I fitted a new timing belt on my '96 300tdi a couple of weeks ago. Searched out all the relevant threads, loads of good info on here, bought a kit and got the spanners out. Simple enough job, four hours and it was all back together and running as sweet as ever.
A couple of days ago on the way home from work the new belt snapped. I cant get the landy in my garage and the weather forecast was high wind and rain so I wasnt able to to tackle it a second time on the drive, so I had it recovered to a local garage for repair (posted about this and got loads of advice on what sort of damage to expect so thanks for that)
I have spent the last few days wondering what I could possibly have done wrong to cause the new belt to fail after a couple of hundred miles. Well, I got the car back today and it turns out that I wasn't at fault.
The cause of the problem was the crankshaft belt sprocket. There was a metal flange on the outer face of the sprocket, presumable to retain the belt. The flange had separated from the sprocket and had effectively started to shave the edge of the belt, and the shaved strands of belt has wrapped around the sprocket effectively increasing its diameter until the combination of a weakened belt and debris on the sprocket became caused it to snap.
The sprocket had seemed perfectly ok when I inspected it, and the garage have told me that, had they done the timing belt first time around, they would not have changed the crankshaft sprocket as a matter of course.
So, I can only offer this as a word of warning to anyone tackling a timing belt; beware the crankshaft pulley. If it has a separate thin metal flange attached to its outer face and not a machined flange, think twice about putting it back on.
A couple of days ago on the way home from work the new belt snapped. I cant get the landy in my garage and the weather forecast was high wind and rain so I wasnt able to to tackle it a second time on the drive, so I had it recovered to a local garage for repair (posted about this and got loads of advice on what sort of damage to expect so thanks for that)
I have spent the last few days wondering what I could possibly have done wrong to cause the new belt to fail after a couple of hundred miles. Well, I got the car back today and it turns out that I wasn't at fault.
The cause of the problem was the crankshaft belt sprocket. There was a metal flange on the outer face of the sprocket, presumable to retain the belt. The flange had separated from the sprocket and had effectively started to shave the edge of the belt, and the shaved strands of belt has wrapped around the sprocket effectively increasing its diameter until the combination of a weakened belt and debris on the sprocket became caused it to snap.
The sprocket had seemed perfectly ok when I inspected it, and the garage have told me that, had they done the timing belt first time around, they would not have changed the crankshaft sprocket as a matter of course.
So, I can only offer this as a word of warning to anyone tackling a timing belt; beware the crankshaft pulley. If it has a separate thin metal flange attached to its outer face and not a machined flange, think twice about putting it back on.
