Dayco Timing Belts Manufacturing Date Code

Hello everyone,

As we all know, the shelf life of a timing belt is a tricky info to get and often is not even available.
I have come across this "backstage" info from Dayco. Since is an important player among OEM equipment and many of us are open to replace the belt with the same manufacturer as the original, I thought it will be helpful info.

So, here it is:
- At the beginning of the infos stamped on the belt, you will have several numbers like (for example):
15434057
15434058
15434059
- The "decoding" goes like this:
15 - year of manufacture
43 - week of manufacture
4 - day of the corresponding week
057, 058, 059 - the position in the production mould (meaning that in production process there is a one-huge width belt which is numbered from 000 to 999 or whatever, which is then cut in slices to the desired functional width).

You should consider yourself "lucky" if you manage to buy a belt having less than 6-8 months of age (statistically speaking).

Also, a not-so-obvious info about these belts, is the following:
- In case you are using the belt on a car that need initial given-value tensioning, you should use a special tool for measuring, delivered also from Dayco
- In order to get the correct tensioning, you should introduce in the tool a code, which is called "testcode" and should be written somewhere on the belt packing box.

I know that such a tensioning tool is available also from Gates, using quite the same (code) principle.

Just hope I made some light in someone else's streets!

Good luck.
Laur