Lincoln 7T4Z-6A257-B Camshaft Position Sensor

Reinstall the crankshaft sprocket bolt and set the engine to TDC for cylinder number 1. These engines have three timing chains: The long primary chain drives the VCT sprockets (on each intake camshaft) and the water pump, while a smaller chain on each head drives the exhaust camshafts. Install the special camshaft holding tools (manufacturer tool no. 303-1248) on each cylinder head to lock the camshafts in the TDC position. Remove the VCT assembly mounting bolts from the rear cylinder head, then the front cylinder head. Remove the bolts, then remove the primary timing chain tensioner and tensioner arm. Remove the lower chain guide from the front cylinder bank. Mark the chain links opposite the timing marks on the camshafts (if not already marked), and remove the primary timing chain. Remove the upper chain guide from the front cylinder bank. If necessary, remove the crankshaft sprocket. If the secondary timing chains and camshaft sprockets are to be removed for inspection or another procedure, compress the tensioner(s) and insert a pin into the hole in the tensioner to hold it in the retracted position. Unscrew the bolts for the intake (VCT) and exhaust camshaft sprockets, then remove both sprockets and the chain as an assembly. Caution: Make sure the camshaft holding tool is in place and prevents the camshafts from turning while unscrewing the bolts. Also, new bolts must be used for reassembly. Remove the bolts and the secondary chain tensioners.

Remove the timing chain cover. Reinstall the crankshaft sprocket bolt and set the engine to TDC for cylinder number 1.

If the primary chain gear and its plate were removed, clean the mounting surface and the block, then install the sprocket and plate with a new gasket. Prepare the primary chain tensioners by pushing in the release button and compressing the plunger until a nail or large paper clip can be inserted to hold the plunger. If the secondary timing chain tensioners were removed, they cannot be reused. New tensioners must be installed. The tensioner is installed to the correct depth when you hear a snap. Install the tensioner shoe. The plastic clip can now be removed with pliers. Align the colored links with the marks on the VCT units and install the chain.

Install the upper chain guide on the front (left) cylinder bank, tightening the bolts to the torque specifications.