Be kind to your transmission for a long and happy life


    By Greg Illes

    Most of us check our transmission fluid now and then (don’t we?). Some of us even have it changed every once in awhile. But aside from that, what else is there to do with a typical automatic transmission other than drive it, and hope it keeps on working?

    There are actually some very proactive things that can be done to give your transmission the best possible chance for a long and happy life.

    Never forget that your transmission is not only a key link in your drive train, but one of the highest stressed as well. A typical motorhome, or trailer-hauling vehicle, works its transmission many times harder than any comparable street vehicle. And the single biggest enemy of your transmission is loss of lubrication. This can happen from something as simple as a leak (loss of lubricant) to something more insidious — the loss of the lubricity (capacity for reducing friction) of the oil in your transmission.

    Fact is, transmission oils simply wear out. They work so hard that the long-chain molecules in the oil break up into shorter chains, with less lubricity. This happens largely due to only two factors: load and heat. The heavier the load and the higher the heat, the shorter the life of the transmission oil (and the transmission).

    What can you do? It’s fairly simple and comes in two stages:

    Give your transmission the best possible lubricant money can buy. Cash spent on the excellent synthetic oils available will be more than paid back by extended transmission reliability and life span. Monitor the oil and change it at regular intervals, or when it shows any sign of wear (discoloration or burned smell). Make sure you have a good transmission cooling system in place. This can be as little as a standard cooler in front of the engine radiator, or you can buy some more “temperature insurance” and install an aluminum oversize transmission sump. Both of these will drop transmission temperatures, increase fluid life and add to reliability and transmission life.

    Lastly, it’s a good idea to monitor your transmission temperature, especially on hot days and steep climbs when it works the hardest. Many coaches and trucks have these gauges stock, or you can add one at a modest cost. Knowing when your transmission has undergone a long, hot spell can clue you in to managing your driving patterns, and changing that precious transmission fluid right after it’s been “cooked.”

    photo: Hatsukari715 Wikipedia/public domain

    Greg Illes is a retired systems engineer who loves thinking up RV upgrades and modifications. When he’s not working on his motorhome, he’s traveling in it. You can follow his blog at

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