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Timing Belt 93 850 Question re/ CAM lineup

Help, Advice and DIY Tutorials on Volvo's P80 platform cars -- Volvo's 1990s "bread and butter" cars -- powered by the ubiquitous and durable Volvo inline 5-cylinder engine.

1992 - 1997 850, including 850 R, 850 T-5R, 850 T-5, 850 GLT
1997 - 2000 S70, S70 AWD
1997 - 2000 V70, V70 AWD
1997 - 2000 V70-XC
1997 - 2004 C70

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paulfr
Posts: 23
Joined: 30 August 2007
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Timing Belt 93 850 Question re/ CAM lineup

Post by paulfr »

Finishing up replacing the water pump on a 93 850na. I did the belt not too many miles ago and being me, stupid, I didn't replace the pump at that time. Now I've replaced pump and tensioner but the damn belt (which is in excellent condition) has been a problem to get back on. Finally after a long hour on a very hot day I got the belt on but The Concern is the exhaust cam is 1/2 a tooth off from The Mark; peak to valley being 1/2 and peak to peak = 1. I seem to recall reading here or perhaps elsewhere that a half notch is no big deal. What has been the experience of the readers herein?

The job is ON Hold

Paulfr

Pauloil
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Location: davenport, IA

Post by Pauloil »

be sure the crank mark is spot on, then look up top at the cams. I did it this way on my 99V70xc, and could then see the intake cam was a tooth off. I don't see how could be 1/2 tooth off, assuming you have released the tensioner and spun it around.
99 V70XC 158K

95 850glt 188K

JimBee
Posts: 1915
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Year and Model: 93 and 2 96 850's
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Post by JimBee »

If the belt is really tight from the crank sprocket to the intake cam sprocket (you'll need a lever of some sort to get it that tight—hand tightening won't do it), and tight across to the exhaust sprocket, when you pull the pin, it's still going to move a bit CCW on the exhaust sprocket. That might be your 1/2 tooth. You probably want it 1/2 tooth CW past the mark before you pull the pin for that reason. If it's not twang tight across between the sprockets you could get more than a tooth CCW turn on your exhaust sprocket. Then you take off the tensioner and try again.
Make sure you scribe some sort of reference mark across your harmonic damper, with Sharpie marker or something, so you can tell at a glance if it has moved. I use a short 6" level, set across the damper and scribe the line. That way I can just put the level back on the line and see if it's level. If the line isn't level, your crank moved off the mark. You can pull pretty hard on the intake sprocket before the crank will turn. IOW, you can get the belt twang tight without turning the crank. But you do need to be able to eyeball a quick and accurate check to make sure the crank doesn't turn.

WATER PUMP: just a suggestion. When I did '93 850 water pump last August, I tightened all the bolts in criss cross pattern, going around several times. It was nightfall and I was working outside so I left it there. Before putting the belt on the next day, just for the heck of it I put a wrench on those bolts and got an easy half to 3/4 turn on each one before they felt just right tight. I've never had a leak. I'd suggest doing the same.

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