Thursday, January 7, 2010

Let’s talk Towing

Towing done right can be painless for you and your vehicle. Let’s start with the basics. With most automatic transmissions you should have an external transmission cooler to keep the transmission... cooler.

Why do I need a transmission Cooler?

A cooler will help the transmission live longer because it will keep it at a lower operating temperature. To understand why, you must understand how an automatic transmission works. Basically, an auto transmission is a hydraulic pump, and it uses rubber seals to contain the pressure of the pump. This is important because when rubber is made, it must be cured for a set time, at a set temperature. When you drive your vehicle your transmission heats up, and in effect continues curing the rubber seals. So in effect, you are curing your rubber seals every time you drive. However, the problem with this is that they aren't being cured correctly and are really just breaking down. At lower temp you cure them more slowly, so it may take 200,000 miles to make them fully cured or as hard as a rock instead of 90,000.

How it All Comes Together

When you tow a trailer or a car, that something resists moving. That resistance to moving causes elevated temperatures in the transmission. If you get the temp high enough you can cure the seals in a few thousand miles, meaning they no longer seal correctly and you have a transmission with low pressure, that will soon stop functioning.

There are a few things you can do to keep you transmission healthy
  1. Install a transmission cooler if you don't already have one. If you have a tow package you will already have one.
  2. When you tow always use light throttle from a stop. You aren't going anywhere in a hurry anyway and this one thing will reduce wear dramatically.
  3. All modern automatics have a lock up torque converter. This feature saves fuel and keeps the transmission temp down. Most of the heat generated in the transmission is from the torque converter. When you climb a long hill you step on the gas to maintain speed, as you do this you command the torque converter to come out of lock up so you have more power. When this happens the temp goes up rapidly. On a small hill it's no big deal but on a long climb you can overtemp the transmission and cause fluid to run out of the dipstick.GM has had a locking dipstick on their transmissions for many years. This is because when people would tow, they would be in a hurry to get up the hill and they would push the temp up until it ran out the dipstick. From there it ran onto the exhaust manifold and caught on fire. Keep the transmission converter in lock up .You can tell when a converter comes out lock up because the engine will gain 300 rpm without shifting.
  4. When I tow I take the vehicle out of overdrive. This helps it stay in lock up and reduces stress on the transmission. The biggest thing to take away from this article is speed kills. Don’t be the first up the hill or off the line and you will be ok.

By: Ray Seiler: For more information on Ray's Qualifications and Experience view the About the Author page.

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  1. Such interesting post you have here for us. Direct and well detailed content, definitelyy interesting. Thanks a lot for sharing the tips.

  2. "Install a transmission cooler if you don't already have one. If you have a tow package you will already have one."

    This is my Favorite, I can't tell you how many people tow a boat and have no idea they should have one. Amazing...

    Well Written article, very informative!