How to Tighten a 1995 Nissan Altima Belt

The 1995 Nissan Altima uses two drive belts to power the engine accessories. The top drive belt powers the alternator, power steering pump and water pump. The lower drive belt powers the air-conditioning compressor. Both belts are driven by the crank shaft pulley, which is the large pulley that is centrally located. An idler pulley for each belt provides tension to the belts, and each idler pulley has an adjusting bolt used to adjust the tension.
Difficulty: Moderately Easy
Instructions
Things You'll Need
Socket set
Straight edge object
Ruler
Upper Belt
1

Locate the span of the top belt between the alternator and the idler pulley. This is the measuring point for the upper belt. Place the straight edge along the top of this span, and use the ruler to press down on the belt in the middle of the span. Observe how much the belt deflects from the straight edge. If it deflects 8 mm (.31 inch) or more, the belt is loose and needs to be tightened.
2

Locate the adjusting bolt slightly above the idler pulley. Use a socket to rotate the bolt clockwise to tighten the belt. Make small adjustments.
3

Recheck the belt tension using the ruler. Once the deflection falls within 6 to 7 mm (.24 to .28 inches), the belt is properly adjusted.
Lower Belt
1

Position yourself underneath the car. Locate the span of belt between the crankshaft pulley and the idler pulley. This is the deflection measurement point for the lower belt.
2

Place the straight edge along this span and measure the deflection like you did in step 1, section 1. If the deflection of the lower belt is 10 mm (.39 inch) or more, you need to tighten the belt.
3

Locate the adjusting bolt directly below the idler pulley. Turn the bolt clockwise to tighten the pulley. Continue checking the deflection until it reaches 7 to 8 mm (.28 to .31 inches).

Tips & Warnings

Check your belts monthly for wear. Replacing a worn belt before it breaks can avoid an annoying breakdown.