300d AUTOMATIC TRANSMISSION UPGRADE

When towing, you need to install a better tranny oil cooler. That is all you can do... it will have a dedicated radiator for the oil cooler and will also increase the capacity of oil... therefore, it keeps your tranny cooler in the time of hard towing. Otherwise, the tranny will frie up.

You could also upgrade your cooling system by adding a Kenlowe type fan. Remember that you don't want cool oil; you want oil the correct temp for the job the car is doing. When towing you need more cooling to achieve this, but when you are just driving you want your transmission oil at the correct operating temp.