Removal, troubleshooting and installation of the ZMZ-402 camshaft
Remove the fan drive belt.
Remove the alternator drive belt.
Remove four screws 1, remove fan 2 and fan pulley 3.
Unscrew the four bolts 4 and remove the water pump pulley 5.
Unscrew the three nuts 2 and remove the fan drive 1.
Unscrew bolt 3 and nut 5, remove bracket 4 with tension roller.
Remove six bolts 7 and remove crankshaft pulley 6 with vibration damper assembly.
Unscrew the coupling bolt 8 (or ratchet) with a puller
Remove the crankshaft pulley hub.
Unscrew the remaining nuts 1 and remove the cover 2 of the timing sprockets.
Install the piston of the 1st cylinder at TDC. compression stroke.
To do this, turn the crankshaft so that the marks on the crankshaft sprocket and the camshaft gear are aligned.
Remove the ignition distributor drive.
Remove the oil filter.
Remove the fuel pump.
Remove rocker cover.
Remove the valve rocker shaft with strut assembly.
Remove the pusher rods, after marking them with the valve number.
Unscrew the nuts 1 and remove the cover 2 of the pushers together with the gasket.
Remove pushrods 1.
Remove bolt 1 and remove camshaft gear 2 with a puller.
Remove bolts 3 and remove the camshaft thrust flange with spacer sleeve.
Carefully remove the camshaft from the cylinder block.
Inspection and Troubleshooting
After removing, wash all parts with gasoline, wipe and dry.
Inspect the camshaft. If there are scuffs, deep scratches, shells, chips, cracks on the necks, cams and gear of the oil pump drive, replace the camshaft.
Measure the diameters of the camshaft journals, the nominal diameters of the journals are indicated in the table.
Inspect the push rods. Replace bent rods.
If there are signs of wear, scuffing, shells on the tips of the rods, also replace the rods.
It should be noted that the length of the engine rod mod. 402 is 283 mm, and the engine mod. 4021 - 287 mm.
Inspect the pushers. If there are signs of wear, pitting, scuffing, etc. on the working surfaces, replace the pushers.
If the teeth on the camshaft gear are damaged or cracked, it must be replaced.
Measure the camshaft end play.
To do this, assemble the shaft with a gear wheel, put a spacer ring and a thrust flange on the front end of the camshaft, then press the gear wheel and tighten the gear wheel mounting bolt with a washer.
Tighten the bolt to 55–60 Nm (5.5–6.0 kgf m).
Measure the gap between the thrust flange of the camshaft and the hub of the gear wheel with a feeler gauge, it should be within 0.1–0.2 mm.
Install the camshaft in the reverse order of removal.
Before installing, lubricate the camshaft journals and cams, tappets and pushrods with engine oil.
After installation, adjust the clearances in the valve drive.
Nominal dimensions and fit of mating parts of the camshaft of the engine mod. 402