I have three identical reels and two more that share the same platform. No matter what I do with, what I call the problem, one I can't get a smooth flow of line out of the drag. It will jerk as it first gives some line and then skip from a steady flow to a stop and go kind of feed. I've checked the drag stack, greased the washers,polished the surfaces, etc., but it still does it.

Any idea what may be causing it?

Not sure if we are talking about casting or spinning gear.

I realize you've already checked the drag stacks, but here's what happened to me.

If it's spinning gear, I just had the same deal on one of the 3 new Vanford 3000s I purchased last year.

This one came out of the box with a "sticky drag," just like you described.

I fished it anyway and waited until hard water to address and repair it.

Couldn't imagine it was something serious considering it was a brand-new reel.

And it wasn't.

Once I opened up the spool and drag stack, one of the two felt washers in the stack was completely misaligned. Not seated properly; instead, it was hanging up on one side of the spool shaft.

It took all of two seconds to place properly within the drag stack, after which the drag was silky smooth like the other reels. So a 'part' worth less than a penny probably, was the culprit.

The other component for me that always gets plenty of attention is the line guide/roller.

If and when that deal gets bound up or is 'dry,' needing some lube,

it can gum things up as far as drag smoothness is concerned.

Also, when it's not spinning smoothly, I feel like it contributes to line twist,

which is everybody's favorite thing.

Good Luck.

A-Jay

For me, it's usually oil getting into the drag or the wrong grease. I buy used reels frequently, 99% of the time, it's oil in the drag.

Did you recently spool it with new line? It's possible you may have over-filled it slightly. The line could be rubbing against the thumbar or the bottom part of the reel frame.

Don't ask me how I know this. 😁

Hmmmm

Spinning or casting??

Carbontex, felt, teflon, shimano's "special" drag washers?

If it is a baitcaster, I would start with checking the line as @Glenn suggested. I would also check the idle gear below the main gear. If it is broken, random weird stuff can occur. Also, the anti reverse ratchet could be slipping off of the main gear. Maybe installed upside down. Both of these are unlikely but a possibility.

On spinning gear, one of my old Stradics did something like this. I swapped the cap from another 2500 Shimano and it fixed it. No idea why.

11 hours ago, FishTank said:

On spinning gear, one of my old Stradics did something like this. I swapped the cap from another 2500 Shimano and it fixed it. No idea why.

No offense, probably because it was over-tightened, and deformed permanently, past the elastic (reversible strain) zone.

You didn't say if this was a new reel or an older one. Could the problem be that anti reverse bearing is starting to go out? I've had two go out on me over the years, and when it happened my first thought was a drag issue.

1 hour ago, bulldog1935 said:

No offense, probably because it was over-tightened, and deformed permanently, past the elastic (reversible strain) zone.

I am fairly certain that, that was not the case but it would definitely do it. The particular reel in question was an old Stradic 2500 FH. I would always check the drag before going out by pulling the line, something I was taught when I was kid. I never set it tight. My guess, it got exposed to too much heat or was stepped on but I really don't know for sure. I swapped the cap from another reel and the issue followed the cap. I ordered another one from Shimano and moved on.