The camshafts on the F4R and K4M engines are located at the top of the cylinder head. One shaft opens the intake valves and the other opens the exhaust valves.
Eight cams are made on each shaft.
A feature of the camshaft design is that the cams are pressed onto the tubular shaft.
The camshaft beds (six bearings for each shaft) are demountable - located in the cylinder head and in the head cover.
The camshafts are driven by a toothed belt from the crankshaft pulley.
On each camshaft, on the side of the toothed pulley, a thrust flange is made, which enters the groove of the cylinder head, thereby preventing axial movement of the shaft.
The camshaft pulley is not fixed on the shaft using a tight fit, a key or a pin, but only due to the friction forces arising on the end surfaces of the pulley and shaft when tightening the pulley nut. The toe of the camshaft is sealed with an oil seal put on the shaft journal and pressed into the socket formed by the surfaces of the cylinder head and the head cover.
To remove the camshafts, you will need tools: keys for 8, 10, 13, 16, socket heads for 10, 16, 18, 17, Torx E14, keys Torx T8, Torx T14, a bronze drift, an engine support, a clamp for installing a TDC, camshaft lock.
We prepare the car for the task.
We relieve the pressure in the power system (article - Replacing the Renault Duster additional fuel filter)
Disconnect the negative terminal of the battery
We drain the coolant from the cooling system (article - Checking and replacing the Renault Duster engine coolant)
Remove the accessory drive belt (article - Renault Duster accessory belt check and replacement)
We remove the timing belt, as described in the article - "Checking and replacing the timing belt of the Renault Duster car"
Disconnect the front pipe from the exhaust manifold (article - Removing elements of the exhaust system Renault Duster)
We remove the receiver (article - Removing and installing the receiver of the Renault Duster engine)
Remove the cylinder head cover (Removing the cylinder head cover of the Renault Duster engine)
Remove the exhaust camshaft
Remove the intake camshaft
We inspect the camshafts for wear and defects
The surfaces of the bearing journals "B" and cams "A" must be well polished and not damaged.
On the working surfaces of the journals, scuffs, nicks, scratches, aluminum envelopment from the bearing seats in the block head are not allowed.
If traces of galling, overheating, deep notches or wear in the form of a cut are found on the working surfaces of the cams, as well as uniform wear over 0.5 mm, the shaft must be replaced.
Thoroughly clean the oil supply channels from deposits.
Do not grind the camshaft cams to eliminate stepped wear, since the valve timing will be violated when the cam profile is resized.
Checking the radial runout.
If the runout is more than 0.02 mm, the shaft must be replaced, since it is not allowed to edit it.
Install the shafts in reverse order.
When installing new shafts, it is recommended to install new valve levers.
You can also see the article - "Removing camshafts and hydraulic valve support Renault Duster"