Hi Ani,
YEP, the plastic track that the shaft sits on is the slider or track. If urs has aluminum muzzle, it might be the newer generation, cause all XHD use plastic muzzle........or it was modified to use the aluminum muzzle from the non XHD series of the aluminum guns. If urs is aluminum muzzle, never never pry it open/widen using screwdriver to allow easy rubber entry, it will break. I broke mine twice already.
Once in a while play with all the screws on the JBL, clean and grease it. It is prone to jamming if u r messy like me. Once in a while dismantle the trigger/pistol grip, clean it and grease the side of the sears where it slide against the aluminum housing of the pistol grip. I don't grease my sear contact point. Aluminum oxidized, it will produce powder like dirt. This dirt may act like glue and make dissasembly difficult. Routine cleaning/dissasembly is good for all aluminum JBLs.
JBL shooting line set up are not set for quick disconnect. What I did ( and all my JBL friends ) is I use Riffe 5" Bungie and swivel so that I can use different shaft fast or leave a shaft when it get stuck on a wreck without cutting it.
The JBL slide ring is thin where the shooting line get connected/looped, it does hurt mono fast, even cable too. Just file it down to make it smoothest...that is the best u can do. Next will be to buy fishing supply anti chaffe tube/hose, which are commonly used at looped ends for trolling lure. Never, never use fishing tacke snap shivel to make a quick disconnect at the slide ring, even a 250 pound rated will go STRAIGHT from a 7+kg Trevaly. If u use extra heavy duty shivel/clip to that slide ring, I am afraid the shaft trajectory will be effected. The only way is to use shivel & bungie at the muzzle. Anyway JBL original bungie is not good, it often slipped if big fish pull it, it also oxidized fast.
However, since the hole is small on the JBL muzzzle for shooting line attachment, Riffe bungie shivel can not be attached directly. You got no choice but to crimp a good line as a loop to accept the Riffe bungie assy.
Avoid Kevlar as shooting line cause it tangles fast. I used the 1000 lbs one and sometime it is a mess to do underwater. U can get 500 or 1000 lbs Kevlar from Riffe. It is not called Kevlar but it is. You see, Dupont the owner of Kevlar now charges "brand-name" to any big retailer that sell and mentioned the line as Kevlar......idiots they are. If u ever use Kevlar, I suggest double crimps. I tried single crimp and it always slip. I test them by pulling a car, place the hand brake on the car u r pulling. Let it snap or slipped. My double crimp snap at the line, not at the crimps, so I am doing OK. Kevlar if being knotted is only 70% of its actual rating, this is the weak link. It is too slippery. Making a knot on a Kevlar 1000 lbs is just too bulging, crimps are lower profile. Always use Power Glue or Dupont Kevlar glue to glue the loose end or else teh strands will split and will slip out.
I only use Kevlar as extension line, about a meter at most for converting a shaft from gun-based to breakaway float system, save money.
IYA