so i have used my shimano sustain 2500 fg for 2 seasons now and love the reel. it has always been very strong and smooth and puts up with lots of fishing. i caught many 10-20lb carp, 10lb striper, countless bass, and even a 15lb cownose ray with it. i was fishing last week at a saltwater spot and when i got home i rinsed it like i always do. now i feel slight resistance and grinding with it. i am careful around sand but you never know.  i pulled it apart to regrease and clean it up which helped a little, but it isnt the quiet smooth reel i have adored. i feel resistance at specific points when winding it slowly.
anyone have any experience here? is it the ball bearings or is it another part that needs replacing? the bearings are sealed but maybe they need to be reopened and greased(just not sure how). i also hear a squeek when i wind the reel but cant imagine what it could be coming from since i regreased and oiled the reel so carefully.
all help is appreciated, i would prefer not to send it back to shimano for repair.

 

It is hard to say for sure but it sounds like what I experienced with my old sustain 2500 (can't remember the model).  One of the bearings gave out in mine.  I would take it apart and check each bearing, especially the spool bearing.  I stick mine on the end of a pencil, turn them between your fingers and you should feel if it is bad.   Down side to all this, if you go with boca bearings your looking at $100 for a complete set.  

 

One other thing, you mentioned you are getting resistance at specific points. If it is the same place every time, you may have something, maybe sand, on the gearing.  Bottomline, I would take the reel apart again and check everything.

I would check the line roller bearing, I had what sounds like the same problem with 2 stradic fi, it's the same part  #rd 13269.  This may or may or may not be your problem.  Even though the bearing is tucked way back in the assembly and it doesn't get wet, they do corrode, not uncommon.  2 years sounds about right.  If it isn't your problem a good practice is to oil that bearing every few months.

It really, really seems a bearing to me as well, Snookalot may be spot on too.. Either way double check you're bearings. I had a brand new reel with a dry, squealing, rough as cob bearing.... Drop of oil... Bingo!

i will take a look again. thanks for the advice. 

This is a good opportunity to buy some corrosion resistant bearings too. I too think its a bearing.

Reel all the line onto the spool, turn turn the handle with no line touching the roller.  No noise or resistance then the problem is somewhere in the roller bail assembly.

Your problem is probably a bearing, and if it is any bearing the line roller would not be what makes it hard to reel in spots, and only noticeable with weight on the end of the line, but would probably have been noticed getting noisier as it went bad before starting to freeze up. You would need to have it looked at to be sure, there are just to many things that would cause the reel to become hard to turn, some gears, shafts or bearings, possibly even a bushing or nylon sleeve, doubtful but friction ring maybe?? If you are not sure, a tech would need to check it, for this the factory is not nessacary as the reel is no longer under warranty, and most reel services are cheaper and better than factory. I know I don't use factory bearings when I put new bearings in a customers reel, there are usually better options, and have never been a fan of ARB bearings from shimano! The full set of Boca bearings is only around $70.00 for quality Stainless Steel and what most would I would recamend, but if you are not familiar with all the workings of the reel I would have a reel service do the work in case there are other issues beside bearings.