We replace the camshaft due to wear on the camshaft journals and cams. If the camshaft journals are badly worn, there will be a low pressure in the engine lubrication system
Increased wear on the camshaft cams will cause valve knocking, which cannot be eliminated by adjusting the valves.
If the camshaft seats are badly worn, then completely replace the cylinder head, because they are made directly in the head body.
We prepare the car for the job.
We install the car on a lift.
Disconnect the negative terminal of the battery.
We remove the engine, because there is no access to the camshaft sprocket, due to the layout on the GAZelle Next car.
Removing the vacuum pump
Remove the cylinder head cover (article - Replacing the cylinder head cover gasket for the Cummins ISF2.8 engine).
We set the TDC of the first cylinder in the compression stroke (article - Setting the TDC of the first cylinder Cummins ISF2.8).
We unscrew the five bolts securing the crankcase cover of the timing drive and remove the cover
Unscrew the two bolts securing the chain tensioner cover
Remove the cover and remove the plunger
We fix the chain by tying it with a wire
We loosen the tightening of the mounting bolt of the drive disc and the camshaft sprocket
We completely unscrew the bolt securing the phase sensor disc and the camshaft sprocket
Do not turn the crankshaft after unscrewing the mounting bolt of the drive disc!
Removing the master disk
Remove the sprocket with the chain from the camshaft shank
Removing the spacer washer
We unscrew the bolts of the rocker arm axles
We remove the bolts from the axles of the rocker arms
Removing the rocker arms
Removing the valve lifters
We take out the supports of the axles of the rocker arms
We mark all the details
Do not remove the tip from the adjusting bolt. If it is damaged, then the rocker arm must be replaced.
We inspect the rocker arms
Inspecting the pushers
There should be no cracks or signs of wear in the rocker arm holes under the axle.
The hole diameter should be no more than 21.014 mm.
The rocker roller should rotate freely on the axis and not have dents on the working surface.
We check the pushers for cracks and signs of wear.
We unscrew the two bolts securing the camshaft retaining plate
Removing the plate
We take out the camshaft carefully, trying not to damage the working surfaces of the bearings
Inspecting the camshaft
The surfaces of the bearing journals "B" and cams "A", Figure 23, must be well polished and free from damage, and there must be no traces of excessive wear and nicks in the groove "B" under the lock plate.
On the working surfaces of the necks "B", scuffs, nicks, scratches, aluminum enveloping 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 "A", as well as uniform wear over 0.5 mm, replace the shaft.
Grinding of the camshaft cams is not permitted.
We measure the height of the cams.
The minimum permissible height of the intake cams is 34.51 mm, the exhaust cams are 33.41 mm. At lower values, we replace the camshaft.
Measure the diameters of the bearing journals.
The minimum permissible diameter of the 1st to 4th neck is 42.955 mm, of the 5th neck - 38.955 mm. If the value is lower, replace the shaft.
The radial runout of the camshaft should be no more than 0.02 mm.
When installing a new camshaft, we recommend replacing the rocker arms with new ones, and before starting the engine for the first time and to improve the running-in conditions, add an extreme pressure antifriction additive to the engine oil.
After installing the camshaft, check its axial clearance. If it is more than 0.15 mm, replace the lock plate.
Install the camshaft in the head of the block and all removed parts in the reverse order of removal.
Adjust the valve drive clearances (article - Adjusting the thermal clearances of Cummins ISF2.8 valves).
Install the engine to the vehicle.
