When Adjusting an old Delta Saw I purchased from an auction, I was at first unable to adjust the trunion by loosing the 3 bolts. After tightening down the bolts the blade would revert back to its original 1/8 off center. After much frustration, I decided to take the saw apart and find the solution. What I found was that the previous owner had removed the old bolts and used standard hex bolts with washers. The washers had "dished" out, causing the trunion to self-center on the dished out washers. After ordering the correct bolts and replacing the "replacements", I was able to finally tune my saw and after scrubbing off much rust, I now have a very well tuned table saw.