7. Transmission UpgradesWith more power on tap, you will need to protect your transmission from the stress of pulling a trailer. High temperatures, combined with heavy loads, are the number one cause of transmission failures, and nothing ruins a trip quicker than metal shavings in the transmission pan. Upgrading to a multi-disc torque converter will reduce slippage between the engine and transmission, and help keep your automatic operating in the safe zone (less than 200 degrees Fahrenheit). A heavy-duty rebuild will often include a torque converter upgrade, along with stronger gears and shafts, better seals, high-performance pumps, new bearings, Kevlar bands, and a larger capacity oil pan with fins to aid cooling.
8. Transmission Temperature Gauge and Auxiliary CoolerJust like EGT, the operating temperature of your transmission should always be on your mind while towing. Any more than 200 degrees Fahrenheit for extended periods of time can make your slushbox vulnerable to failure, especially when you are pulling a heavy load. HD trucks may include a factory transmission temperature gauge, but if you don't have a way to monitor your transmission, then you need one. Some companies sell in-line transmission oil filters (for added safety) that include a temperature gauge. If your readings are constantly pushing the limits, it's time to start shopping for auxiliary oil cooler. These units will lower the operating temperature of your automatic in all conditions, which is great, because a 20 degree reduction is said to double the life of a transmission.
9. Brake UpgradesStock four-wheel disc brakes are great but can quickly be overwhelmed when asked to slow more than 10 tons of truck and trailer. Aftermarket brakes offer advantages such as larger discs, six-piston calipers that are better at clamping, and slotted and drilled disc rotors designed to funnel warmth into the ventilation vanes and out of the brakes. Upgrade brake pads are built with high-friction compounds for quick deceleration and extended fade resistance. When ordering, make sure the new brake kit is designed to work with your truck's antilock programming.
10. Exhaust BrakeYou've probably heard semi-trucks engaging their exhaust brakes on downgrades, and you can use the same technology. Gasoline engines can slow a truck after a downshift because the engine is trying to pull air through a closed throttle. Since diesel powerplants have unrestricted access to air inside the intake, downshifts will not do much to slow your truck. An exhaust brake is a valve installed in the exhaust system that will restrict the exit of gases and provide resistance to revolutions in the drivetrain. This provides a way to slow your truck by as much as 50 percent without constantly using the wheel brakes, which can overheat and fail.
11. Trailer Brake ControllerA Trailer Brake Controller (TBC) is a great way to increase your ability to safely tow a heavy load. It works by synchronizing the truck brakes and the trailer brakes, and allows the driver to adjust the output and gain to compensate for the load being carried. Trailer brake controllers are a factory option for some heavy-duty trucks and are available from many aftermarket companies. This is another one of the "if you don't have it, you need it" towing upgrades.
12. Aluminum Differential CoverNot only does it look cool, but an aluminum differential cover can keep your gears from turning into an axle grenade. Towing puts tremendous strain on the entire drivetrain, but a stock rear differential can have trouble dispersing the heat that is created. Aftermarket covers have more gear oil capacity and include heat-sink fins to help diffuse heat created by the gears' movement inside the differential.