Changing the thermostat on a 4.7L Dodge:
Things You'll Need:
* Catch pan
* Ratchet and socket set
* Floor jack (if necessary)
* 2 jack stands (if necessary)
* Rib joint pliers
* Ratchet extension
* Plastic scraper (if necessary)
* New O-ring seal or gasket
* Distilled water
* New antifreeze
Removing the Thermostat
Place a catch pan under the radiator valve. The pan should be large enough to remove at least 2 gallons of coolant from the radiator, if you have a 3.7L or 4.7L engine model or 1 gallon if you have the 5.7L or 5.9L engine models.
Open the radiator drain valve, loosen the radiator cap and wait until you have removed enough coolant. Then close the radiator valve.
Disconnect the ground, black battery cable using a wrench.
Detach the alternator mounting bracket to intake manifold, if you have a 5.7L or 5.9L engine model. Use a wrench or ratchet and socket. Following the instructions on your car owner's or service manual for your particular model, remove the accessory drive belt, the two alternator mounting bolts, and indicator lamp wiring harness [on 4WD models]. This will allow you to move the alternator aside.
Raise the front of your Ram with a floor jack and support it on two jack stands, if you have a 3.7L or 4.7L engine model.
Remove the splash shield from under the radiator using a ratchet and socket, on the 3.7L or 4.7L engine model.
Disconnect the lower radiator hose at the thermostat housing using a pair of rib joint pliers to remove the clamp on the 3.7L or 4.7L engine model. On 5.7L or 5.9L engine models, disconnect the upper radiator hose instead, following these same instructions.
Unscrew the two thermostat-housing mounting bolts using a ratchet, ratchet extension and socket.
Remove the thermostat housing. If you have a 5.7L or 5.9L engine model, remove the gasket and traces of gasket from both mating surfaces using a plastic scraper to avoid damage to the mounting surface.
Installing the Thermostat
Make sure the mounting surfaces are completely clean.
Position the new thermostat along with a new O-ring seal in its mounting place on the engine and make sure the spring points to the engine. If you have a 5.7L or 5.9L engine model, install the thermostat gasket now.
Set the thermostat housing in its mounting position and start the two mounting bolts by hand. Then tighten the bolts using the ratchet, ratchet extension and socket. On 5.7L or 5.9L engine models, make sure the "Front" mark on the housing points toward the front of your Ram model.
Attach the lower or upper radiator hose to the thermostat housing, depending on your particular model, using the ratchet, ratchet extension and socket. Then use the rib joint pliers to secure the hose with the clamp.
Install the splash shield under the radiator using the ratchet and socket, if you have the 3.7L or 4.7L engine model. Then lower the vehicle.
Attach the alternator, indicator lamp wiring harness [4WD], accessory belt and alternator mounting bracket to the intake manifold, if you have the 5.7L or 5.9L engine model. Use a wrench or ratchet and socket. Follow the instructions on your car owner's or service manual for your particular vehicle.
Connect the ground (black) battery cable using the wrench.
Refill the system with a 50/50 mixture of distilled water and antifreeze.
Start the engine and watch for leaks at the radiator hose connected to the thermostat housing.