The gearbox, or transmission, transmits the rotational force – the so-called rotational torque – from the car motor to the wheels. Depending on the vehicle’s driving conditions, it can transmit all or part of the torque. A car going uphill must have a lower gear than a car racing on a smooth highway. In a lower gear, more torque is transmitted to the wheels. And this is necessary when the car is moving slowly because it’s heavy. Higher gears are suitable for faster driving.
When an automatic transmission is used, the driver has no clutch pedal at his foot. Instead, a torque converter paired with a planetary gear automatically disconnects the motor from the driveshaft when driving conditions require it to change gears. After the gearing has been changed, the drive shaft is connected again. Once the driver has put the control lever in the operating position, the automatic gearbox mechanism will select the right one according to the driving conditions at that moment.
If a manual gearbox has a simple design, the automatic one has more units and assemblies, which in turn affects the cost of its manufacture, repair and operation. However, such a gearbox is more convenient to use, especially when driving in the city, because it does not require constant switching on/off the clutch. In this way, human involvement in the automatic unit is minimized.
Also, today the customer can choose from several types of automatic transmissions: hydro-mechanical gearbox (conventional “automatic”), manual transmission with two clutches, robotic gearbox and CVT.
Each of these types of transmissions has its pros and cons. Among the advantages is that it is easy to use (no need to constantly engage the clutch), it has no risk of overloading the motor (the automatic gearbox itself selects the best moment to shift to a higher or lower gear). Also, it has shortened time between the lower to higher and back shifts without loss of motor power.
However, such type is known for expensive repair and maintenance, a heavyweight of the unit (compared to a manual gearbox) as well as relatively low vehicle injectivity (most typical for hydraulic transmissions). You are also unable to tow the vehicle with a flexible or rigid coupling (only with a tow truck).
4r70w rebuild cost
This modification of the box was installed on Ford brand cars with sedan bodies. The unit was created by two companies – Ford and Mazda – in 1995, production of the transmission continued until 2006.
The 4R70W (AODE) transmission has a simple design, which guarantees the unit reliability and long service life. For example, maintenance of the automatic unit is not required. For installation on cars with powerful engines, the transmission has been upgraded. The volume of oil used is 10 liters. The number of solenoids has been increased. The main task of these parts is to guarantee the normal functioning of the lubricant cooling complex. Clutch, friction, disks are made of heavy-duty alloy. This fact guarantees the box resistance to premature wear and breakage.
The 4R70W (AODE) AKPP is characterized by a high level of serviceability. Repair or replacement of this transmission modification can be carried out at car dealerships specializing in working with automatic transmissions of this type.
For a well-built transmission with a good converter, you can expect to pay about $3000-$3500 to have it done right. Also, you will pay $1800-$2200 for stock rebuild done right. Or you can do it yourself with the help of 4r70w complete rebuild kit .
How to build a bulletproof 4r70w?
Making cars bulletproof has become a profitable business.
In the beginning, all interior elements are removed:
- interior trim;
- electrical wiring;
- car seats.
Then, all doors and other hollow body parts (e.g. poles) are cut so that they can be “stuffed” with materials necessary for a car reservation. Depending on the level of protection, the doors and posts are reinforced with steel sheets and a combination of ballistic nylon and kevlar, a material similar to that found in bulletproof vests. If the doors become too heavy, a third hinge is added.
Thermal insulation and rear partitions get steel coating, but the floor and ceiling are covered with ballistic fabric. The base bumpers, which absorb energy during heavy collisions, are reinforced so that the armoured vehicle can break through an improvised roadblock without damaging the radiator.
Reinforced armour plates are used to protect the fuel tank and transmission components, which can reliably protect against a direct hit by bullets, small-calibre projectiles and mine fragments.
Even the lightest armor will add at least 500 pounds of extra weight to the large sedan. If the level of protection is increased, the weight of the vehicle will also increase. If the standard weight of a large sedan is increased by 1300 pounds, the chassis, brakes, and sometimes the transmission must be strengthened.
To maintain controllability, the armored car is equipped with reinforced shock absorbers and springs, and if necessary, air springs. Most engines in large sedans have enough power to cope with the extra weight of the car, so the engine is chipped, pumped or changed to a more powerful, only on special request of the customer.