2.8.19. Removal and installation of cam-shafts

Fig. 2.381. Components of the valvate mechanism: 1 – final valve; 2 – cap; 3 – head of the block of cylinders; 4 – basic element; 5 – safety bracket; 6 – inlet cam-shaft; 7 – cam-shaft frame; 8 – bolt of 9 N · m; 9 – final cam-shaft; 10 – roller lever; 11 – checks of the valve; 12 – plate of a valve spring; 13 – valve spring; 14 – oil scraper cap; 15 – inlet valve



Check of axial shift of cam-shafts

Fig. 2.382. Check of axial shift of cam-shafts



You take measurements at the removed roller levers and basic elements.
Fix a universal support of a micrometer with a micrometer on GBTs.
Determine axial shift.
Axial shift: 0,100–0,191 mm.

Removal
Uncover GBTs.
Uncover left and right a driving chain.
Remove the chain drive from cam-shafts.
For removal of cam-shafts of the right GBTs it is necessary to dismantle the vacuum pump of the amplifier of brakes.

Fig. 2.383. Sequence of weakening of bolts of a frame of a cam-shaft


Weaken cam-shaft frame bolts in the sequence of 22-1 (fig. 2.383).

NOTE
In the drawing the frame of a cam-shaft of the left GBTs is shown.

Carefully remove a cam-shaft frame.
Mark and remove cam-shafts.

Installation
Remove the sealant remains on GBTs and a frame of a cam-shaft, for example, by means of a drill with the clamped brush with a plastic bristle.

NOTE
Laying and sealing rings needs to be replaced.
The crankshaft has to be fixed by the fixing bolt.

ATTENTION
You watch that the remains of sealant did not get to GBTs and bearings.

Clear landing surfaces; on them there should not be an oil and lubricant.
Oil working surfaces of cam-shafts engine.
Put a cam-shaft frame on a workbench, having enclosed a soft lining.

Fig. 2.384. The scheme of laying of cam-shafts in a frame


Lay cam-shafts in a frame (fig. 2.384).
Cam-shafts have to lie accurately in axial bearings of a frame.
Cams of 1 and 2 valves have to be sent up or down, by no means not aside (fig. 2.384).
Turn a cam-shaft frame with the cam-shafts established on it, strongly holding them at the same time.

Fig. 2.347. Provision of carving openings


Turn cam-shafts until carving openings adopt the top provision (fig. 2.347).
Check whether cam-shafts accurately in axial bearings of a frame lie.

Fig. 2.348. Installation of clamps of cam-shafts


Establish a clamp of cam-shafts, as shown in the figure 2.348, and tighten bolts with the moment of 20 N · m.
Cut off a tube nose on a forward mark (diameter of an opening about 1 mm).
Again turn a frame of cam-shafts.

Fig. 2.385. The scheme of laying of sealant on a frame of cam-shafts


Put a small amount of sealant in a flute of laying 3 in a zone of opening of the electromagnetic valve of system of adjustment of phases of gas distribution (fig. 2.385).
Establish laying in a frame of a cam-shaft and remove the following sealant on laying and a frame of cam-shafts.
Apply rollers of sealant 1, 2 and 4 on pure landing surfaces of a frame of cam-shafts, as shown in the drawing.
Sealant roller thickness: 1,0 mm.

NOTE
Rollers of sealant should be put in accurate compliance with the instruction, otherwise sealant can get to bearings of cam-shafts.

At once establish a frame of cam-shafts on GBTs.

NOTE
It is necessary to establish and fasten a frame of cam-shafts without delay as sealant quickly hardens.

After installation of a frame of cam-shafts let's dry to sealant about 30 min.
Fasten cam-shaft frame bolts in the sequence 1–22 at first by hand (fig. 2.383).
The frame of cam-shafts has to lie on GBTs on all surface area.
Tighten cam-shaft frame bolts in the sequence 1–22.

NOTE
In the drawing the frame of a cam-shaft of the left GBTs is shown.

Establish caps aflush.
Further installation is carried out in the return sequence.

NOTE
After installation of cam-shafts the engine it have to is impossible to bring Gidrokompensatora within about 30 min. to be besieged (otherwise valves will be adjoin to pistons).

After works on the valvate mechanism scroll the engine by hand not less than two turns that be convinced that any valve does not adjoin to the piston.
Install the vacuum pump of the amplifier of brakes.
Install the chain drive of cam-shafts.
Establish covers of the left and right driving chains.
Establish GBTs covers.

Inhaling moment
Cam-shaft frame to GBTs: 9 N · m.