505 timing belt issues

luthier

Well-known member
1000+ Posts
Fellow Frogger
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Oct 31, 2004
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Northern NSW
After putting this beast back together recently I have done two head retensions and it's been going nicely but just not quite right.

Two days ago I lifted the bonnet to show a fellow Pug person and noticed oil coming out from the timing chest.

This engine sat on a bench for 3 years after my house burned down and after I had assembled it with a new timing belt and seals.
However I think that the assembly grease must have gone stiff so on startup both the engine seal and the one on the oil pump shaft must have lost a chunk, so they leaked badly.

OK that's cool, but then I found a badly shredded timing belt. It had strands of metal separating around the inner edge. After 1500K's I've never seen anything like it.



Seems the engine sprocket that drives the belt was particularly worn out, with a big dip in the middle, resulting in very sharp edges. I tried grinding some off but after further investigation realized that I need a new or good one as a replacement. That ain't gunna last 100,000K's with a dip like that.

505sprocketa.jpg


Here's the belt that got oiled up and started to shred.

505timingbelta.jpg


And finally since I now have a copy of Mister Haynes I discovered that I'd been running with the dizzy drive one tooth out, from counting the teeth. So I'm hoping this will finally give me the normal excellence of performance that I expect from this car.
 
i had a mobile mechanic change a belt one time ,to arrive home find it not running ,turns out that on the previous change they had timed the belt incorrectly so rotated the dizzy drive to compensate ,now that all the makes were lined up properly on the belt ,the dizzy drive was out ,from memory the manual gives a picture showing the angle of the offset slot on the drive when the crank is on the timing mark ,on the common rail model there is not a lot of movement ,to adjust the timing at the distributor as the vacuum advance hits stuff ,you probably know this ,pugs PS any chance that something had doped down between the belt and cover to cause that damage ,check the inside of the cover for marks
 
I did have to time it right to one extremity with no more adjustment in that direction so putting it on the correct tooth should help.

The shredding of the belt I put down to the state of the pulley combined with the oil. Oil will make them separate and the inside edge of the pulley had quite sharp edges that weren't even. In fact it almost looked like the pulley had been squashed in a press the way the edges were pushing up, but I put this down to wear, though the cam pulley is dead flat as is the dizzy pulley. It's pretty strange but I think it may have come from a different motor, it's too long ago to remember what I did with it when I had it on the bench at my previous place.
I was surprised that it was fairly soft to file and grind. Maybe someone had an oxy on it sometime which softened it and then doing up the main bolt very tight has actually squashed and distorted it. They are usually very hard right?
 
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