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

otate the engine once, those paint marks are no longer relevant. 9) Tensioner efficiency:
Before you take off the tensioner and the timing belt, take a moment to notice the tension on the
belt between the exhaust cam and the water pump. It seems to move about 1/4 inch with about
10 lbs lateral pressure. This is purely a guess based on what I thought it felt like. 10) Remove
the tensioner by a) slacking the two 12 mm bolts, b) removing the upper bolt, c) rotating the
tensioner clockwise a little, d) removing the bottom bolt and lifting out the tensioner. [Tip from
Vic Lind] If you are trying to remove the tensioner pulley, it is held on with a Torx T-45 bolt but
using a shallow hole. If you cannot get this off, try applying penetrating oil to the bolt then use a
pipe wrench on the outer washer. This will move and in turn move the stuck bolt. 11) Remove
the timing belt by first removing the two 10 mm bolts that hold the plastic housing on the top of
the shroud at the top on the engine. No need to actually remove this top shroud. With the bolts
out it can be moved enough to get the belt out. Remove the belt off the cams. Then get under
the car and very carefully work the belt off the crankshaft gear. ...remembering how you got it
off because it's like a Chinese puzzle to get the new belt back on. 12) Take a good look at the
tensioner assembly. It is an hydraulic affair and it should not be leaking oil. If it is leaking you
need to replace it. That tensioner fails the belt will jump cogs and the motor will be destroyed.
13) Compress the plunger back into the tensioner. First remove the white nylon positioning
ring. Line up the three little holes so you can place the keeper through them to allow you to
reinstall the tensioner. A vice would work well to compress the tensioner. My vice was not large
enough so I used a 6 inch C clamp. Compress the plunger a quarter turn at a time allowing it to
'rest' between twists. When the plunger is all the way flush with the housing push a 3 penny
common nail into the hole with the head of the nail facing out so you can pull the nail out when
the tensioner has been reinstalled. Place the nylon guide washer back on the tensioner. A new
one probably came with the new timing belt. See notes and diagram above about correct
orientation. 14) Inspect all the idlers for smooth operation. Inspect the water pump for leaks.
This is the time to change the water pump if it isn't in good shape. 15) Install the new belt. I
found it was easiest to snake the belt down to the crankshaft gear before trying to place it on
any of the other gears or idlers. Crawl under the car with a good light to work the belt on to the
crankshaft gear without crimping it in any way. Once it's on the crankshaft gear, then put it on
the intake cam and remove all the slack between crank and intake cam gear. Then do exhaust
cam and then water pump and finally the idlers where the tensioner goes. You want all the
slack at the tensioner idlers. 16) Install the tensioner. Tougher than it first looks. There's not
much room between the tensioner and the fan for fat fingers. Locate the top bolt first and get it
started. Then do the bottom one. Make sure the tensioner seats itself flush on the front on the
engine and torque it down. Volvo says 18 ft pounds (25 Nm). I couldn't get a torque wrench in
there. Regardless, that's not a lot of torque. 17) Critical point: carefully inspect all your timing
marks. Is there slack anywhere except around the tensioner? Is the belt fully seated on each
gear? If everything's OK, take some pliers and pull out the 3 penny nail that has been holding in
the plunger on the tensioner. It comes out fairly easy. The tensioner will ease itself back into
position and will take up all the slack on the tensioner side of the engine. Inspect by feeling the
tension between the exhaust cam and the water pump. Does it feel about as it did before you
took the belt off. Are the timing marks still where they are supposed to be? 18) Crawl
underneath to make sure the belt is seated on the crankshaft gear. If it is in place, reinstall the
vibration damper guard. Reinstall the splashguard that covers the oil filter. 19) Reinstall the two
10 mm bolts that hold the top of the cam belt shroud on the top of the engine. 20) Volvo
recommends you make the crank turn two complete revolutions to make sure all the timing
marks are still in place. That's more difficult than it sounds. I skipped that step and crossed my