What is the pulley called that is to tighten the belt on a 1998 dodge ram 1500 4wd truck?

most tensioners are spring loaded. you put a socket and a Johnson bar (as we used to call it) on the pulley and turn the pulley away from the belt so you can remove the belt.
As for the squeak, try some belt lube
To re-tighten the tensioner, you may have to loosen the mounting bolts and put some type of pry bar between the mounting bolt assembly the put downward pressure on it and tighten the bolts.

it the pulley has ridges an/or lips the ridge(s) side of the belt goes around it. if the pulley is smoth then the back side of the belt goes around it. You shouldnt need a diagram.

Moist adjust via the alternator mount, Use a pry bar to pull the belt tight and tighten both bolts to keep it there.

The tensioner is a spring loaded unit that is supposed to provide the proper tension on the belt with out adjustments. Ususally if a tensioner goes bad it is not providing presure on the serpentine belt (loose belt, squeel, or squeek) or it has a bad bearing in the tensioner pulley (noisy, siezed). The tensioners are sold as an assembly in either case. If the tensioner went bad it is a good idea to replace the serpentine belt at the same time.

Please tighten the grip for the belt to enable tighter stay in-line.

Sorry.

It may be the water pump that is making the noise if the noise is constant.

YOU HAVE WHATS CALLED A TENSIONER PULLEY IN FRONT OF ENGINE , ONE OF TWO PULLEYS THAT ARE SLICK (NO GROOVES). THE TENSIONER PULLEY IS WHAT YOUR AFTER. IT WILL BE ATTACHED TO A SLOTTED BRACKET WITH A BOLT HEAD DIRECTLY BEHIND IT.(LOOKING AT ENGINE FROM FRONT OF VEHICLE ITS USUALLY ON YOUR FAR RIGHT!) FIRST UNLOOSEN BOLT ON FRONT OF PULLEY ABOUT FIVE TURNS , THEN MOVE TO BOLT ON TOP BEHIND PULLEY , AND START UNLOOSENING IT TILL PROPER TENSION IS RELEASED TO SLIDE BELT OVER ALL PULLEYS(USE BELT DIAGRAM UNDER HOOD FOR PROPER INSTALLATION. ONCE BELT IS ON REVERSE STEPS 1 AND 2. TIGHTEN TOP BOLT BEHIND TENSION PULLEY TILL BELT HAS ABOUT A QUARTER INCH PLAY IN IT UP AND DOWN (DON'T OVER TIGHTEN).THEN TIGHTEN FRONT PULLEY BOLT TILL VERY SNUG.YOUR DONE! BELT MAY NEED RE-TIGHTENED AFTER DRIVING A FEW DAYS , BUT YOUR AN EXPERT NOW AND THAT WON'T BE A PROBLEM. HOPE THIS HELPED!

To change the serpentine belt is very easy, If you look carefully, you will find a pulley between your alternator and air conditioning pump, this is called the tensioner, In other words the pulley that pushes down the belt between the alternator and a/c pump. Place a 1/2 drive wrench to pull the tensioner up. This will loosen the belt for replacement. Hope this was helpful Good Luck =)

easier on lift if not ramps on ground chalk wheel use stands once all belts are off remove center bolt on bottom crank pulley install crank pulley remover you may have to remove outer part of split pulley thread three puller bolts into bal there should be holes for this snug all three tight install adapter into center where main bolt came out thread tool against adapter as you tighten in the bal pulls out once out replace timing case seal at bottom of cover lightly apply grease or lithium on inside of seal put new bal alighn on keyway install reinstall tool slowly with air ratchet or impact gun reinstall slowly the grease on seal will stop seal from dry start up once bal all the way in install center bolt outer pulley if taken off belts etc