Transmission Trends

How transmission technology has changed the work practices of the fleet technician


There is a little bit more of an investment going into it when you purchase it new--in other words, an automated transmission versus a manual in a less than 26,000 GVW truck might cost the average person off the street a $4,000 to $5,000 upcharge--but over the period of time that he owns that vehicle, he sees that back in reduced maintenance costs.

FM: How have automated and automatic transmissions affected your fleet cost-per-mile?

MH: Obviously we have fewer transmissions that we have to pull and replace due to, shall we say, a lack of driver experience. When you don't have to do that, then you don't have to have the vehicle down for such a length of time, and it allows you to focus on other core competencies.

FM: How have the new transmissions affected your maintenance operations?

MH: Depends on how you use the term "transmission maintenance." You don't have people overhauling transmissions, as I described, and though you still have mechanical issues now and then, because they are totally electronic, you'll always have those challenging electronic issues.

Today, for example, when the engines and transmission talk to each other, it's not uncommon to start getting fault codes where perhaps the engine and transmission have gone out of sync. You have various inputs that tell the transmission when to shift, and you may have to replace sensors. So for transmission repair--and I'm not sure if the term "repair" is a very good one--from a diagnostic standpoint, it's actually gotten more complicated.

With a manual transmission, you would put some gauges on there; if it's a fully automatic with hydraulics, certain pressures will tell you if there's something wrong with that particular gear. But today you've got to hook up electronics--typically a shop diagnostic computer--to that thing, and it tells you what the problems are. A lot of the time, they are things that can be fixed externally, so you don't have to go in the transmission. So, it's a little more technical.

FM: How do you make sure your technicians are properly trained on transmission diagnosis and maintenance?

MH: We work very closely with our key suppliers, and they help get hands-on training to us as well as web-based training.

We also have a proprietary system that we have for our diagnostics. And this is for engine, transmission, etc., we've got everything on one common platform. We work with Nexiq Technologies, which has been one of our partners for at least ten years. They take the various suppliers' software and they do their programming, so now we have everything on one platform, so we have one tool to troubleshoot and diagnose literally anything that we have running in our facilities, whether it's a transmission or an ABS system or an engine.

FM: Have you tried different brands of transmission and transmission fluid? What brands do you use now, and why?

MH: Fully automatic: typically it's going to be Allison; automated: Eaton, or Fuller.

From a transmission fluid standpoint, because they are two different types of transmission, the fluids are different. Actually, they each develop their own spec' that the various suppliers have to meet. We have a major supplier that typically handles all our lubrication products, which is Chevron. So, for example, if they want to market and develop their own transmission fluid for one of these transmissions, they have to work with these two suppliers to pass a series of tests so that they can be approved on their list.

FM: How does the use of automatic and autoshift transmissions play into the company's overall operations philosophy?

MH: Being in the type of business that we're in, it's typically customer-driven. I've already told you that everything under 26,000 lb. GVW is all automated/automatic in our fleet; then again, in the medium-duty straight trucks from 26,001 to 33,000 lbs. GVW, which would be up to a Class-7, we probably have about 40 percent automated/automatic and 60 percent manual. But since they have CDL drivers' licenses, you still have the more experienced drivers, who tend to like a manual transmission.

Now in the tractor fleet, if you asked me about automated transmissions eight years ago, I would have had to search high and low, out of our 65,000 or so vehicles, to find a handful of them. In the last five years we have seen a pretty drastic increase in the demand for the automated transmissions--and it has been primarily automated in the Class-8 trucks, versus automatic. We're up to about five percent of our tractor fleet right now that's automated.

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