Another point in which Don is right on, is in taking the drum apart!!!! Better get used to it and while you're staring at it...
... get out some 400 W/D and 3M blending pads, and POLISH the "S*#&" out of every spot of interior blue you can find!!!!!! Especially the transition from drum to vertical and the inside walls... When it's right, and fully loaded, you can "settle" the column just by squeezing the lever a bit more...
... Remember, the first 17 rounds are on the mainspring, the next 15 are on the coil spring... if you have a problem, track where in the string it happens... I know for a fact you'll know a lot more about drums when you're through with this project!!!
... best to all, til...lat'r....GT.....