OK, now I have replaced the crank sensor, and without GM tool J-they-want-how-much-for-it? It took a lot of patience and a.020 feeler gauge.
Leaving off the plastic splash shield, install the sensor in its pedestal loosely and start the balancer back on, monitoring the space between the back of the balancer and the sensor, making sure you can still reach in from above to get the feeler gauge between them. When the outer interrupter ring is within the sensor's grooves but there's still enough room, get your feeler gauge between the outer edge of the outer interrupter ring and the inner edge of the outermost groove in the sensor. Push the sensor toward the gauge until it contacts the gauge. Remove the gauge and turn the crank over. Listen for any rubbing and check clearance again on two more roughly equidistant locations around the ring. Once there's no more rubbing, tighten the pinch bolt on the sensor pedestal. Tighten the balancer down until it seats. Turn the crank again 360 degrees. If you hear any rubbing, pull the balancer off and try again (and you'll need to remove it again anyway if you want to replace the splash shield).
CJ: I haven't replaced the crank sensor on this car, so I'm sorry, I'm not sure. In general, I know there needs to be an air gap between the magnetic pickup (in this case, two pickups) and an interrupter ring (in this case, on the back of the harmonic balancer). My Haynes manual isn't much help: "A special tool which fits over the end of the crankshaft should be used to check the interrupter rings and adjust the new sensor." But it doesn't give any clues about what this tool is.
Then there's this contradictory advice at autozone. Com that refers to the.025 inch gap you mention: "The crankshaft position sensor is not adjustable for ignition timing, but positioning of the interrupter ring is very important. A clearance of 0.025 inch (0.64mm) is required on either side of the interrupter ring. Failure to maintain adequate clearance will damage the sensor."
I'm not sure whether you're saying the sensor does (in keeping with the first statement) or does not (in keeping with the second statement) have adjustment play in its installation bolts. And do the interrupter rings on the back of the balancer look adjustable to you? I seem to remember them being integral with the balancer.
I think what I would do is just rotate the crankshaft through a turn after getting the balancer back on and make sure I didn't hear any rubbing noise that would indicate the rings making contact with the sensor. That's about the only way I can imagine the rings would damage the sensor, anyway.
Wednesday, August 13th, 2008 AT 8:45 PM