500SEC (140.070) V8-5.0L (119.970) (1993)
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17
compression spring
18
Control piston
22
Camshaft
23
Oil return hole
Above 4700 rpm (retarded)
The adjustable camshaft timing solenoid (Y49) has no voltage applied and releases the control piston. The control piston (18) is driven by the
compression spring (17) against the retaining ring (19). The oil supply passage to working chamber "B" is closed off, and the passage to working
chamber "A" is opened through the 2 holes in the flanged hub (16). The control piston (18) is moved against the cover (12) by the engine oil pressure.
This axial movement of the adjustment piston (14) turns the camshaft (22), bolted to the flanged hub (16), to the "retarded" position. The camshaft
retard results from the effect of the helical teeth in the camshaft sprocket (13), the adjustment piston (14), and flanged hub (16). At the same time
engine oil in working chamber "B", pushed by the adjustment piston, runs out through the 2 holes in each of the adjustment piston (14), the flanged
hub (16) and the control piston (18) and the two holes (23) in the camshaft flange (22).
Assembly note
The individual parts of the camshaft timing adjuster can be assembled together only in one specific, predetermined sequence.
The solenoid is sealed to the cover with a sealant.
Testing
See Diagnostic Manual, Engine.
4
Armature
6
Nut
12
Cover with ring insert
13
Camshaft sprocket
14
Adjustment piston
16
Flanged hub
18
Control piston
22
Intake camshaft
Idler sprocket
The idler sprocket (1) with its bushing is mounted on a hardened journal (2) and is guided axially by the timing chain.
The hollow-bored journal with 2 oil passages to the bushing surface is mounted in the cylinder head and fastened with a left-hand-thread screw (3).
Timing chain, guide and tensioning rails
