These remarks are merely my advice, not an official directive from Schulmerich.

The clapper in your bell should swing smoothly and reasonably quietly. Assuming the bell is properly adjusted and rings correctly, if you get a groaning or squeaking noise as the clapper swings, then somethingʼs going on with the bearings. Weʼre NOT talking about the sound of the bell when itʼs struck and rung, weʼre just talking about a noise that occurs as the clapper swings before it actually strikes and rings the bell.

When you look down into the bell, youʼll see the spring at the bottom (either a black piece of plastic or a copper colored piece of metal. There is a slot or notch on either end of the spring up through which protrude the two studs on which are the nuts you turn to adjust the clapper spring tension (making the bell harder or easier to ring.) The bearings are on the sides of this mechanism. For example, as you look down into the bell, if the clapper swings from the 12 oʼclock to 6 oʼclock position (ie toward you and away from you) then the bearings are sticking out of that bottom brass colored unit (thatʼs called the yoke) at the 9 oʼclock and 3 oʼclock positions, so theyʼre to the left and right. The bearings are little white nylon sleeves that go through a hole in either side of that yoke. You might notice a slit in a bearing if you look carefully. Itʼs not broken; thatʼs 
supposed to be there. Through those sleeve bearings turns the metal axle, on which the clapper shaft swings. The axle is probably binding and squeaking inside the bearings.

To hopefully eliminate this noise you need WD-40 lubricant and a Q-tip.

1. Unless you have long handled cotton swabs like doctors use, just take a Q-tip and tape it to a pencil or screwdriver... something that will give you a longer reach than you have with a plain Q-tip (unless weʼre fixing a very small bell.) 
2. Spray enough WD-40 into a small container to make a very small puddle of it. If you have WD-40 that came in a can with the small red cap, you can just spray it into the cap. Otherwise, just use a little cup or glass. 
3. Dip the Q-tip into the puddle of WD-40. You donʼt have to dunk it or immerse it, just stick it in, and the cotton will absorb some of the fluid.
4. Take the Q-tip, reach down into the bell with it, and dab both bearings once with the saturated cotton tip. Wiggle the bell so the clapper swings back and forth and the noise should stop as the WD-40 flows in and “nourishes” the bearing. Donʼt use a lot; donʼt slop it on. You donʼt want WD-40 dribbling down off the bearing into the bottom of the bell. If you slip and touch the inside of the casting, wipe it off as best you can. It wonʼt ruin the bell, but it will eventually discolor a little if you donʼt wipe it off.

Why WD-40 instead of oil? It eventually dries, doesnʼt leave such a sticky residue, and wonʼt catch dust and make a gummy residue as quickly as oil does.