I just went through the hassle of replacing the crankshaft position sensor on a 2000 Bonneville SSEi, 3.8L SC. The hassle is removing the balancer from the crankshaft to get to the position sensor. I finally found 3 inch long 1/4"-28 (yes fine thread) that fit into the balancer to all a puller to be installed. I searched many hardware and auto parts stores with none having anything longer than 2 inches which is too short. 2-1/2 will make it with a very thin 3 slot puller but really you need 3 inch. The special tool J-38197 from GM for the 3.1 and 3.8 engines was very expensive for a simple puller. The only thing about it was it came with the long bolts. I used a normal balancer puller with bolts found at a bolt supply house with no problems. Be careful about where you locate the center puller stud/bolt. Mine was the same identical thread as the crank bolt so it just threaded into the crank. I used a 10 mm - 3/8 drive normal socket with a 3 inch extension placed in the crank hole and pressed against that to remove the balancer. Also replace the crank seal when you do the job. Note the GM seal was cheaper than all parts warehouses and was part number 24504098 ($11) at dealer.

Just some useful info, hope this helps someone in the future.

Thanks for the insight, and with your thread heading it will make it easier to search when someone needs adivce. Well done

I have had mine off twice in the last year. It is preferable to have grade 8 bolts if you can find them. And make sure they are threaded in a good distance. If you pull out those threads it'* going to be very difficult if not impossible to pull the balancer.

If replacing the balancer, make sure the threads in the new one are good and that you can get the bolts in properly, in case you need to pull again later.

Whenever I do this, I leave the crank bolt in partway and push against the head of the bolt.

I'd like to give a little warning to those who haven't tried it, getting that new oil seal in there is not very easy without the tool that is made for it. It'* like putting on a hubcap where one side keeps popping off. And with the crank sticking out, you can't use the old wood block trick either.