Volvo Maintenance Hints for 7xx/9xx - Bill Garland's Nuclear ...

marks. Make sure the guide washers are oriented correctly on the lower timing
gear on the crankshaft.
13. Stretch timing belt on tension side and fit timing belt on camshaft sprocket and
tensioner roller. Make sure timing belt is correctly installed and sprocket marks line
up with marks on engine.
14. Tension timing belt: Release the belt tensioner by loosening the nut or pulling out
the nail. Tap the tensioner flange with a hammer to ensure it is seated in its
mounting holes. Tighten the tensioner nut. Loosen tensioner nut approx. 1 turn to
let it tension timing belt. Then tighten tensioner nut again to 37 ft-lbs.
15. If this is your first belt change, use Whiteout or white paint to highlight the timing
belt marks on the inner timing belt cover and make the next change easier..
16. Clean and install timing belt lower cover. Install crankshaft pulley vibration
damper. Make sure that the dowel (guide pin) on the sprocket engages with the
hole in the pulley. [Editor: See Timing Belt Tips to help ensure the damper pin is
engaged.] Use special tool 5248 to hold. [Editor's Note: See Bolt, Two Caveats
first.] Use special tool 5284 or secure the flywheel and tighten the pulley bolt to the
specified torque which is 44 ft-lb (60 Nm) PLUS an additional 1/6 turn, or 60
degrees.
17. Clean and install upper timing belt cover.
18. Install: clips for preheater hose, fan, fan shroud and drive belts. Check that ignition
timing is correct.
19. Run Engine Run engine until it reaches normal operating temperature while
checking operation. Then stop engine.
20. Readjust timing belt tension. Remove rubber plug from cover. Release belt
tensioner nut approx. 1 turn to let tensioner spring stretch timing belt. Rotate
engine clockwise at least one half turn to top dead center (TDC) using crankshaft
bolt in order to properly position the tensioner. Retighten nut to 37 ft-lb (50 Nm)
and install rubber plug in cover. If a new belt has been installed, repeat this retensioning
after approximately 600 miles (1000 km).
3. Plate and Pulley Tensioner Re-Assembly. [Inquiry:] I got the crank pulley on my 91 740 off
finally, retimed the sprockets and the crank is on TDC. I now need to reassemble everything.
The first question I have is which guide plate goes in first. There are two: one has a u- shape
hole on the edge, and the other has two holes on the edge, a rectangular shape hole, and an
additional small notch on the opposite side. Which plate goes in first?
[Response: Don Foster] You'll notice that the washers or "guide plates", as you call them, are
flared or beveled or dished or bell-shaped -- pick your descriptive term. They must be oriented
so the flare is away from the belt like this ")B(". Otherwise the sharp edge will quickly abrade the
belt.
First, slide one "plate" over the crank. I think the plate with a notch fits over the woodruff key. Be
sure the "dish" is toward the engine. Then fit the crank sprocket, again over the key. Then
install the timing belt, taking all the previously-mentioned precautions to align timing marks on
belt, sprockets, and block. Release the tensioner to hold the belt against the sprockets.
Install the outer "guide plate", nearest you (this one dies not need to fit over the key), assuring
the "dish" is outward (toward you) so it won't cut the belt. It has no orientation, other than dishedout.
(And the inner plate has a keyway simply so it'll fit over the key -- it doesn't otherwise need