Once I have spool tension adjusted on a SLX XT reel (usually just beyond the point where there is no side to side play in the spool) it takes little to no pressure to turn the knob.  Basically, the issue is that it's becoming looser than I would like during normal use. 

 

I have two identical reels.  I've compared both and see no missing parts, nor does the pad inside the cap seem to be worn out.  I swapped the knobs between the two reels and it seems to have helped, but I'm still curious what might cause this in the first place? 

 

Thanks! 

Just a loose fit. All parts have tolerances. Hopefully swapping them fixes it for ya. If not, a wrap of Teflon tape might.

20 minutes ago, T-Billy said:

Just a loose fit. All parts have tolerances. Hopefully swapping them fixes it for ya. If not, a wrap of Teflon tape might.

Good idea!

 

I'm a QC inspector and work with fasteners all the time...  But it's government work so the simplest fixes don't usually fly ?

Blue loctite might be a viable option.  If it doesn't work, no harm - no foul.

11 minutes ago, QED said:

Blue loctite might be a viable option.  If it doesn't work, no harm - no foul.

X2^^^^. In this case teflon tape may make it harder to get the cap started correctly on the plastic threads, which is touchy to begin with. Strip those and you'll need a new sideplate.

Humm let me understand this correctly, your problem is spool tension knob too easy to turn and become looser while using? 
if this is problem, new O-ring #rd 5320 might help. 
If you have any smaller size oring you could try that as well. I use oRing that come with Fuji hook keeper on my Curado 70.