Engine Mechanical (Vq): Adjustments Nissan Frontier D40

Tension Adjustment

Belt tensioning is not necessary, as it is automatically adjusted by the drive belt auto-tensioner.

Scheme 236

1. Remove air duct and resonator assembly (inlet). Refer to " «REMOVAL»(ref-272352-S25129190762007111800000) ".
2. Rotate the drive belt auto-tensioner in the direction of arrow (loosening direction of tensioner) as shown, using suitable tool. CAUTION: Avoid placing hand in a location where pinching may occur if the tool accidentally comes off.
3. Remove the drive belt. see scheme 8: Identifying Drive Belt Rotational Direction

ADJUSTMENT

1. Perform adjustment depending on selected head thickness of valve lifter.

Scheme 237

Scheme 238

1. Measure the valve clearance. Refer to " «INSPECTION»(ref-272352-S25536247062007111800000) ".
2. Remove camshaft. Refer to " «REMOVAL»(ref-272352-S42635948002007111800000) ".
3. Remove valve lifters at the locations that are out of the standard.
4. Measure the center thickness of removed valve lifters with micrometer. see scheme 188: Checking Center Thickness Of Removed Valve Lifters With Micrometer
5. Use the equation below to calculate valve lifter thickness for replacement. Valve lifter thickness calculation: t = t1 + (C1-C2) t = Valve lifter thickness to be replaced t1 = Removed valve lifter thickness C1 = Measured valve clearance C2 = Standard valve clearance: Intake: 0.30 mm (0.012 in)* Exhaust: 0.33 mm (0.013 in)* *: Approximately 20°C (68°F) Thickness of new valve lifter can be identified by stamp marks on the reverse side (inside the cylinder). see scheme 189: Checking Thickness Of Valve Lifters INTAKE SPECIFICATIONS Stamp mark Thickness 788U 7.88 mm (0.3102 in) 790U 7.90 mm (0.3110 in).... 840U 8.40 mm (0.3307 in) Available thickness of valve lifter: 27 sizes with range 7.88 to 8.40 mm (0.3102 to 0.3307 in) in steps of 0.02 mm (0.0008 in) (when manufactured at factory). Refer to " «AVAILABLE VALVE LIFTER»(ref-272352-S00223080852007111800000) ". EXHAUST SPECIFICATIONS Stamp mark Thickness N788 7.88 mm (0.3102 in) N790 7.90 mm (0.3110 in).... N836 8.36 mm (0.3291 in) Available thickness of valve lifter: 25 sizes with range 7.88 to 8.36 mm (0.3102 to 0.3291 in) in steps of 0.02 mm (0.0008 in) (when manufactured at factory). Refer to " «AVAILABLE VALVE LIFTER»(ref-272352-S00223080852007111800000) ". CAUTION: Install identification letter at the end and top, "U" and "N", at each of proper positions. (Be careful of mis-installation between intake and exhaust.)
6. Install selected valve lifter.
7. Install camshaft. Refer to " «INSTALLATION»(ref-272352-S42510278182007111800000) ".
8. Manually turn crankshaft pulley a few turns.
9. Make sure that the valve clearances for cold engine are within the specifications by referring to the specified values.
10. Installation of the remaining components is in the reverse order of removal.
11. Start the engine, and check for unusual noise and vibration.

Scheme 239

Scheme 240

1. Turn crankshaft until the cylinder requiring new oil seals is at TDC. This will prevent valve from dropping into cylinder.
2. Remove camshaft relating to valve oil seal to be removed. Refer to " «REMOVAL»(ref-272352-S42635948002007111800000) ".
3. Remove valve lifters. Refer to " «REMOVAL»(ref-272352-S42635948002007111800000) ".
4. Remove valve collet, valve spring retainer and valve spring using Tool. CAUTION: When working, take care not to damage valve lifter holes. Tool numbers: KV10116200 (J-26336-B): KV10115900 (J-26336-20): KV10109220 ( - ) Compress valve spring using Tool attachment, adapter. Remove valve collet with magnet hand. see scheme 190: Compressing Valve Spring Using Tool Attachment
5. Remove valve oil seal using Tool. Tool number: KV10107902 (J-38959) see scheme 191: Identifying Valve Oil Seal

Scheme 241

1. Apply new engine oil to new valve oil seal joint surface and seal lip.
2. Press in valve oil seal to height "H" using Tool to specified height. Tool number: - (J-39386) NOTE: Dimension "H": height measured before valve spring seat installation. Intake and exhaust: 14.3-14.9 mm (0.563-0.587 in)
3. Installation of the remaining components is in the reverse order of removal. see scheme 192: Identifying Valve Oil Seal Height

Scheme 242

1. Remove engine undercover using power tools.
2. Remove drive belts. Refer to " «REMOVAL»(ref-272352-S20981100952007111800000) ".
3. Remove engine cooling fan assembly. Refer to " «ENGINE COOLING FAN»(ref-272353-S32715010432007111800000) ".
4. Remove crankshaft pulley. Refer to " «REMOVAL»(ref-272352-S32655962482007111800000) ".
5. Remove front oil seal using suitable tool. CAUTION: Be careful not to damage front timing chain case and crankshaft. see scheme 193: Identifying Front Oil Seal