Unfortunately, as written, the Atlas Technical Bulletin instructions for preloading the bearings only works if you have had the left cone off of the spindle. Or if the left cone were a slip or light push fit onto the spindle, which every recent report indicates that it is not. It is apparently on most spindles a moderate interference fit. This is OK once it is properly installed. But not good for circumstances where the collar may be taken off and replaced by a collet closer or in your case a spider unless you understand what you have and don't repeat the instructions. In other words, when you removed the collar in order to install the spider, the bearing probably did not move. Assuming that it was properly installed before you removed the collar, it is now three teeth tighter than zero end float, not 1-1/2.
My recommendation would be to remove the spider. Using a piloted protector and hammer, or better the method of a length of all-thread through the spindle with necessary pieces on each end, pull the spindle back out of the left bearing cone until you have discernible end float. Then follow the instructions to reduce the end float to zero and then go 1-1/2 teeth on the spindle gear farther. In the future, if you switch between threaded collar and some accessory such as the spider, only run the accessory up snug and then lock it. You do not want to move the bearing again.
