As you know, any engine needs cooling. But few people know that not only the motor, but also the gearbox is exposed to thermal stresses. Moreover, the machine often heats up. For this purpose, an automatic transmission oil cooler is installed on many machines. Volvo is equipped with it from the factory. What is this element, how to install it and what are its features? We will talk about this in our article today.
Features of the automatic transmission cooling system
Any gearbox has oil. However, in automatic, unlike mechanics, it is designed to transmit torque. Automatic transmission grease is more liquid and has the ATP mark. In mechanics, an almost jelly-like fluid with a viscosity of 85W90 (or so) is filled in, in which a black shade predominates. Why are there such differences? It's all about the principle of the box. The oil in the mechanics is filled only in the sump. Gears during rotation are dipped into this bath and thus lubricated. In automatic transmission, everything is different. Here, a torque converter (or “donut”) is used as a clutch. Inside it there are two impellers. They interact with each other due to the directed flow of oil. That is, the lubricant performs the function of transmitting torque.
Accordingly, the liquid is constantly in motion and heats up. But overheated oil can damage the box. It is necessary that the ATP-liquid be heated to 75-80 degrees. Already at 100, changes in viscosity and other characteristics begin. As a result, the automatic transmission resource is reduced by 2-3 times.
Why do I need an automatic transmission oil cooler?
As we said earlier, the fluid in the box is constantly heated. And in order to prevent overheating, a heat exchanger is needed. It is the radiator that keeps the operating temperature, preventing overheating of the oil and the box.
Where is?
Depending on the design features, the oil cooler automatic transmission can be located in the box itself (in the pallet) or be integrated into the main heat exchanger. The latter scheme is more thoughtful and universal.
However, this method of placement has disadvantages. For example, if a breakdown of one of the two heat exchangers in the housing occurs, antifreeze and oil mix together. And the price of such a radiator is much higher. At disassembly, you can buy it for 5-10 thousand rubles.
Device
Automotive oil cooler for automatic transmission consists of the following elements:
- Top tank.
- Core.
- Lower tank.
- Fasteners.
The main purpose of the element is the cooling of the liquid entering it. Typically, the tanks and core are made of brass. As practice shows, this material has excellent thermal conductivity and, accordingly, has a high efficiency.
The core consists of thin plates arranged transversely. Vertical tubes pass through them. They are soldered to the plates and are non-separable. The oil passing through the core diverges into many flows. This ensures rapid cooling of a large volume of liquid. The oil cooler with automatic transmission is connected using pipes. Usually they are made of rubber.
Optional automatic transmission oil cooler: is it worth installing?
All cars that come with automatic transmission are already equipped with a heat exchanger for ATP fluid. But practice shows that such radiators do not always cope with their task. Especially often owners of turbocharged cars - “Subaru”, “Toyota”, etc. are faced with overheating of the box. Therefore, the question arises of installing an automatic transmission oil cooler over the main one.
Getting Started
What do we need for this? In addition to the heat exchanger itself, it is worthwhile to purchase fasteners and oil-resistant reinforced hoses with a length of 1.5 meters.
We also need an oil thermostat. We need it so that in winter the liquid does not cool. The oil in the automatic transmission should work in the mode from 75 to 90 degrees Celsius. Anything below or above these values is invalid. We pay attention to the fact that when installing an additional automatic transmission oil cooler (it will be universal or not, it does not matter), it is worthwhile to include a thermostat in the circuit. It will block the cold flow of oil. Thus, the liquid warms up faster to operating temperatures in the winter, and you will ride a workable warm box.
Consider the features of the installation on the example of the car "Subaru Forester". So, first we need to decide on the installation diagram. Experienced motorists do not recommend installing an additional heat exchanger in the receiving line of the factory cooler. This solution is useless, because at the exit from the factory radiator we will get hot ATP-liquid heated to 95-100 degrees. But how to install it? The most correct option is to install the element in the return line, which is located on the way from the factory radiator to the automatic box.
Having dealt with the installation diagram, we proceed to the dismantling of the body lining. First you need to remove the headlight from the driver's side and the bumper. Next, remove the tube from the expansion tank and remove the mounting of the main radiator. It is mounted on the front panel.
Since we also have an air conditioning radiator nearby, we cannot allow both coolers to be next to each other. To do this, use a 3-mm spacer and stick Teflon plates on the fasteners of the automatic transmission additional radiator. During installation, the element may get skewed. To avoid this, it is necessary to trim the plastic clips of the ties. During installation, the latter must pass through the cells of the air conditioner cooler and a standard heat exchanger. At the exit, the couplers are fixed with a hat. Such fasteners are carried out at four points.
But the installation of the oil cooler for automatic transmission does not end there. Next, you need to remove the radiator tank. It is mounted on two bolts. Then you should unscrew the three screws securing the bracket with fans. So we get free space for tightening the caps from the inside of the radiator. On the right side of the bumper we see two oil lines. We need a return. It is easy to recognize her - she is further from the "stern". When removing the nozzle, be prepared to spray ATP fluid. It is better to plug it with a homemade stopper or substitute a clean container under the hose. Next, connect the oil thermostat. It is not necessary to drill fasteners - just fasten it on two construction ties.
Final work
After the oil cooler automatic transmission has been connected, we check the reliability of all connections. Do not start the car until the oil level in the box has been checked. As another coolant has appeared in the system, the level of ATP fluid may drop. So, add oil to the transmission and start the engine. Assembly of the cladding should be continued, making sure that the system works correctly.
Check the temperature in all four hoses (it is better to use a pyrometer for this). If everything is correct, turn off the engine and assemble the lining in the reverse order.
Prevention
In order for the additional radiator to last as long as possible, you should know the preventive measures. Periodically it is recommended to perform mechanical cleaning of the heat exchanger. Over time, dirt, foliage, midges and poplar fluff accumulate on the surface of the plates. All this affects the heat transfer. Mechanical cleaning can be done without removing the cooler from the car - just say goodbye on the surface of the "Karcher". But note that the radiator fins are quite fragile. If you choose the wrong pressure, you can damage them.
The radiator can clog inside. To prevent this, the filter and oil must be replaced on time. Typically, the resource of ATP-liquid is 60-70 thousand kilometers. If your car has a collapsible pallet, unscrew it and also remove the chips from the magnets. Back cover is installed on a new gasket.
So, we found out what an oil radiator is, how it is arranged and how to install it in a car with our own hands.