Has anyone actually had a timing belt snap on an F355?

That would be a grand total of one for me. Of all the belt failures I have seen 1 has been for a reason other than the belt.

 

So do you mean in like a hundred failures 99 were belt failing?

 

Something to that effect. The idea that the majority of failures are caused by bad tensioner bearings is just not reality. In nearly 40 years I have seen that happen one time.

 

I have seen one other 308 tensioner freezing up, broken the belts, and bent all valves failure. I have heard of one 348 pulley side walls failing, cutting into the belt, bent all valves. I also have removed plenty of old belts looking like new.

 

I would think the heat these engine bays are at must be a contributing factor. Thanks for the revelation.

 

348 pulley fence failure was pretty common.


I had a 355 come in running fine and way overdue for a major service. When we took it apart both tensioner bearings were frozen solid and the belts were doing just fine sliding on the back of them. A 348 design would never get away with that but the other cars the bearing is on the slack side of the belt and it is a very different issue.

In any event tensioner bearing failure is quite rare. Belt failure not nearly so much so. Was in the dealer when 308s were still new cars and so far seen one tensioner failure take out a belt. People have anxiety attacks over bearings and there is no reason.

 

Done 5 repairs on snapped belts in the shop over e years

2 on a 348
2 on a 355
1 on a 308 .

On all occasions it was because the owners didn't want to change at the 5 year point

 

I know of a Fchatter that had his F355 shear the teeth off a timing belt. It was 7 years from the last major service and he had it scheduled the following month for service. It happened while stopped at a light, idling.