Loud Spool bearings

[lifeofRiley]

I've got a couple reels with loud spool bearings. It seems like when a reel is new the spool bearings are generally quiet. Now I've got some older reels, and the bearings still function well, but even after a cleaning the are noisy on the cast. One set I just rinsed in acetone and applied TSI 321 and they perform well but are still very loud. This is not a high pitched screech, i.e. a dry bearing. It's more of a low constant hiss, such as with dry ceramics. In this case though all my bearings are shimano OEM stainless. I might try removing the shields and using a light grease, such as they come from the factory.

[hoohoorjoo]

If you're using TSI 321, then you are essentially running the bearings dry. The viscosity of oil quietens down a bearing. Oil causes a hydraulic separation of the surfaces-in short, the surfaces never actually touch each other due to a microscopic coating of wet lubricant. With a dry lubricant, there is no such damping, even though the dry lubricant does ultimately prevent friction and wear with a similar mechanical function-it does coat the surfaces and prevents them from touching in that way. But that coating is a solid, so there is no hydraulic noise-damping. The benefit of dry lubricant is that it stays put a lot longer vs. oils that can migrate away quickly. The noise you are experiencing is due to this, plus looser tolerances over time due to wear.....because you can never entirely eliminate friction. Grease will dampen the noise and some vibration even better than oil, but will choke off casting distance on the spool bearings. I tried dry lubricants, and ultimately settled on a low viscosity oil for spool bearings and light grease for the frame bearings.

[diehardbassfishing]

I'd certainly suggest removing bearing shield from one side to facilitate proper cleaning. A broad based recommendation...

Grease in the bearing is a very touchy thing. You mentioned lo vis. That is correct if going this direction. The "danger" is not only limited spool RPM performance, but if the grease impedes the bearing rotation enough, the inner race of the bearing will spin on the shaft. If this is happening, you'll hear a sort of squeal at the peak of the cast. This is the metal to metal sound of the inner race of the bearing against the spool shaft. The bearing at this point is actually acting more like a solid bushing.

I have a Shimano Conquest DC with the orig lite grease. It doesn't show any signs of the "bushing" problem. But I do wonder how much casting distance would increase if changed to oil.

Karl