Description And Operation
The timing cover is attached to the crankcase, to the cylinder heads and cylinder heads via bolts (blue) and studs (green).
There is an opening in the central part of the timing cover where the spacer mounted on the camshaft is housed.
- Oil seal
- Crankshaft spacer
As noted in the image, there is an oil seal between the timing cover and the spacer. There is also a roller bearing between the cover and the spacer.
The ball bearing is held in its place in the tappet cover by two small containment plates (shoulder plates).
- Roller bearing (A).
- Retaining brackets (B).
There is a metal gasket between the timing cover and the engine. The gasket is not reusable. The fasteners holding the cover to the engine must be tightened in a precise sequence. Failure to follow the correct tightening sequence could create a non-uniform load on the roller bearing, creating noise during engine operation.
Components in the interface area between the crankshaft and the timing cover.
- Timing cover (1).
- Oil seal assembly (2).
- Roller bearing (3).
- Roller bearing retaining bracket (4).
- Spacer (5)
- Ball bearing (6).
The ball bearing is inserted inside the crankshaft and supports the transmission input shaft (7).
Timing Components
- Crankshaft sprocket (1).
- Primary timing chain (2).
- Left chain guide (3)
- Right primary chain guide (4)
- Left camshaft chain guide (5)
- Hydraulic tensioner left side (6).
- Left bank camshaft chain (7).
- Left bank camshaft phasers (intake and exhaust) (8)
- Left bank chain guide (9).
- Upper primary sprocket (10).
- Camshaft gear of left and right timing chains (11).
- Right side camshaft chain guide (12).
- Right bank camshaft phasers (intake and exhaust) (13).
- Right bank camshaft timing chain (14).
- Right bank hydraulic tensioner (15).
- Right camshaft chain guide (16).
The primary sprocket on the crankshaft integrates the two gears, one of which is dedicated to the timing and the other to the oil pump control.
- Hole for the spacer retaining screw.
- Opening for gear to be connected to the crankshaft.
- Teeth for timing chain.
- Teeth for oil pump chain.
The screws that fasten the gear to the crankshaft are the same as those that fasten the flywheel. The gear can be fastened to the crankshaft in one position only.
The crankshaft gear sends the motion via a chain to the upper sprocket placed in the center of the crankcase.
The upper sprocket has two other smaller gears through which the motion is sent to the camshaft timing chains.
- Left bank camshaft timing (1)
- Right bank camshaft timing (2)
The upper sprocket is clamped onto a pin fastened to the crankcase center. The pin also acts as a cap to an engine oil timing chamber for the cylinder heads.
The gear's rotation is on two roller bearings.
The camshaft timing chains are kept under tension by their hydraulic tensioner. The tensioners are fastened by two screws on the cylinder heads and use engine oil from oil passages in the heads to create tension.
Oil inlet port (1)