5 Myth:
The best material and only type to consider for performance torque converter clutches is always Kevlar.
Reality:
Often the application of the torque converter and the power output of the vehicle, as well as the type of transmission fluid used, will cause a different type of clutch material (other than Kevlar) to be the best choice. Many times clutch materials for lockup-style automatic transmission torque converters will consist of composite media that uses a certain percentage of paper or other elements such as carbon. This ensures the clutch system in the torque converter provides the optimum coefficient of friction to maintain torque-holding ability.
6 Myth:
Diesel trucks produce too much torque for automatic transmissions to handle reliably.
Reality:
Modern automatic transmissions have evolved significantly on late-model diesels and have the capability to handle vast amounts of torque now. Some manufacturers are now offering certain model vehicles exclusively with automatic transmissions. Upgraded transmissions for diesel pickups can now be built to run neck and neck with most manual transmissions, as the manual trans will still have the limitation of the clutch where slippage becomes a factor.
7 Myth:
Band adjustments are required when servicing any light-duty truck transmission.
Reality:
Some diesel owners find themselves getting taken to the cleaner when bringing their truck to a shop for transmission service. Late-model truck owners should be aware that their transmission might not need some services, such as band adjustments. While earlier-model transmissions still made use of the standard bands wrapped around each gear section, late models use a different gear configuration and will not need the band adjustment procedure performed when servicing (i.e. an owner of an '07 Dodge Cummins should be skeptical of a shop that states a band adjustment will be performed on his 68RFE automatic transmission).
8 Myth:
Hard shifting is always best or always required to handle upgraded power on a performance-built transmission.
Reality:
While more positive shifting is commonly used on earlier-model truck transmissions, late-model transmissions use different technology, including progressive line rise. This means during the initial shifting of gears, the hydraulic pressure being applied to the clutch pack in the transmission is lower and is then ramped up increasingly as the torque load amplifies. Also, later-model trucks incorporate a larger number of gears and closer gear ratios that make for a less severe rpm jump during the shift.
9 Myth:
Transmission replacement is a nightmare because it is not known whether the replacement unit will shift and function properly once it is installed in the truck, and it must be installed in the truck to test its operation.
Reality:
Higher-end transmission suppliers and manufacturers use equipment such as transmission dynamometers and valvebody dynamometers to simulate the routines they would perform in the actual truck. These dynamometers run the unit through each shift and test hydraulic pressures multiple times at varied engine loads and give computer feedback to ensure proper operation and performance.
10 Myth:
Transmissions built for racing and sled pulling applications should have no bearing on one's desire to purchase a heavy-duty transmission for trailer pulling and/or work applications.
Reality:
Companies that have experience with building transmissions to stand up to the punishment of racing and sled pulling have an advantage when it comes to producing the best trailer towing transmission. Since the same model transmissions are typically used in both scenarios, the tougher components designed for competition can be used in a transmission built for towing and provide ultimate longevity and performance for everything from daily driving to work situations.