Remove a belt by inserting a 3/8 drive ratchet into the 3/8 inch sqaure hole in the automatic tensioner and rotating it counter clockwise (unless you have a 3.0.)
Tension is set by the spring force in the tensioner. Sometimes the pulley itself needs replacement if it free spins; meaning its lost its grease and the bearings are wearing out fast or it's seizing and the belt is eating it up. Then sometimes the whole tensioner needs replacement if a new belt is installed and the tension produced on it by the tensioner exceeds the amount of belt deflection specified by your manual. Deflection is a measure of how taught the belt is. So that's what you use to tell if a belt is too loose, or before automatic tensioners, too tight.

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08 4.0 Sport 4x4
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