stop at the rear of the passenger-side sliding door's upper body track

[dbdanimal]

I have a 2003 Dodge Sprinter 3500, T1N, VIN WD0PD544765935189. I need the stop at the rear of the passenger-side sliding door's upper body track — the spring-loaded nylon detent wheel that sits a few inches inside the back end of the track, retracts as the roller passes, then pops back out to catch the roller and hold the door open. On my van it's completely gone. The upper carriage itself is fine and properly captured in the rail; there's just nothing at the end of travel, so the door can run past the end of the track. I need to know whether that detent is available as a standalone part, whether it only comes with the upper track section, or whether the fix is a fabricated stop. If you have a part number for it, I'll take it.