crank sensor

Just wondering how hard it is to change the crank sensor and it's exact location on my '01 K3500, 8.1L w/ Allison?


Thanks for the help.

Well, this reply is probably too late for you, but... the Crankshaft Position Sensor is located at the rear of the engine back against the firewall. Look for the wires at the rear of the engine and the CPS is just to the drivers side of these. You can't see it because it's down low on the back side sticking vertically from the back side. If you're gonna change it, you'll need patience and some extra skin for your hand. Remove the wires first then the single bolt that secures it. Now for the important part. The sensor has one or two o-rings (depending on vintage) along it's shaft which tend to get heat baked and hold the CPS firmly in place. You will need to GENTLY twist back and forth while pulling up on the CPS to remove it. Don't try to rock it back and forth or you risk fracturing the sensor and losing the lower portion down into the netherland. Just rotate and pull up. Some lubricant may help.

GM had a recall for the 2001 8.1L engine CPS but as of now all other tears are SOL from the factory.

yeah the #10 bolt is rough to get at in the 2" of space.all i can say is the shorter the #10 wrench the better. be sure to oil the new "o" rings or ring on the new one that way it will pop in place easily.and the bolt you will think has a thousand threads on it before you get it out and back in.i heard of one guy cutting a hole in his firewall to get to the sensor and put a patch over the hole.i think it took me four hours to change my sensor and three of that was loosening and tightening the bolt.