not to be confused with the air bag safety device) have been rapidly gaining popularity among car customizers. These air suspension systems use heavy duty custom rubber "bags" to replace the stock shocks and springs, with either a compressor or tank of compressed gas used to raise and lower the vehicle at will.
History of aftermarket systems
Ron Aguirre is commonly accepted as the first person to create a custom car with hydraulically adjustable suspension. In 1959 he scavenged the Pesco pumps and valves from a B-52 Bomber and adapted them to the front suspension of his X-Sonic bubble-topped custom Corvette, allowing him to change the height of the car with a switch on the dashboard.
Traditional height adjustable suspension is controlled by the driver manually. Certain modern layouts allow electronics alone to make this decision without the driver's control, especially if the car lowers at high speed.
The purpose of this system is to provide a soft, comfortable, yet well-controlled ride quality. Its nitrogen springing medium is approximately six times more flexible than conventional steel, so self-leveling is incorporated to allow the vehicle to cope with the extraordinary suppleness provided. France was noted for poor road quality in the post-war years, so the only way to maintain relatively high speed in a vehicle was if it could easily absorb road irregularities.
While the system has inherent advantages over steel springs, generally recognized in the auto industry, it also has an element of complexity, so automakers like Mercedes-Benz, British Leyland (Hydrolastic, Hydragas), and Lincoln have sought to create simpler variants.
This system uses a belt or camshaft driven pump from the engine to pressurise a special hydraulic fluid, which then powers the brakes, suspension and power steering. It can also power any number of features such as the clutch, turning headlamps and even power windows. The suspension system usually features driver-variable ride height, to provide extra clearance in rough terrain.
The suspension setup is referred to as 'oléopneumatique' in early literature, pointing to oil and air as its main components.
There have been many improvements to this system over the years, including variable ride firmness (Hydractive) and active control of body roll (Citroën Activa). The latest incarnation features a simplified single pump-accumulator sphere combination.
The system had one key negative impact on the inventor, Citroën - only specialist garages were qualified to work on the cars - making them seem radically different from ordinary cars with common mechanicals.
Auto manufacturers are still trying to catch up with the combination of features offered by this 1955 suspension system, typically by adding layers of complexity to an ordinary steel spring mechanical system.
Many vehicle systems including aerodynamic properties, headlights, bumpers, and shock absorption from the suspension, are negatively impacted on a conventional vehicle by changes in load.
There is an inherent conflict in suspension design - if the springs are soft, the car will be comfortable but dramatically affected by load. If the springs are hard, the car will be uncomfortable, but less affected by load.
Numerous manufacturers realize this conflict and have pursued different avenues to achieve both comfort and load capacity simultaneously.
In 1954, Citroën introduced the first self-levelling rear suspension, and then in 1955 pioneered self-levelling of all four wheels, using its hydro-pneumatic system. Since then, millions of Citroën cars have been equipped with self-levelling as an unobtrusive, but integral design feature. The Citroën's dashboard includes a five-position lever which allows the driver to select whether the car would travel with the body in a high or low position. When the engine is turned off, the suspension slowly loses pressure until the car rests on the rubber bump stops. When the engine is restarted it rises back to its pre-selected height.
In 1966, Rolls-Royce licensed Citroën's hydro-pneumatic system to fit to the rear axle of the Silver Shadow.
Mercedes-Benz, Ford, GMC, BMW, Land Rover, Scania AB, and Jaguar have each pursued numerous avenues to address this issue, including air suspension and rear axle mechanical devices.
While pleasant, the comfort of the vehicle driver is also important for car safety, both because of driver fatigue on long journeys in uncomfortable vehicles, and also because road disruption can impact the driver's ability to control the vehicle. Early vehicles, like the Ford Model T, with its live axle suspension design, were both uncomfortable and handled poorly.
Automakers often perceive providing an adequate degree of ride quality as a compromise with car handling, because cars with firm suspension offer more roll stiffness, keeping the tires more perpendicular to the road. Similarly, a lower center of gravity is more ideal for handling, but leaves very little vertical space for bump absorption before these disturb the passengers.
Over time, technology has shifted this curve outward, so that it is possible to offer vehicles that are extremely comfortable and still handle very well, like the Citroën DS, or vehicles with excellent handling that are also reasonably comfortable, like the BMW 5-Series.
Technology from the latter half of the 20th Century is not the only means to achieve ride quality - massive weight coupled with very soft suspension settings is also an option - as seen on the Rolls-Royce Silver Cloud and the Cadillac in the 1950s and 1960s, which weighed over 5,000 lbs. The downside is that massive weight also contributes to poor fuel efficiency. In the United States, the Corporate Average Fuel Economy standard effectively prohibits the return to a passenger vehicle fleet of what now appear to be comically oversized cars from the 1950s and 1960s. In most of the rest of the world, the high price of gasoline effectively prevents most motorists from using massively heavy cars.
Load bearing also interferes with ride quality - the suspension settings are very stiff so the vehicle doesn't change pitch when loaded - most trucks thus do not ride particularly comfortably. In passenger vehicles, self-leveling suspension has been introduced to counteract this effect.
Road construction quality and maintenance have a direct impact on ride quality in vehicles. In jurisdictions where all roads are as smooth as pool tables, the passengers are undisturbed already and the vehicle can be optimized for a higher degree of handling. In most industrialized countries, as well as in many development countries, pavement condition is scanned on road network level using laser/inertial road Profilometers. The Profilometer records road geometry and condition while driving at highway speed. Results from Profilometry can be used to design an optimal geometric pavement repair, eliminating all long wave unevenness, roughness, erroneous cross slope magnitudes and undesired cross slope variance, with the least road grinding and paving efforts. The outcome is a surface with superior ride quality.
Air bag or air strut failure is usually caused by wet rot, due to old age, or moisture within the air system that damages it from the inside. Air ride suspension parts may fail because rubber dries out. Punctures to the air bag may be caused from debris on the road. With custom applications, improper installation may cause the air bags to rub against the vehicle's frame or other surrounding parts, damaging it. This is why we recommend replacing your air suspension system with one of our conversion kits.
Compressor failure is primarily due to leaking air springs or air struts. The compressor will burn out trying to maintain the correct air pressure in a leaking air system. Compressor burnout may also be caused by moisture from within the air system coming into contact with its electronic parts.
In Dryer failure the dryer, which functions to remove moisture from the air system, eventually becomes saturated and unable to perform that function. This causes moisture to build up in the system and can result in damaged air springs and/or a burned out compressor.
Air suspension is a type of vehicle suspension powered by an engine driven or electric air pump or compressor. This pump pressurizes the air, using compressed air as a spring. Air suspension replaces conventional steel springs. If the engine is left off for an extended period, the car will settle to the ground. The purpose of air suspension is to provide a smooth ride quality and in some cases self-leveling.
With a "leg up" on other companies, GM used its experience with commercial busses' air suspension to introduce systems for its car lines, beginning with the 1958 model year. Air bags at each wheel replaced the standard coil springs, and had sensors to keep the car level under load and in turns. It was too slow to react in sudden maneuvers, however.
Period reviews rated the air suspension somewhat superior in ride quality, but not dramatically. Some reliability issues plagued these systems, as well. Thus, as an option, air suspension was short lived in that era.Vehicles that use air suspension today include models from Maybach, Rolls-Royce, Lexus, Mercedes-Benz, Land Rover/Range Rover, Ssang-Yong, Audi, Subaru, Volkswagen, and Lincoln and Ford, among others.
The air suspension designs from Land Rover, SsangYong, Subaru and some Audi, VW, and Lexus models, feature height adjustable suspension controlled by the driver, suitable for clearing rough terrain. The Lincoln Continental and Mark VIII also featured an air suspension system in which the driver could choose how sporty or comfortable they wanted the suspension to feel. These suspension settings were also linked to the memory seat system, meaning that the car would automatically adjust the suspension to the individual driver. The control system in the Mark VIII also lowered the suspension by about 25 mm (1 inch) at speeds exceeding about 100 km/h (60 mph) for improved aerodynamic performance. Unfortunately, however, these systems turned out to be unreliable and in many cases ended up being retrofitted with aftermarket replacements or conventional steel coil springs.
In addition to passenger cars, air suspension is broadly used on semi trailers and buses, which are both transportation sectors that helped pioneer the use and design of air suspension. An unusual application was on EMD's experimental Aerotrain.
Over the last decade or so air suspension has become extremely popular in the custom automobile culture: street rods, trucks, cars, and even motorcycles may have air springs. They are used in these applications to provide an adjustable suspension which allows vehicles to sit extremely low, yet be able rise to a level high enough to maneuver over obstacles and inconsistencies in the roadways (and parking lots). These systems generally employ small, electric or engine-driven air compressors which sometimes fill an on-board air receiver tank which stores compressed air for use in the future without delay. High-pressured industrial gas bottles (such as nitrogen or carbon dioxide tanks used to store shielding gases for welding) are sometimes used in more radical air suspension setups. Either of these reservoir systems may be fully adjustable, being able to adjust each wheel's air pressure individually. This allows the user to tilt the vehicle side to side, front to back, in some instances "hit a 3-wheel" (contort the vehicle so one wheel lifts up from the ground) or even "hop" the entire vehicle into the air. When a pressure reservoir is present, the flow of air or gas is commonly controlled with pneumatic solenoid valves. This allows the user to make adjustments by simply pressing a momentary-contact electric button or switch.
The installation and configuration of these systems varies for different makes and models but the underlying principle remains the same. The metal spring (coil or leaf) is removed, and an air bag, also referred to as an air spring, is inserted or fabricated to fit in the place of the factory spring. When air pressure is supplied to the air bag, the suspension can be adjusted either up or down (lifted or lowered).
For vehicles with leaf spring suspension such as pickup trucks, the leaf spring is sometimes eliminated and replaced with a multiple-bar linkage. These bars are typically in a trailing arm configuration and the air spring may be situated vertically between a link bar or the axle housing and a point on the vehicle's frame. In other cases, the air bag is situated on the opposite side of the axle from the main link bars on an additional cantilever member. If the main linkage bars are oriented parallel to the longitudinal (driving) axis of the car, the axle housing may be constrained laterally with either a Panhard bar or Watt's linkage. In some cases, two of the link bars may be combined into a triangular shape which effectively constrains the vehicles axle laterally.
Often, owners may desire to lower their vehicle to such an extent that they must cut away portions of the frame for more clearance. A reinforcement member commonly referred to as a C-notch is then bolted or welded to the vehicle frame in order to maintain structural integrity. Specifically on pickup trucks, this process is termed "notching" because a portion (notch) of the cargo bed may also be removed, along with the wheel wells, to provide maximum axle clearance. For some, it is desirable to have the vehicle so low that the frame rests on the ground when the air bags are fully deflated.