2001 Chevy express 3500, 5.7 liter cab&chassis converted to a Roadtrek RV with 71,000 miles.

So I have watched a few You tube videos on the crankshaft position sensor, checked my shade tree mechanic certificate and it is not expired.

Get ready to pull the starter and wait a minute no wires around it?? The starter wires are all corroded and that needs to be dealt with.

Back to you tube and sensor is located at pully end of engine. But now I am looking at shims and air gaps and relearning, seems some of the replacement sensors come with shims and require the air gap needs to be checked. My GM genuine part 12596851 does not have shims and nothing was said about relearning. Do I need to measure the air gap and might I need shims? Where do I find this info, seems I need a service manual.

Copy and paste from another sensor brand with shims and instructions on relearning.

When installing the new sensor, use an
appropriate gauging compound (not included)
on the end of the sensor to insure there is a
minimum of 0.030 inches air gap. You should
check this in several positions of crank rotation.
If necessary, install a shim and re-check the
air gap. You may add both shims if
needed.Clear all DTC codes and always
perform a crank relearn procedure (this
requires a suitable scan tool). Test drive the
vehicle to insure the concern is corrected.

I have no codes or check engine light if that makes a difference?

 

no shims just bolt on and plug in.
Variation learn procedure must be done afterward with a bidirection diagnostic scan tool.