I opened up a reel over the weekend that had a brass bushing instead of a bearing under the main gear. Today I swapped the bushing/Bearing out of an older reel. Cleaned the bearing, oiled it, and found no difference in smoothness in ether reel after the swap. Why?

Because they worked.  They wore out quicker, but needed less maintenance. Smoothness would be having the crank stack supported by ball bearings at the base and side plate, packed with grease.  If the AR roller is packed with grease, that will add to smoothness as well.  I don't really like that set up. Frame bearing packed with grease, AR swabbed with quality oil, and side plate bearing (below the drag springs) lightly oiled.  Lots of speed, and smoothness.

This reel has zero ball bearing, but a few metal bushings,and its every bit as smooth as a new reel.

Old Daiwa Black Widow BW2

Great, Thanks for the quick reply,one more question, oil or grease the bushing?

I use oil.  I really don't know what is best.  Grease is probably better for long term use.  Oil is faster, that's for sure.

x2 on each of J's points. Where you'd see real benefits swapping bearings for bushings is in the spool support, like on an old Ambassadeur. Oil should work fine on bushings if you're doing anything close to regular maintenance.

I opened up a reel over the weekend that had a brass bushing instead of a bearing under the main gear. Today I swapped the bushing/Bearing out of an older reel. Cleaned the bearing, oiled it, and found no difference in smoothness in ether reel after the swap. Why?

I know I wasn't asked, but another reason would be the condition of the crank paddles, and whether or not they were bearing driven.

Just an old timers .02 cents

Tight Lines!

The Handle paddles are fine, and the reel free spools pretty good,but there is something a little rough on the retrieve. I have cleaned this reel flushed all bearings. My next guess is the worm gear is too tight.I'll leave the bearing in, and use it till next break down in 6 months or so.