2002 gmc envoy_slt
Here's a thought, ABS helps the tires to maintain traction, but does (generally) extend stopping distances. So ABS could cause you to "slide" into something if it extended the distance too far.wait... what? ABS making you slide into something?? ABS makes sure your wheels don't lose traction with the pavement... Downshifting, while it doesn't hurt anything, doesn't have any way to know or control whether or not the wheels have traction...
The heat goes into the transmission fluid, which is transfered to the coolant. A simple mod would be an additional external transmission oil cooler (with a fan...ideally thermostatically controlled with a manual bypass for off-road applications). By increasing the ability to cool the fluid before it gets to the radiator, you can substantially increase the ability to use the "engine brake" method to slow down. This also reduces the work the cooling system has to do, since at slow vehicle (especially rock-crawling) speeds the airflow over the radiator is due mostly to the fan....A question for deeper thought. If you were slowing down using your brakes they'd get hot. Where does the heat go when you're using your tranny for braking, and what simple mod could you add to increase your ability to slow down on mountain hills?
The engine braking is actually using the drivetrain as a drag on the engine. Therefore, the trans fluid is being heated up. That heated fluid needs to be cooled.(Deep thoughts ahead) The heat that would be dispersed by the brakes is diverted (by downshifting) to the engine and ultimately the radiator to the surrounding air. A more efficient engine fan or radiator would help disperse it. The trans does heat up some, but is not the main heat sink for the energy. It would fry in no time if it was since it is not designed to convert heat into energy (or back).