I’m trying to identify the cause of a timing belt jumping a tooth after turning the engine over a couple of times having completed the job. I suspect it may have something to do with the crankshaft sprocket .
When taking off the timing belt , both yesterday and again today, i noticed that the crankshaft sprocket was loose enough to rotate by approximately 1 tooth. To clarify the shaft does not rotate during this movement. On my engine (XUD9 DHX2) the woodruff key is located at approximately 11 o’clock when the engine is timed up. So my question is to which end of this range should i position the crankshaft sprocket? In my attempt to put the timing belt the crankshaft sprocket rotated anti-clockwise from fitting the belt and applying tension to the idle pulley and then injection pump. I followed the guidance offered the other day on this site on tensioning the belt and worked a treat.
I reckon other potential causes to the jumped tooth is that the belt tensioner adjustment bolt was not tightened up enough, easily sorted . Unfortunately i forgot to eyeball the position of the plunger so i’m not sure on this one. Or that the crank shaft pulley bolt wasn’t tightened up enough. I’m having to the tighten up the crank shaft pulley bolt by hand with a flexible handle with a metal bar slipped onto the end of it. I applied two part epoxy glue to the threads. Earlier today to got my brother to put the engine in gear and apply the foot brake during the tightening procedure. Is this how it should be done?
Having written this bit before finally posting I’m starting to think that belt may not have jumped and that the pulley bolt was not tight enough allowing the crankshaft sprocket to rotate, given the limited rotation discovered on the sprocket, and hence the impression that the timing has gone adrift when realigning the engine. Could this be a possible explanation?
I’m going to have another go in the next few days but will be working alone. Any views, comments, advice would be appreciated.
Crankshaft sprocket, timing out, 406 1.9TD
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Re: Crankshaft sprocket, timing out, 406 1.9TD
Set the timing up again using the locking pin in the crank under the starter, bolts in cam and pump pulley.
Fit the belt with the crank sprocket turned to the position that gives tension to the injection pump side of the belt, then make sure the tensioner has sprung against the belt as far as it will go, mark all the pulleys including the crank sprocket with tipex or paint also mark the position of the woodruff key with tension on the pump side, then take out all the locking pins/bolts, then, leaving the tensioner bolts loose, put a spanner on the cam pulley bolt (16mm) and tap gently on the spanner forcing tension on the injection pulley side, now tighten the tensioner bolts.
Turn the engine by hand 2 full turns then line up all marks with the tipex mark on the crank pulley in the same position.
Again, tap the cam pulley to the left a little so that tension is tight on the pump side.
Check that the tension feels tight at the tensioner side and all should be well.
Fit the belt with the crank sprocket turned to the position that gives tension to the injection pump side of the belt, then make sure the tensioner has sprung against the belt as far as it will go, mark all the pulleys including the crank sprocket with tipex or paint also mark the position of the woodruff key with tension on the pump side, then take out all the locking pins/bolts, then, leaving the tensioner bolts loose, put a spanner on the cam pulley bolt (16mm) and tap gently on the spanner forcing tension on the injection pulley side, now tighten the tensioner bolts.
Turn the engine by hand 2 full turns then line up all marks with the tipex mark on the crank pulley in the same position.
Again, tap the cam pulley to the left a little so that tension is tight on the pump side.
Check that the tension feels tight at the tensioner side and all should be well.