The case FOR a auxillary Automatic Transmission Oil Cooler:
As for the need to fit an Automatic Transmission oil cooler. I suggest that you install a temperature gauge into the transmission line before it enters the radiator (standard transmission cooler). Once you get an idea of the temperatures involved (it can rise between 30 - 50 degrees centigrade) with towing you will never again tow without one installed. They are relatively cheap as compared with the cost of a re-built transmission. I suggest that you take little notice of the person on the Holden Service Department and their opinion that the vehicle does not require additional cooling. Ask the Police Departments why they insist upon additional coolers on all of their automatic vehicles. Ask Holden why it fits and external cooler to the Adventra. They probably won't know but it is to allow for greater cooling during 'extreme' off-road driving etc. Towing is considered as 'extreme driving conditions'. Apart from truck prime movers and large agricultural tractors no vehicles are actually designed for towing. Vehicles commonly used for towing caravans etc are always a compromise between cost and capability and often require modification(s) to enable safe and successful towing.
Have a read of the following for some ideas:
Heat is Your Transmissions Greatest Enemy
Overheating is responsible for the majority of automatic transmission failures. Normal temperatures run about the same as the engine coolant temperature which is regulated by the thermostat to around 90 degrees C.
This brings up a very important point. A well maintained cooling system can extend the transmissions life. Part or all of the transmissions oil cooling function, depending on your vehicle, is built into the vehicles radiator. If the vehicle has an external auxiliary transmission cooler, outside of and usually in front of the radiator, it can help keep the transmission oil and engine coolant cooler. You should always install an additional cooler in-line with the standard cooler as the engine relies on temperature generated by the transmission to assist with raising the operating temperatures for optimum operations.
As the temperature of the transmission fluid increases, the life of the fluid deceases very rapidly:
?90 degree C. allows the fluid to be run for up to 80,000 kilometres before servicing is required
?100 degree C. causes the fluid life to be cut in half to 40,000 kilometres
?113 degree C. causes the fluid life to be cut in half again to 20,000 kilometres
?123 degree C. causes the fluid life to be cut in half again to 10,000 kilometres
Based on these temperatures you can see that one overheat condition of the cooling system or the transmission is cause for immediate replacement of the transmission fluid. (Many Police Departments insist that after a high speed chase, obviously involving Police vehicle(s), that the transmission fluid and brake fluid are completely drained and flushed owing to the extreme temperatures generated and potential for severe damage to components).
Towing Increases the Temperature
Light to moderate load towing will try to increase the transmissions temperature but the cooler would control it under most conditions. If the outside temperature is too high, you are towing in mountainous areas or any of the three following are happening your transmission is at risk:
?Towing in overdrive when it is not recommended for your transmission will cause excess heat and probable failure of the overdrive components in the transmission.
?The extra weight of towing puts additional load on the engine and transmission which will increase the operating temperature of both. If the cooler can’t handle this extra heat the transmission fluid life is reduced as stated above.
?Towing a load over the rating of the tow vehicle, besides being unsafe, will also drive temperatures too high.
Add Extra Cooling if Towing
Installation of an auxiliary oil cooler can protect against excess heat causing premature transmission failure. Dropping the fluid temperature by 20 degrees F. will potentially double the life of the fluid. Most external coolers will drop the fluid temperature by 20 to 30 degrees F.
Service it Regularly
Have a thorough read of your Owners Manual. Most (probably all) manufacturers recommend servicing of both vehicle and transmission at more frequent intervals if the vehicle is driven in harsh (dirty/dusty/rural) conditions including towing.
Most repair shops recommend servicing your automatic transmission around 50,000 to 80,000 kilometres for normal driving conditions which exclude towing or extreme hot, cold or dusty conditions.
Prices for a complete filter and fluid replacement normally run around $120 to $180. If you are just getting a fluid flush the price runs in the $80 to $100 range.
Some transmission repair shops do not perform flushes. They believe the best method is regular removal of the oil and filter by removing the pan on the bottom of the transmission (good advice). You should also be aware that some manufacturers, like Honda, have clearly stated not to flush their transmissions in one of their factory bulletins.
As described above the breakdown of the fluid due to heat causes it to not protect the internal moving parts of the transmission. This will greatly shorten the life of your transmission. Overhaul or major repairs run in the area of $1600 to $8000 depending on the extent of internal damage and the type of transmission.
YOUR MONEY - YOUR CAR - YOUR CHOICE.
