corrosion and torches

[gofastsandman]

Originally Posted by Bushwacker

Sandy,

Getting that much movement is significant progress! It means the primary seizure area has broken loose, so the Kroil did it's work. Sounds like you've now got a secondary seizure trying to drive the corroded shaft thru the previously seized area. Patience is key! Don't want to screw it up after you got this far! Is there any way you can rotate that shaft? If you could rotate it maybe that would knock off some of the corrosion that has increased the diameter of that section of the shaft. Like the idea of drill and tap, provided the steel in that shaft isn't too hard, since that might allow you to turn the shaft! I'd opt for fine threads(more cross-section and strength/torque capacity) and use an SAE grade 8 bolt (6 hash marks on the bolt head, good for 150,000 psi min tensile strength; grade 6 (4 hash marks) is good for 133 ksi; grade 5 (3 hash marks) will take 105 ksi; grade 1 or 2 (no marks) is only good for 64 ksi, so you lose a LOT of strength going with a cheap bolt! Worst case scenario is the bolt is stronger than the shaft, so it'd strip out the threads you tapped into shaft. In that case, you would then have a good pilot hole to just drill out the shaft. However, one thing you DON'T want to do is break off a grade 8 bolt inside the shaft! Call me and I can give you the torque specs for what ever size and grade of bolt you use. I'd go with the largest size bolt that will fit, maybe a 3/8 or 7/16. Denny

Being patient,
GFS