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156 TS 1.6 CF3 ENGINE SETTING CRANKSHAFT POSITION

1K views 14 replies 5 participants last post by  gerardsalfa 
#1 ·
How does one set the crankshaft in the right position when the camlocks are on and the cambelt is off?
I was changing cambelt and had set the engine to TDC using DTI put locks on but crankshaft accidentally got turned anticlockwise about 90 degrees not sure of the exact position it was at before belt removed and when guessing where that was and checking the DTI the needle was indicating the piston in no 1 cylinder was not at TDC and if I rotated the engine 30 degrees clockwise above my 'guessed' original position the needle was still going clockwise, but my 'guesstimate' couldn't be that far out, so unsure why DTI gave me the wrong original TDC if that's what has happened? Didn't take the crank round any further to see where the needle would stop as I was worried about interfering with valves as the camshafts are locked. So be glad of advice as to how to sort this one please? (By the way read on here that you can rotate the crank full 360 and the valves won't be affected even if the locks are on but don't want to chance that!). Just want to set the crank at the right position.
I can clearly see the crown of the piston in No1 sparkplug hole does that mean its definitely on the ignition stroke?
 
#2 ·
when rotating by hand you would need considerable force to damage valves,if you are rotating with a spanner and it stops due to valve impact just rotate backwards and it will be fine.
I seem to recall on the crankshaft pulley there is a mark that lines up at approx 11 o’clock to identify no1 firing. Put pulley on get crank in about right position then DTI so it’s exactly TDC.
 
#5 ·
With the tensioner relaxed the belt should slide on to the pulleys quite easily, and with the four bolts on the inlet pulley loose it can move to suit the teeth. If more than hand force is required there's something not quite right. Sometimes the tensioner needs a wee push to get it to slide away.
 
#6 ·
Thanks. I'm surprised the belt fitting is that easy as I've really struggled to get it round all the pulleys the only way so far is by removing the idler putting the belt on all the other components and then carefully fitting the idler which works but I'm not happy is the right way to do it. I've moved the cam sprockets left and right in attempts to lift the belt on with no change its dead tight.
The tensioner does slide ok and I've slackened all the bolts on everything right off but Ive found it really difficult to tension the belt using the alfa tool with the peg on the end the only way I can get it into the hole on the crankcase is by pushing the tensioner pointer round with a screwdriver then tightening the 13mm nut this gives clearance between the tensioner shoulder and the belt passing round the idler, but trying to get the tool out after releasing the tension on the belt so the pointer is over the reference hole creates the same problem there's then insufficient clearance to pull the tensioning tool out without dragging it over the belt you can get in and out no problem when the pointer is above the hole but obviously that's an over-tensioned position. The car was previously done by an alfa garage and I checked before removing the belt and to my surprise the pointer was above the hole so they must have had a similar problem. I don't understand what the marks are for on the belt itself as they don't line up with the crank and cam pulleys at TDC although a manual Ive read says they should and presumably alfa put them on for a reason.
 
#8 · (Edited)
I had an issue with a tool but it was years ago. I think I had to use emery paper or a bench grinder to dress up the peg of the tool so it fitted into the corresponding hole in the engine. I have also had some sort of issue on a very skimmed cylinder head whereby the cam on the tool was not large enough to move the tensioner far enough. I used a flat screwdriver to reduce the clearance to move the tensioner further over.

I can not make sense of the bit suggesting the belt is in the way.

If you continue to have issue, please post pictures.
 
#9 ·
Thanks I'll take some pictures and post them tomorrow. Essentially, as the tensioner slides inwards tensioning the belt the peg hole in the crankcase has got a lot of clearance round it so the peg slips in out easily, but when the tension is off the belt, the metal shoulder on the tensioner is too close to peg hole to get the peg in to apply tension and the lack of clearance persists unless the tension is increased so the pointer is above the hole. This makes it impossible to align the pointer over the hole using the special tool. I tried tools from 3 different kits the base of one of them is much slimmer than the other 2 which didn't work at all but, even with the slimmer one if I adjusted the tension to the recommended setting the gap between the shoulder and the belt where it passes over the idler was too tight to extract the tool without damaging the belt.
 
#12 ·
It’s been a long time since I did my old TS belt but I remember mine was fairly tight slipping it on. Are you fitting it in correct sequence along with having cam sprocket loose so any slack opposite side to tensioner is pulled round?
Also I also seem to recall not using the Alfa tool to tension it but used a lever, as said over tension turn engine over back to TDC make sure timing is still ok then back tension off to mark. Turn over again by hand and recheck tension
 
#13 ·
Yes, I loosened both cam sprockets off and had both the tensioner and the idler very slack as well. I tried following the official way of fitting it anticlockwise from the crank but in the end the only way it goes on is by making sure its at least partially on the cam sprockets and then easing it over the edge of the idler as that has the least sharp edge so it doesn't fray the belt edge. Before I start it up am still wondering why Alfa put the 3 yellow lines on the belt? When setting it up initially it is possible to fix the belt so one of the lines is aligned with the notch on the crankshaft and another one with the mark on the exhaust cam, but after turning the engine over to TDC to check if the camlocks still fit (they do) the belt lines are no longer aligned to the crank and exhaust marks and the manual says they should be but I can't get them to stay aligned.
I'm not keen on the genuine Alfa belt for this model the teeth on the Dayco one have a furrow in them that is probably is an anti slip feature.
 
#14 ·
The lines are only a guide for initial fitting so long as it locks up with tools don’t worry about the lines. I never bother using them when fitting anyway as find hit and miss if they actually align like they are supposed to. Also once you have spin engine over they wouldn’t line up again for several revolutions,not sure how many but seem to recall someone said it’s 100 odd revolutions to get belt back on the lines.
 
#15 ·
Ok thanks for clearing that up what I have found is that despite putting the car in gear after setting TDC when fitting the belt the crank still tends to move a bit ie., the dial indicator changes position but the locks still fit after turning the engine twice not sure how you can stop the crank moving if it matters anyway?
 
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