Lexus 13801-23011 Arm Sub-Assy, Valve Rocker, NO.1

For the removal procedure it is suggested that the engine and transaxle assembly must be removed. This is not a task for the novices so it is recommended to read the entire procedure before attempting it. The process of this work includes, for example, the removal of the engine oil and the engine coolant in the first step and subsequent removal of the timing chains or-more precisely-the timing sprockets. To access Intake cam lobe for No.1 cylinder: align the pointer to the 12 O'clock position- for the exhaust cam lobe align pointer to 3 O'clock Before removing the bearing cap bolts and housing bolts, these must be loosened in a sequence that is quite the reverse of the tightening order. Bolt and nut the camshafts and keep all the parts collectively. For 2GR-FKS engines, make sure the marks are in TDC position and then remove the camshaft timing gear bolts to remove the sprockets. Before releasing the bearing caps clear the intake camshaft locating pins, and to release the bolts do so in sequence starting with the last. Insert a spanner under the camshaft housing and pull it off the cylinder head while unbending the rocker arms and the lash adjusters and make sure they are placed in order. Check every rocker and lash adjuster for signs of wear, look closely at the cams for any possible damage to the cam lobes and the bearing journals, and determine the height of each of the camshaft's lobe and the diameter of the every journal. Use Plastigage to check the oil clearance of every camshaft journal and; if the measurement is not within the required limits, then the camshaft has to be replaced. For installation, lubricate the lash adjuster bores and the adjusters and position them with the original position of the rocker arms. The camshaft journals and lobes should be lubricated and the camshafts should be installed, the mating surfaces of the camshaft housing assembly should be coated with RTV silicone sealer before the camshaft housing is installed. After that, turn all bolts marked on the assembly with tightness to one another in the prescribed order to the required torque. The remaining steps of the installation process go in the reverse order of the removal, and one has to make sure to rotate the crankshaft to feel for any resistance after; the engine is refueled with oil and coolant; the battery is reconnected and the engine is started to see if there are any signs of leakage.

The manufacturer recommends removing the engine and transaxle assembly before starting this procedure. This procedure is not recommended for beginners or those with limited experience.

Visually examine for score marks, pitting, galling, and evidence of overheating. Measure the height of each camshaft lobe with a micrometer.