Just in case you don't know, or forgot, these planter prep and maintenance tips:
-on many planters the left disk opener on each row, and sometimes the left closing wheel, have reverse-threaded nuts/bolts. "Lefty-loosey, righty-righty" does't work for those fasteners.
-disk openers often put up a fight and can be tough to get off their stud. Instead of trying to pry them off, use the butt of your fist or a soft-headed hammer to smack the opposite disk. For example, if you're trying to remove the left disk, smack the right disk.
-when re-installing old disk openers, or installing new disk openers, keep track of how many shim washers go on each side. Both sides should use roughly the same number of shims. If one side takes three or more washers than the other side to obtain the recommended contact between the two disk openers, something is bent. Or, if the top edge of one disk opener is rubbing on the planting unit shank after the proper contact between disks is obtained--the shank is bent. Stand behind the unit and eyeball to see if the entire unit is straight up and down or twisted to one side.
-bent shanks are most common on rows next to planter lift wheel frames. They get tweaked out of shape when a basketball-size rock gets wedged between the planting unit and the planter tire. Row units on the ends of planters also can also get twisted if the planter is left in the ground during tight turns on contours.
-On big wing-fold planters, unfold the planter in an open area, lower it, then pull forward while someone else eyeballs across the width of the planter mainframe. Hinge pins and pivots can wear so that the wings fold back several inches under load in planting position. You'll never see the wing flex if you stop and go back and look, because the flex corrects itself when the load is removed from the planter's frame. But that flex can misalign wing-drive jackshaft couplers and give you fits in the field.