Transmission Takeaway

Are you finding your options becoming more and more limited when one of your light-duty vehicles has transmission troubles? You're not alone. As fuel-efficient--and technologically-complex--six-speed transmissions saturate the light-duty market, fleet maintenance managers may have to re-adjust their repair philosophies.

According to Wayne Colonna, president of Miami, FL-based Automatic Transmission Service Group (ATSG), technical information is quickly becoming a scarce commodity. "The manufacturers are not as forthcoming with the information as they used to be," he explains. "First of all, there are more transmissions coming out now than ever before--we have such a wide variety. And the technology involved has increased dramatically."


Colonna has been president of ATSG, an employee-owned technical support service, since only 2001, but in that short time he has seen epic changes in this part of the industry.

"What we're seeing is that the manufacturers are trying to get it to a place where they just want the transmission changed," he says. "They can't find the right--or enough--technical guys to actually support repairs at their own dealerships, so it's much easier for them to just pull the transmission out, put another one in, change the computer, whatever they've got to do."

As a result, very little information is provided by the OEMS about the internal components of the transmission. It is becoming, essentially, a mystery box that technicians open at their own peril. And when they do open it, they find more and more that they can no longer simply replace the faulty component.

Colonna points out the valve body as a particular trouble spot. "The valve body is the component inside the transmission that shifts the transmission through the gears, and it's usually via solenoids that the computer controls," he explains. "The valve body has the shift solenoids, the pressure control solenoids, but the (OEMs) don't really give you a breakdown. They prefer just selling you a whole valve body with the solenoids instead of doing individual component sales.

"More and more of these transmissions are actually putting the computer inside the transmission, and it's usually mounted on the valve body," he continues. "So now, if you need a solenoid, you pretty much have to buy the computer, the valve body assembly and the solenoid. They don't sell it individually.

"So again, we're getting into subcomponent parts replacement instead of being able to replace individual components," he says.


Colonna has a beef with the "Right to Repair" movement, but not because he thinks it's a bad idea; he just thinks it's distraction from the real issue. Technicians already have a right to repair, he claims, but the OEMs have defined "repairing" as "replacing entire systems."

"It's just a smokescreen, as far as I'm concerned," he says. "For me, what's really happening is, they're taking away the right to rebuild. Sure, you can repair it; change the transmission and you've repaired the car. Sure, you can repair the transmission; change the whole clutch drum assembly for $800--we don't sell the individual components, so buy the whole drum assembly, or the whole pump, or the whole valve body.

"So, they're taking away our right to rebuild, and the prices to try to make those repairs are challenging, especially when the manufacturers provide remanufactured transmissions at a much lower price than you could repair them or rebuild them for, because of the way they price up these subcomponent parts," he says. "So we rely very heavily on aftermarket companies coming out with different repairs and parts to try to get around this problem, as well as any used parts that we call ‘good experienced parts.'"


If you can get past the problem of being forced to replace entire subcomponents and transmissions instead of actually repairing them, Colonna says that the real challenge for a transmission technician is knowing the ins and outs of transmission fluid.

"The big problem that maintenance people face--and this is a huge problem--is that each car manufacturer is requiring very specific transmission fluid, and very, very expensive transmission fluid," he explains. "Now, if you have a fleet and you're dealing with all of the same type of transmission, well then that's not so bad; you can get yourself a big, 55-gallon drum and you're good to go, because it's the same fluid for all your vehicles. But if you've got a variety of different transmissions, you've got yourself a problem, because if you do not put the right transmission fluid in, you will have slide shift, bumps, chatters and premature failure of the transmission. It's that critical.

"It's a very high-end synthetic fluid, and the computer controls clutch apply and converter clutch apply in various different ways, where there's a tremendous amount of slip on the clutches," he says. "If the fluid is not right sometimes you can feel the frictions clapping on and off, and it feels like a chatter. The clutch will overheat and burn out, you'll feel it."


So, you've got the proper fluid or fluids for the transmissions in your fleet, and your technicians know which fluid goes with which vehicle. But there's still a problem--actually two problems: no dipstick, and, more often than not, no filler tube.

According to Colonna, this is all in a day's work for a transmission technician.

"You have a standpipe, of sorts, in the bottom pan, and there are various combinations; there's one style where it could be a drain plug as well as a check plug," he explains. "In other words, if you looked at the boot pan you'd see a fairly large nut, and in the center of that nut is another nut, with an allen head. If you took the allen head out, you'd look up inside and there's a tall standpipe, and the fluid level is determined by whether or not the oil comes out over the top of that standpipe. If you took the bigger nut off, then it becomes a big hole in the pan and it becomes a drain plug. And sometimes in order to fill it, you actually have to force oil, or push it, up that little standpipe, until the oil comes out over the top of the standpipe."

If you think that sounds complicated, Colonna also describes a layout where there is a "remote fill location" on the side on the transmission, with an access port that would allow the technician to add fluid until it comes out over the top of the standpipe in the pan.

And there's more: "Some guys maybe will pull a vehicle speed sensor out of the case to gain access through the hole to fill in that way," he says.


With so many different fluids, and so many different methods of checking and filling fluid, a transmission technician needs to be familiar with every type of transmission in the fleet. And, he or she needs to keep track of changes, both big and small, that come with every new model year changeover.

"So it is a can of worms," Colonna says, even though he admits that many transmission shops have reaped the benefits of that can. After all, if a do-it-yourselfer or even a rookie fleet technician can't find the fill tube--perhaps doesn't even realize that there no longer is a fill tube--he or she is going to have to bring the vehicle into a transmission shop.

"But it is a pain in the ass, actually, depending on the carmaker," Colonna says. "Mercedes and Chrysler actually sell a tool to check the transmission fluid level. There is a fill pipe, however on the top of the fill pipe is an actual breather cap. You remove the breather cap, and with this tool--it's really a dipstick, but it's a universal one--you'd be able to check the fluid level of the transmission. But Ford, GM, they have a variety of different ways of checking the fluid level."


In the training sessions that he gives around the country, Colonna meets many technicians who can rebuild a transmission blindfolded but are still stumped by electrical problems.

"They could take a transmission out, repair it and put it back in, and so when there would still be a problem it would go to driveability shops to try to find out if there were electrical issues," he says. "The driveability shop could work it down so far, but then they'd be stumped because they really don't know anything about transmissions."

As a result, driveability issues sometimes end up lost in maintenance limbo: Is it an engine problem or a transmission problem? How can a technician tell?

"It's really a very large subject," Colonna says. "Just to give you an idea, you could have a mass air-flow sensor that's malfunctioning, and the computer's not producing a code for it to indicate a problem with the mass air flow sensor. Not only could it have an effect on the engine's operation, but it also has an effect on transmission operation. It elevates line pressure and now you have extremely hard shifts, later shift points, and the transmission feels like it's the problem, but it's not."

And that's a simple example, according to Colonna. He goes on to cite a situation in which a transmission wouldn't budge when the car's headlights were turned on (Cause: a bad ground in the trunk wiring), and one in which a BWM's transmission refused to shift after the owner put on a temporary spare (Cause: The spare had deeper tread than the other three tires, fooling the transmission computer into determining that the car was in a constant turn, and triggering the "curve recognition" function that inhibits shifting while cornering). How is a transmission technician supposed to figure that out?


The problems only get more intense with the increased computing power required by new six-speed transmissions. Many new units, for example, monitor the length of time it takes to shift from one gear to the next, and can spring into action if there's a lag.

"If it starts to become too long, the computer adjusts the pressure in the transmission to try to bring that shift down to where it doesn't take so long," Colonna explains. "They call that ‘shift adapts.' It adapts to the shift, it adapts to the driving conditions, to the driver. If the transmission starts to slip, it'll elevate line pressure to get rid of that slip. As a result, the transmission starts to feel a little bit bumpy on the shift, and in time the transmission may fail."

But, unless your shop has the OEM tool to precisely reset those shift adapts, the transmission can continue to slip or have extremely hard shifts. And even if you have that tool and are able to reset the shift adapts properly, a problem with an engine load device such as the crank sensor or the cam sensor can affect the settings for the shift adapts, potentially bringing that transmission right back into the shop.

"Is this subject large? Yes it is," says Colonna. "I speak for six or seven hours on this subject at seminars. It's really gotten to a whole ‘nother level."


Where does that leave transmission technicians?

According to Tim Schmidbauer, owner of TNS Transmissions in Hales Corners, WI, he and his two technicians rely on their familiarity with traditional transmission technology to guide them, but when that isn't enough they turn to Colonna's group and to the Automatic Transmission Rebuilders Association (ATRA). "They have a hotline you can call and have a technician work with you on electrical issues or hydraulic issues, or whatever it might be," he says.

"Sometimes you want to tear your hair out," Schmidbauer says of diagnosing complicated transmission problems. "Still, in the end we always figure it out."

On a final note, Schmidbauer, whose shop does transmission work for the City of Milwaukee, WI, fleet, often has to deal with a decidedly low-tech problem: unskilled fleet drivers.

"It's not their vehicle, so they may have a problem, and instead of addressing it right away they let it completely fail," he says. "With automatic transmissions, you could get slips or flutters between shifts, fluid leaking; if you don't catch it you could burn the transmission up.

"It would be nice if they could catch the problem before it becomes a complete overhaul," he says, recommending that drivers in doubt just pull over and call the tow truck.

For technical assistance, or a schedule of upcoming training opportunities, go to and