Service Manual Book description :
Removal (Frontier, Pathfinder, QX4 & Xterra)
1. Disconnect negative battery cable. Remove the engine undercover. Drain coolant and remove the radiator.
Remove engine cooling fan and water pump pulley. Remove accessory drive belts. Remove spark plugs.
2. Remove distributor protector. Remove A/C compressor drive belt idler bracket. Remove fresh air intaketube from rocker cover. Remove thermostat housing hose.
3. Rotate crankshaft to set No. 1 cylinder at TDC on compression stroke. See Fig. 1 . Remove crankshaft
pulley bolt and remove crankshaft pulley. Remove front upper and lower timing belt covers. See Fig. 2 .
4. Align punch mark on left camshaft sprocket with punch mark on timing belt upper rear cover. Align
punch mark on crankshaft sprocket with notch on oil pump housing. See Fig. 3 . Install crankshaft pulley
bolt so that crankshaft can be rotated.
5. Loosen timing belt tensioner nut. See Fig. 4 . Turn tensioner, and remove timing belt.Inspection (Frontier, Pathfinder, QX4 & Xterra)
Check timing belt for cracks and broken or worn teeth. Check belt tensioner for smooth turning. Check condition of tensioner spring. Replace parts as necessary.
Installation (Frontier, Pathfinder, QX4 & Xterra) 1. Install timing belt when engine is cold. Ensure No. 1 cylinder is at TDC on compression stroke.
Crankshaft sprocket mark should align with mark on rear cover. See Fig. 5 . If removed, install timing belt tensioner and tensioner spring.
If stud for tensioner spring is removed, apply thread sealant to studthreads before installing.
2. Turn tensioner clockwise fully outward with hexagon wrench, and temporarily tighten lock nut. Align
White lines on timing belt with punch marks on camshaft sprockets and crankshaft sprocket. See Fig. 6 .
Point arrow on timing belt toward front belt cover. There should be 40 teeth between left and right
camshaft sprockets, and 43 teeth between left camshaft sprocket and crankshaft sprocket.
3. If engine was overhauled or reassembled (rocker covers removed), go to step 6 . If only the timing belt