TIMING BELT CHANGE AND INFO
this page is still being built...but below are 2 VERY helpful links that i constantly referenced during my work and really should serve as your main reference from this page (as well as the shop manuals of course!!)
Wally Plumley's Timing belt write up on the 928 owners club site (under the 928 journal listing)
As a starter......The diagrams below are a basic schematic of the belt tensioner system and how the timing belt warning system works on the 928. I was clueless on how it worked until i started tearing it apart. Now i hope the knowledge is shared a bit. I intend to go into it in a bit more detail when the page is done, but....in short, if there is enough tension in the belt, it opposses the pressure of the spring coiled around the insulated "switch/contact" and keeps the circuit closed ie. GROUNDED. If the belt were to become too loose the spring would open the contact (yellow area seen below) thus breaking ground and triggering the.....
BELT TENSION light...
the ! light ....
and a rapid heart rate inlcuding the removal of some leather from your seat as it gets sucked up!!
FYI STUFF....I found in my car, during a little experiment during assembly that the tension light was triggered at a 3.0 reading. I did this by hooking up a continuity tester. I placed one wire on the power connection to the tensioner arm and the other to the adjustment bolt (ground). ..... I then slowly LOOSENEND a properly adjust belt (5.0-5.3) until circuit continuity was lost. When that happened i simpley checked the tension with the factory tool...it showed 3.0!
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