Installing The Toothed Belt 251Dohc, Aq171 - Volvo Penta 230 Workshop Manual

Installing the toothed belt 251DOHC,
AQ171
191. Inspect the belt tensioner. There should be no
play in the bearing. If the contact surface of the roll-
er is damaged, the roller and the belt must be re-
placed. Fine-adjust the camshaft gears and the
crankshaft gear so that they will line up exactly with
the respective markings on the valve cover and the
seal holder behind the torsional damper.
192. Install the belt so that the yellow (lines) mark-
ings align as follows:
2 lines against the crankshaft gear marking and 1
line against each of the camshaft gear markings. For
the crankshaft gear marking, the belt has to be de-
pressed somewhat into the correct tooth gap for
checking. Also see under 250, AQ151).
NOTE! For the 250, AQ151 the belt must be in-
stalled on the belt tensioner prior to being installed
on the camshaft gears, this because the belt ten-
sioner is provided with guiding edges.
Check carefully that the belt is installed so that the
markings line up.
NOTE! It is not necessary to adjust the marking of
the intermediate wheel against the belt marking.
193. Turn the belt tensioner to tension the belt and
then tighten the Allen-head screw. Tool width: 8 mm.
The belt must be tensioned at least once per season
and be replaced after every 500 hours of operation.
194. Method 1: Correct belt tension. Turn the crank-
shaft a few degrees counter clockwise and check
that the marking on the belt (2 lines) coincide with
the marking on the guide plate. Then turn the crank-
shaft a few turns clockwise. Take the belt between
the index finger and the thumb and twist it. It should
be possible to twist the belt 90° by hand. Increase or
decrease the belt tension, should the belt not be ten-
sioned correctly.
195. Method 2: Tension the belt and place special
tool part no 1159660-8 on the belt. 'Zero' the instru-
ment by depressing the lever (1). Then press the
tool against the belt until a 'click' is heard. Note the
value of the tool. The correct value should be 20 to
25 Kilos (44–55 lbs). Tension or loosen the belt as
required.
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