Nissan 13231-1KC0A Lifter-Valve

A new camshaft oil seal and appropriate sealant to fix the new bearing caps for the camshaft and Cylinder head cover are required. This is usually required for the lash adjusters or completely during the overhaul of the cylinder head where the head, cylinder head cover, camshaft sprocket, brake vacuum pump are removed. The temper of the camshaft is ascertained with a dial gauge ending on the camshaft thrust washers which shows the wear. If the initial camshaft is going to be reused, valve clearances should be checked so that the desired adjuster thicknesses are taken as required. It should be remembered that such features as identification marks on the camshaft bearing caps must be matched when reinstalling; the bearing cap bolts must be gradually loosened to eliminate pressure on the valve springs. The camshaft can then be lifted out along with the oil seal, which proved to have to be removed as well. Lash adjusters need to be stored so they can easily be put back on and any wrong valve clearances need to have the adjuster thickness measured. Indeed, such features as cam bearing surfaces, lobes, cam, and shaft must be inspected for damages and wear, checking the camshaft run out and lobe height. It is also necessary to check the bearing oil clearance and re-attach the bearing caps with identification marks and tightened bolts to the corresponding torque. If any one journal is worn beyond the limits, the cylinder head must be replaced. The lash adjusters should be oiled and re-installed back in their prior positions; the next step is to oil the camshaft journals before fitting the camshaft onto the cylinder head. Before fitting the bearing caps or tightening the bolts, the sealant must be applied to the end cam shaft bearing cap contact surfaces. When a new camshaft is installed, end float has to be checked and adjusted by turning the camshaft sprocket after which, the oil seal is fitted new, finally the brake vacuum, the camshaft sprocket, and the cylinder head cover are reinstalled.

Begin by removing the timing chains and camshaft sprockets, then detach the camshaft position sensor brackets from the driver's ends of the cylinder heads.