Performance automatic transmission failure may not spring up from thin air. Rather, this failure may be caused by our own making due to certain mistakes. You may have purchased a performance car or truck with one of the best transmissions or even carried out a rebuild.
However, these mistakes could impact on the lifespan of the transmission. Accordingly, we’ve outlined some mistakes to avoid while handling your performance automatic transmission. You’ll find these tips helpful whether you’re a racer or performance enthusiast.
Mistakes to Avoid When Handling Performance Automatic Transmission
Here is a list of things to avoid when dealing with your performance automatic transmission.
1. Using the Wrong Dipstick
It’s entirely possible to use a transmission dipstick that doesn’t take the right oil measurement. When that happens, you’ll be misled to believe that you have enough oil, when in actuality you don’t. Besides, the transmission pan’s width and length in comparison with its shallow depth show that even a quarter of an inch off dipstick reading can be bad. It could mean running your transmission on low oil, which has negative effects.
For starters, you could damage the transmission if you’re using it in a performance scenario with high demand for oil. On the other hand, you can ensure your dipstick gets the right measurement each time by examining the object yourself. You need to fit in the dipstick in place, drop the transmission pan, and then ensure that the full mark is even with the transmission case’s bottom edge.
And if you notice that the original mark on the dipstick is low, proceed to create a new mark on the dipstick. The mark doesn’t have to be something major, but obvious enough for you to spot it out anytime. Now that you have gotten a better-marked dipstick, you’ll get the accurate measurement of the transmission fluid.
2. Lack of a Transmission Cooler
The regular vehicles come with a transmission cooler located in the radiator. While this cooler may be enough to dissipate heat in regular cars, if your vehicle is built for performance driving, then it needs an extra cooler. The same goes if your engine has been designed to handle high performance or features a higher stall torque converter.
The reason is, the original cooler may not offer adequate cooling to maintain the temperature in a viable range. And heat can lead to major issues in the car, which brings the need for adequate cooling.
To that effect, get an external cooler with a fan which will ensure there is a free flow of air through the cooler. Also, the ideal temperature range of operation for a good number of automatic transmissions is around 165 to 220 degrees.
3. Wrong Line Pressure
The Engine Control Module (ECM) is used by most new vehicles to regulate the transmission’s line pressure and the latter makes such adjustments easy. Tuners may also jack the line pressure up all in a bid to get better shifts, however, there is a need to exercise care. This is because a line pressure that is overly high can lead to hard shifts thereby ruining internal components.
There’s the GM 4L60E, for instance, whose input drum and the input shaft is aluminum and steel respectively. Consequently, the slam shifts of the transmission could crack the drum right where the two parts spline together.
4. Irregular Servicing of the Transmission
It is important to change the transmission fluid and the filter each year. The same applies even if the vehicle is driven irregularly or has been left idle for a long time. For instance, if you tend to use the vehicle on the weekends, the fluid needs to be changed at about every 12,000 miles. There are several reasons why regular change is important.
First off, the engine oil may break down after a while and therefore, not serve the purposes it was intended. These purposes include lubricating the transmission to reduce wear and serving as a hydraulic medium that enables the transmission to function.
The transmission fluid also absorbs heat generated within the transmission and then radiates the heat through the case of the cooler. It is worth noting that the transmission fluid will still serve its purpose as hydraulic fluid over time, but it may not lubricate or dissipate heat properly due to the breakdown of the fluid.
That aside, the filter has to be changed since mechanical parts wear out and create debris that contaminates the fluid. And changing the filter will allow more of this debris to be trapped without entering the oil. A change in the filter is even better than only a transmission flush. This is because the accumulated debris can be removed, thereby unclogging the filter to enable the free fluid flow.
5. Wrong Installation of the Transmission
It’s possible to have wrongly installed the transmission and even the torque converter. Nonetheless, a better approach to install the torque converter is to pour in some ATF into it enhance flow at the first start-up. A quart of fluid should be poured into the converter even before you install it in the transmission. After installing the converter, check if the dipstick reading is correct.
Alternatively, it is important to install the torque converter into the transmission fully before the transmission is placed on the engine block. And do not use force to tighten the transmission to the block by tightening the bolts of the bell housing. You’ll easily know that the torque converter has not been well inserted into the transmission if it won’t fit in place.
6. Bad Throttle Valve Adjustment
Transmissions like the 700R4 fail mostly due to the improper adjustment of the detent cable. The 700R4 uses a cable and fulcrum setup when stroking the throttle valve (TV) in a bid to adjust the line pressure. An increase in the throttle leads to a rise in the line pressure. Contrastingly, the 4L60E uses an electronic pressure control solenoid (EPC) to control the line pressure.
As the throttle increases, this valve causes line pressure to rise for more clutch holding power. Adjusting the valve the right way involves removing the pan and adjusting the cable. This adjustment will ensure that the gas pedal when it is pressed to the floor, the TV valve is completely stroked in.
7. Full Throttle Lockup
The tuner or dyno tester may hit the lockup at full throttle. This setting is not needful if you have more engine power, as well, as a lockup converter. You should not also have the expectation that one lockup clutch can easily handle more horsepower at full throttle.
There are also two options you can select from, and that is choosing between a triple-disc converter or hire a tuner to program the ECM to ensure that there is no full-throttle torque converter lockup.
The Bottom Line
Following the tips outlined above, you can avoid performance automatic transmission failure especially those that stem from mistakes. You’ll know just the right time to change the oil, replace the filter, adjust the line pressure amongst other things. Therefore, if you’ve spent heavily on a high-performance transmission, it can stand the test of time.