View Full Version : 18mm Northstar Crankbolt needed

04-07-12, 04:08 PM
In rebuilding my 97 STS N* engine I bought a crankshaft off ebay. The crankshaft did not come with a crankshaft bolt and my original bolt is too small for this crankshaft. Seems that there are crankshafts that have 14mm bolts and ones that have 18mm bolts. I have called all the GM dealerships in my area but all the bigger bolts that they have are about 3 inches longer then my original bolt. Anyone know where I can find a new 18mm crankshaft bolt? I would like to get a new one as I understand they have to have quit a bit of torgue on them and dont want to risk using one that has already been stressed. Any help very much appreciated.


04-09-12, 03:14 PM

04-10-12, 12:39 AM
Seems like the N* came with either a 14mm or a 18mm crankshaft bolt for a number of years. Anyone have a idea why? This N* engine just keeps on throwing out curveballs. :bonkers:

04-10-12, 08:02 PM
The original bolt, unless abused, may be re-used - there is not that much torque applied to it when installed - it's just hard to break free when trying to remove it after many years of being installed. That said, I buggered up the head on my bolt in the removal process - through carelessness, really - ordered a replacement from gmpartsdirect.com