John's point is newer cars with newer technology and materials also have bad bearings. Its not a matter of bearings get better over time otherwise there would be no failures today. Ferrari had recalls for 458 and California's with crank bearing failure for example. Lots of reasons bearings can fail design tolerance load and oil supply being big ones. Ferrari 348 had 3 different bearings of different sizes for the oil pump bearing, actually different size journals in the block and went from roller (which even I know is a bad idea there) to 2 different ball designs. Its not "newer" bearings were better it was crappy deletion design. Still never read a post of broken belts but lots of posts of someone who knew someone who had a belt failure but I am sure it happens even with new belts. Timing belt threads are always interesting. This thread is interesting if nothing else.
There were a few threads with first-hand accounts of failures. https://www.ferrarichat.com/forum/threads/the-unthinkable-just-happend.527946/ And here's Daniel's photo; https://www.ferrarichat.com/forum/posts/141065451/
I mean I never read a post when a bent snapped due to the belt failing unaided due to time and fatigue. I'm sure it happend somewhere of course... but it is pretty uncommon I think. In those 2 cases you pointed out, they were mechanical interference that caused it not general belt fatigue. Daniels lower fence broke throwing out sharp metal that sheared the belt we tack them these days. (I always wondered what happend to Daniels car) The other one was due to a loose bolt that held the timing shoe and likely got caught between the belt and cog and snapped it. General point being belts are likely not so superior to what they were in 1990 that they can be extended longer. I bet its the same now as it is then is all. Looking like 7 years is the consensus which is the same general consensus found if one searches going back a decade plus with this very question. So time has not changed the opinion which is interesting. I like 7 myself but all those other issues like pulley failure or some bolt not tightened plague my mind daily.
What would be more interesting is a poll is "If your engine will have a failure post service within how many miles will it happen in" With the idea being you can rest at ease after how many miles.
These threads always lead to cases where a belt broke as the result of a mechanical failure in the cam drive system. Think about it for a second. One owner here had a belt jump a coupe of teeth. As a result the intake valves were slamming against the pistons. I can only imagine the shock tension and stretch on the belt when the cam would momentarily stop when the valves contacted the pistons. Yet the belt didn't break.
Yes, this thread's title and poll should be, "How often do you do the major service on your 348?" instead of "timing belt service". In other words, replacing the belt without "doing everything else" is shenanigans at best. And then, of course, there's the competency level of those preforming the "service". https://www.ferrarichat.com/forum/posts/146381171/
The amount of time is very easy to calculate: Change your timing belts today and immediately start reading every thread on timing belts on Ferrari Chat. Once you complete about half of that it will be time to change the belts again
Thanks. It's an acquired skill. Some day I hope to be as good as Ferrari. You can't even tell where they cut and pasted in this shot. Image Unavailable, Please Login
That's the calibrated camshaft gear immobilizing tool. Those are hand built in either Modena Italy or China. I don't recall which. Some peolple cheat and use a vice-grips. Crazy people out there.
Ah, the infamous Porsche IMS issue. I keep the IMS bearing from my Boxster on my desk as a stress reliever (got rid of the rubber squeeze ball). Works pretty well, it's the first design double row type.
Depends if you only caress your car (you never have to do the belts, ever), if you caress and once a year drive it (due every two years due to dry Roth) and if your really drive it like it was meant to be ( 7-10 who knows and it may never give out on you. just saying ♂️