Timing set with 118 K miles

[Cadman-iac]

That's true,  and it would also help generate service related revenue from the recommended service requirements to maintain the warranty,  if said warranty lasted long enough.

[The Tassie Devil(le)]

........ and it helps force purchase of new vehicles when a major repair is needed on an older vehicle.  Bruce Roe

The theory of "Planned Obsolescence".

Plus, the Factory really didn't care if they broke up after the Warranty Period ran out.   These combinations would have been tested till destruction, and deemed to be good enough for production.   Remember the old Fibre Gears in a Chev inline 6.   They lasted for years, and yes, I had one strip, 60 miles from home.

The "Morse Chain" lasted for a long time, until it stretched that much that it flogged out a hole in the timing chain cover, and the engine lost oil.   I rebuilt a SBC engine which had the hole in the timing cover from chain slop.

Bruce.

["Cadillac Kid" Greg Surfas 15364]

Not to defend anyone because that is not my responsibility, but the 472/500 inch motors as well as the 429's were probably the most engineered/tested/tortured and revised engines of their era.  They were tested in real driving tests for 100's of thousands of miles, and any element that did not hold up was revised and refined or replaced. Now this was in a time where the average time the first owner kept a car was about 3 years and at 10 years old (my 72 eldorado had a listed value of about $500 in 1982) cars were considered past their useful life.  No one contested that fact. 
The one thing the engineers could not test was the actual weathering of components buy the years and unfortunately the Nylon gear coating deteriorated over a 20 year or 120,000 mile period.  Well beyond what it was expected to do. I really do not think that planned obsolescence was on their mind when they went to the high Nickle cast iron block and set up all the tolerances and clearances that resulted in a motor that "with proper maintenance" would wear at the rate of 0.001 per 100, 000 miles and after 300,000 miles would stop wearing.
I got 500K out of the motor in my eldo and at 400,000 I pulled the heads to replace a broken valve spring and found that there was not enough wear to catch a fingernail on the cylinder ridge.
It was just an attempt to lower valve train noise.  Think about it, a cast iron (like the re[placements) cam gear HAS to be cheaper than the Aluminum gear with the (then) added Nylon casting.
Greg Surfas

[Brad Ipsen CLC #737]

Makes a lot more sense than planned obsolescence using more expensive parts that will fail sooner than the cheaper parts.

[Bentley]

Usually you begin to see the timing marking "flutter" during timing

What does "flutter" mean?

Are there any other signs or symptoms of timing gear/chain wear without having to open up the front of the engine to visually inspect it?

[Cadman-iac]

What does "flutter" mean?

Are there any other signs or symptoms of timing gear/chain wear without having to open up the front of the engine to visually inspect it?

What he's referring to is when you are checking the timing,  the mark jumps around from the slack in the chain. It allows the cam to "bounce" back and forth as the chain tightens then goes slack as the load varies on the chain. Basically the mark "flutters" back and forth.

Rick

[Scot Minesinger]

Here is the cam sprocket off a 1965 Cadillac with 125k miles.  The nylon was completely gone and the pieces were all over, including under rocker arm covers.  To me this engine had another 50 miles left. 

If I have the engine cover off, and the timing set is like $60, I would go ahead and replace it.

The 118k miles 472 cam sprocket is in amazing shape - never seen one that nice with that much mileage.

["Cadillac Kid" Greg Surfas 15364]

Scott,
That is why I went to post with it. 
Greg Surfas

[Scot Minesinger]

The 1964 and 1965 cam sprockets and chains were more expensive to manufacture than the 66 and newer because there was more surface area.  The 64 and 65 are nine links wide (4 and 5) and the 66 and newer are just 7 (3 and 4).  I would have thought the 65 would have been in better shape, but maybe the nylon was improved in 1966.

Greg, thanks for posting, that is very unusual.